Rare Variants in PLD3 Increase Risk for Alzheimer's Disease in Han Chinese. - Tan, Meng-Shan; Zhu, Jun-Xia; Cao, Xi-Peng; Yu, Jin-Tai; Tan, Lan (J Alzheimers Dis, 2018)
Next-generation sequencing studies had reported that a rare coding variant p.V232M in PLD3 was associated with Alzheimer's disease (AD) and a two-fold increased AD risk in European cohorts. To test whether coding region variants of PLD3 were associated with AD in a large Han Chinese cohort, we performed sequencing to analyze all exons of PLD3, and demonstrated that rare variants p.I163M and c.1020-8G>A conferred considerable risk of late-onset AD (LOAD) in our cohort. Meanwhile, the previously reported p.V232M variant was identified in our AD group. These findings indicate that rare variants of PLD3 may play an important role in LOAD in northern Han Chinese.

Rationale and Design of the Mechanistic Potential of Antihypertensives in Preclinical Alzheimer's (HEART) Trial. - Wharton, Whitney; Goldstein, Felicia C; Tansey, Malú G; Brown, Alexandra L; Tharwani, Sonum D; Verble, Danielle D; Cintron, Amarallys; Kehoe, Patrick G (J Alzheimers Dis, 2018)
Research indicates that certain antihypertensive medications alter Alzheimer's disease (AD) biomarkers in Caucasians. The renin angiotensin system (RAS) regulates blood pressure (BP) in the body and the brain and may directly influence AD biomarkers, including amyloid-β (Aβ) neuropathology, cerebral blood flow (CBF), and inflammatory markers. This hypothesis is supported by studies, including ours, showing that antihypertensives targeting the RAS reduce the risk and slow the progression of AD in Caucasians. While mounting evidence supports a protective role of RAS medications in Caucasians, this mechanism has not been explored in African Americans. To assess the mechanism by which RAS medications modify the brain RAS, cerebrospinal fluid (CSF) Aβ, CBF, and inflammatory markers in African Americans, we are conducting an eight month, Phase Ib randomized, placebo controlled trial, enrolling 60 middle-aged (45-70 years), non-demented individuals, at risk for AD by virtue of a parental history. Participants include normotensive and treated hypertensives that have never been exposed to a RAS medication. Participants are randomized (1 : 1:1) by gender and BP medication use (yes/no) to one of three groups: placebo, or 20 mg, or 40 mg telmisartan (Micardis), to determine the dose required to penetrate the CNS. Our overarching hypothesis is that, compared to placebo, both doses of telmisartan will penetrate the CNS and produce salutary, dose dependent effects on the brain RAS as well as CSF Aβ, CBF, and CSF inflammatory markers in African Americans, over eight months. This manuscript describes the trial rationale and design.
Keywords: African Americans; Aged; Alzheimer Disease; Amyloid beta-Peptides; Antihypertensive Agents; Biomarkers; Blood Pressure; Brain; Clinical Trials, Phase I as Topic; Female; Georgia; Humans; Linear Models; Male; Middle Aged; Randomized Controlled Trials as Topic; Renin-Angiotensin System; Telmisartan

The Rationale and Design of the Reducing Pathology in Alzheimer's Disease through Angiotensin TaRgeting (RADAR) Trial. - Kehoe, Patrick G; Blair, Peter S; Howden, Beth; Thomas, David L; Malone, Ian B; Horwood, Jeremy; Clement, Clare; Selman, Lucy E; Baber, Hannah; Lane, Athene; Coulthard, Elizabeth; Passmore, Anthony Peter; et al. (J Alzheimers Dis, 2018)
BACKGROUND: Anti-hypertensives that modify the renin angiotensin system may reduce Alzheimer's disease (AD) pathology and reduce the rate of disease progression. OBJECTIVE: To conduct a phase II, two arm, double-blind, placebo-controlled, randomized trial of losartan to test the efficacy of Reducing pathology in Alzheimer's Disease through Angiotensin TaRgeting (RADAR). METHODS: Men and women aged at least 55 years with mild-to-moderate AD will be randomly allocated 100 mg encapsulated generic losartan or placebo once daily for 12 months after successful completion of a 2-week open-label phase and 2-week placebo washout to establish drug tolerability. 228 participants will provide at least 182 subjects with final assessments to provide 84% power to detect a 25% difference in atrophy rate (therapeutic benefit) change over 12 months at an alpha level of 0.05. We will use intention-to-treat analysis, estimating between-group differences in outcomes derived from appropriate (linear or logistic) multivariable regression models adjusting for minimization variables. RESULTS: The primary outcome will be rate of whole brain atrophy as a surrogate measure of disease progression. Secondary outcomes will include changes to 1) white matter hyperintensity volume and cerebral blood flow; 2) performance on a standard series of assessments of memory, cognitive function, activities of daily living, and quality of life. Major assessments (for all outcomes) and relevant safety monitoring of blood pressure and bloods will be at baseline and 12 months. Additional cognitive assessment will also be conducted at 6 months along with safety blood pressure and blood monitoring. Monitoring of blood pressure, bloods, and self-reported side effects will occur during the open-label phase and during the majority of the post-randomization dispensing visits. CONCLUSION: This study will identify whether losartan is efficacious in the treatment of AD and whether definitive Phase III trials are warranted.
Keywords: Activities of Daily Living; Alzheimer Disease; Antihypertensive Agents; Atrophy; Blood Pressure Monitors; Brain; Clinical Trials, Phase II as Topic; Disease Progression; Double-Blind Method; Female; Humans; Losartan; Magnetic Resonance Imaging; Male; Multivariate Analysis; Quality of Life; Randomized Controlled Trials as Topic; Regression Analysis; Renin-Angiotensin System

The Rationale Behind the New Alzheimer's Disease Conceptualization: Lessons Learned During the Last Decades. - Molinuevo, José Luis; Minguillon, Carolina; Rami, Lorena; Gispert, Juan Domingo (J Alzheimers Dis, 2018)
In the last decades, progress in neuroimaging techniques and cerebrospinal fluid assays has enabled the characterization of several Alzheimer's disease (AD) biomarkers. This knowledge has shifted the conceptualization of AD from a clinical-pathological construct, where its diagnosis required the presence of dementia with distinct pathologic features, toward a clinical-biological one that recognizes AD as a pathological continuum with a clinical picture that ranges from normal cognition to a dementia stage. Specifically, AD is now divided into three stages: preclinical (abnormal biomarkers and no or only subtle cognitive impairment), mild cognitive impairment or prodromal AD (abnormal pathophysiological biomarkers and episodic memory impairment), and dementia (abnormal biomarkers and clear cognitive and functional impairment). The possibility of assessing AD pathophysiology in vivo before the onset of clinical symptoms in the preclinical stage provides the unprecedented opportunity to intervene at earlier stages of the continuum in secondary prevention trials. Currently, large cohort studies of cognitively healthy participants are undergoing with the main aim of disentangling the natural history of AD to identify individuals with an increased risk of developing AD in the near future to be recruited in these clinical trials. In this paper, we review how the concept of AD has changed over the years as well as discuss the implications of this conceptual change.

Rbfox3/NeuN Regulates Alternative Splicing of Tau Exon 10. - Gu, Jianlan; Chen, Feng; Chu, Dandan; Lu, Ying; Iqbal, Khalid; Gong, Cheng-Xin; Liu, Fei (J Alzheimers Dis, 2018)
Alternative splicing of tau exon 10 generates tau isoforms with three or four microtubule-binding repeats, 3R-tau or 4R-tau, which are under developmental regulation. Dysregulation of tau exon 10 splicing is sufficient to cause neurodegenerative disorders. The RNA-binding Fox3 (Rbfox3), identified as NeuN, regulates RNA processing. However, whether Rbfox3/NeuN regulates tau exon 10 splicing is unknown. In the present study, we found that the developmental expression of 4R-tau coincided with the expression of Rbfox3 in rat brains. Rbfox3 enhanced tau exon 10 inclusion. Tau intron 10 contains UGCAUG, the conservative binding sequence of Rbfox3. Intron 10 of tau pre-mRNA was co-immunoprecipitated by Rbfox3/NeuN. Deletion mutants of the RNA recognition motif (RRM) or three RNA-binding sites of the RRM in Rbfox3/NeuN failed to enhance tau exon 10 inclusion. Rbfox3, specifically expressed in the fetal brain, did not affect tau exon 10 splicing. The level of Rbfox3/NeuN was reduced and was associated with the ratio of 4R-tau/3R-tau in the excitotoxic mouse brains induced by kainic acid. These findings suggest that Rbfox3/NeuN regulates the alternative splicing of tau exon 10 and that decreased Rbfox3/NeuN may lower the ratio of 4R-tau/3R-tau.

Reaction of Amyloid-β Peptide Antibody with Different Infectious Agents Involved in Alzheimer's Disease. - Vojdani, Aristo; Vojdani, Elroy; Saidara, Evan; Kharrazian, Datis (J Alzheimers Dis, 2018)
As early as the 1980s, molecular virologist Ruth Itzhaki began to investigate if there was a causal connection between infections and neurodegenerative disorder. Although the theory has yet to be universally embraced, in 2016 Itzhaki and 33 other scientists from all over the world published a review article in this very journal presenting evidence for the causal role of pathogens in Alzheimer's disease (AD). Exactly how and in what way pathogens affect the induction of AD has yet to be determined, but one possible answer may involve the cross-reactivity of different pathogens with amyloid-β (Aβ). Aβ autoantibodies have been detected in the serum and cerebrospinal fluid of AD patients and in some healthy individuals. In the present study our major goal was to investigate whether antibodies made against Aβ would react both with other brain proteins as well as pathogens associated with AD as a result of molecular mimicry or the binding of bacterial toxins to Aβ42. Our study used a specific monoclonal antibody made against Aβ42, which not only reacted strongly with Aβ42, tau protein, and α-synuclein, but also had from weak to strong reactions with 25 different pathogens or their molecules, some of which have been associated with AD. The homology between peptide stretches of microbial origin and proteins involved in AD could be a mechanism by which antibodies to homologous peptides mount attacks against autoantigens in AD. We concluded that bacterial molecules bind to Aβ protein, forming small oligomers, then encasing pathogens and their molecules to form amyloid plaques, the tell-tale markers of AD. Conversely, these same Aβ peptides induce the production of antibodies to both Aβ42 and bacterial molecules, which may inhibit bacterial pathogenesis, but in the process may promote amyloid plaque formation.

Real World Recruiting of Older Subjects with Mild Cognitive Impairment for Exercise Trials: Community Readiness is Pivotal. - Sanders, Marit L; Stuckenschneider, Tim; Devenney, Kate E; Lawlor, Brian; Schneider, Stefan; Olde Rikkert, Marcel G M (J Alzheimers Dis, 2018)
Prevention trials in subjects with mild cognitive impairment (MCI), especially lifestyle interventions, can be difficult to carry out, particularly the recruitment and retention of subjects. We experienced these challenges in our multi-site one-year exercise trial in MCI, NeuroExercise. Trial recruitment rates differed significantly across sites; the non-medical sport university site, providing free access to a range of group exercise in a sports environment, proved far more successful than memory clinics linked to hospitals. This suggests that non-medical settings and a non-medical research community facilitating physical activities may be important factors in recruitment of subjects with MCI for large prevention trials.
Keywords: Aged; Cognitive Dysfunction; Europe; Exercise; Female; Humans; Life Style; Male; Middle Aged; Patient Selection

Real-World, Multinational, Retrospective Observational Survey of the ADAS-Cog and Associations with Healthcare Resource Utilization in Patients with Alzheimer's Disease. - Ritchie, Craig W; Khandker, Rezaul K; Pike, James; Black, Christopher M; Jones, Eddie; Ambegaonkar, Baishali M (J Alzheimers Dis, 2018)
BACKGROUND: Alzheimer's disease (AD) is one of the most costly conditions, both economically and regarding patient disability and dependency. The huge costs coupled with the predicted increase in prevalence worldwide are likely to challenge healthcare systems in the future. The classic version of the Alzheimer's Disease Assessment Scale-Cognition subscale (ADAS-Cog) is generally seen as the current gold standard primary outcome measure of cognitive symptom progression in dementia clinical trials. OBJECTIVE: This study evaluated the relationship between ADAS-Cog scores as a measure of clinical progression and the healthcare resource utilization (HCRU)-measured burden of cognitive impairment in patients with mild cognitive impairment, AD, or suspected AD in the real world. METHODS: A retrospective observational survey of physicians and their consulting patients with multiple ADAS-Cog scores. Regression models were constructed for HCRU variables (e.g., consultations, hospitalizations, caregiving requirements) with ADAS-Cog rate of change, baseline ADAS-Cog, and their interaction included as exposure variables. RESULTS: 651 patient records were completed by 154 physicians. Approximately 70% of patients had mild to moderate dementia. In 56.7% of patients, clinical progression was maintained/stable from baseline. Mean change in ADAS-Cog (adjusted to 12 months) was 2.8 points and change scores increased with increasing dementia severity. Most HCRU variables increased significantly (p < 0.05; joint test) with increasing ADAS-Cog scores (indexing clinical deterioration). CONCLUSION: The results suggest that further understanding the relationship between HCRU and ADAS-Cog changes in real-world clinical practice could potentially provide a baseline upon which the success of disease-modifying, as well as newer symptomatic, dementia therapies can be judged.

Reappraisal of Aβ40 and Aβ42 Peptides Measurements in Cerebrospinal Fluid of Patients with Alzheimer's Disease. - Fiorini, Michele; Bongianni, Matilde; Benedetti, Maria Donata; Monaco, Salvatore; Zanusso, Gianluigi (J Alzheimers Dis, 2018)
Cerebrospinal fluid (CSF) biomarkers are currently included in the diagnostic criteria for Alzheimer's disease (AD), in particular, decreased concentrations of amyloid-β peptide 1-42 (Aβ42) in the CSF, coupled with increased levels of tau and phosphorylated tau proteins, are supportive of AD diagnosis. To date, the quantification of Aβ42 levels with antibody-dependent immunoassay shows a marked variability among different laboratories and is also affected by different pre-analytical factors, suggesting that part of Aβ42 peptides might be aggregated and thus undetected by antibodies. To bypass an antibody-dependent measurement, we determined the Aβ40 and Aβ42 levels by immunoblot. We analyzed CSF samples from 35 patients with clinical diagnosis of probable AD and from 15 age-matched normal controls; CSF Aβ levels were determined by two different ELISA kits and by immunoblot analysis. Aβ40 levels measured by ELISA were comparable to those obtained by immunoblot, whereas CSF concentrations of Aβ42 measured by ELISA were significantly lower compared to values obtained by immunoblot quantification. Biochemical analysis, following 1D- and 2D-PAGE analysis, showed that the qualitative composition of Aβ peptides in the CSF is similar in AD and controls but different from that of AD brain tissues. Moreover, sedimentation velocity in sucrose gradient of CSF and brain homogenate from AD demonstrated that Aβ42 in CSF is different from Aβ42 in brain in terms of solubility and aggregation state.

Reduced Cerebrovascular Reserve Capacity as a Biomarker of Microangiopathy in Alzheimer's Disease and Mild Cognitive Impairment. - Urbanova, Barbora Soukupova; Schwabova, Jaroslava Paulasova; Magerova, Hana; Jansky, Petr; Marková, Hana; Vyhnálek, Martin; Laczó, Jan; Hort, Jakub; Tomek, Ales (J Alzheimers Dis, 2018)
BACKGROUND: Cerebral microangiopathy in Alzheimer's disease (AD) causes chronic hypoperfusion and probably accelerates neurodegenerative changes. OBJECTIVE: We hypothesize microvascular impairment could be present already in mild cognitive impairment (MCI) and can be revealed using transcranial color-coded sonography (TCCS) and the breath-holding maneuver. METHODS: Three groups of subjects (AD in the stage of dementia, MCI, and cognitively normal controls) with detailed neuropsychological testing and low cerebrovascular burden (no history of stroke, no intra- or extracranial artery stenoses, and no severe vascular lesions on brain MRI), underwent a TCCS assessment of peak systolic (PSV), mean flow (MFV), and end diastolic velocities (EDV) and resistance and pulsatility indices (RI, PI) in large intracranial vessels bilaterally. Cerebrovascular reserve capacity was assessed using the breath-holding index (BHI) in middle cerebral artery (MCA) bilaterally. The ultrasound parameters were compared between the groups, correlated with neuropsychological tests, and compared between amnestic and non-amnestic MCI subtypes. RESULTS: Fourteen AD (3 males, 67.9±11.1 years, MMSE 18.0±4.6), 24 MCI (13 males, 71.9±7.3 years, MMSE 28.0±1.6), and 24 risk factor-matched controls (14 males, 67.8±6.4 years, MMSE 29.1±1.2) were enrolled. Significant differences were found between AD and controls in MFV, EDV, RI, PI in right MCA after breath holding, in PSV, MFV, EDV in left MCA after breath holding, and in BHI on the left side. The left BHI correlated positively with verbal memory test. CONCLUSION: Results show decreased cerebrovascular reserve capacity in AD as a sign of impaired cerebral hemodynamic status without severe underlying atherosclerosis. This can be identified using TCCS and BHI.

Reduced Gray Matter Volume of the Thalamus and Hippocampal Region in Elderly Healthy Adults with no Impact of APOE ɛ4: A Longitudinal Voxel-Based Morphometry Study. - Squarzoni, Paula; Duran, Fabio Luis Souza; Busatto, Geraldo F; Alves, Tania Correa Toledo de Ferraz (J Alzheimers Dis, 2018)
BACKGROUND: Many cross-sectional voxel-based morphometry (VBM) investigations have shown significant inverse correlations between chronological age and gray matter (GM) volume in several brain regions in healthy humans. However, few VBM studies have documented GM decrements in the healthy elderly with repeated MRI measurements obtained in the same subjects. Also, the extent to which the APOE ɛ4 allele influences longitudinal findings of GM reduction in the healthy elderly is unclear. OBJECTIVE: Verify whether regional GM changes are associated with significant decrements in cognitive performance taking in account the presence of the APOE ɛ4 allele. METHODS: Using structural MRI datasets acquired in 55 cognitively intact elderly subjects at two time-points separated by approximately three years, we searched for voxels showing significant GM reductions taking into account differences in APOE genotype. RESULTS: We found global GM reductions as well as regional GM decrements in the right thalamus and left parahippocampal gyrus (p < 0.05, family-wise error corrected for multiple comparisons over the whole brain). These findings were not affected by APOE ɛ4. CONCLUSIONS: Irrespective of APOE ɛ4, longitudinal VBM analyses show that the hippocampal region and thalamus are critical sites where GM shrinkage is greater than the degree of global volume reduction in healthy elderly subjects.
Keywords: Aged; Aging; Apolipoprotein E4; Atrophy; Cross-Sectional Studies; Female; Gray Matter; Healthy Volunteers; Hippocampus; Humans; Longitudinal Studies; Magnetic Resonance Imaging; Male; Organ Size; Thalamus

Regional Distribution, Asymmetry, and Clinical Correlates of Tau Uptake on [18F]AV-1451 PET in Atypical Alzheimer's Disease. - Tetzloff, Katerina A; Graff-Radford, Jonathan; Martin, Peter R; Tosakulwong, Nirubol; Machulda, Mary M; Duffy, Joseph R; Clark, Heather M; Senjem, Matthew L; Schwarz, Christopher G; Spychalla, Anthony J; Drubach, Daniel A; Jack, Clifford R; et al. (J Alzheimers Dis, 2018)
BACKGROUND: Despite common pathology, Alzheimer's disease (AD) can have multiple clinical presentations which pathological studies suggest result from differences in the regional distribution of tau pathology. Positron emission tomography (PET) ligands are now available that can detect tau proteins in vivo and hence can be used to investigate the biological mechanisms underlying atypical AD. OBJECTIVE: To assess regional patterns of tau uptake on PET imaging in two atypical AD variants, posterior cortical atrophy (PCA) and logopenic progressive aphasia (lvPPA). METHODS: Eighteen PCA and 19 lvPPA subjects that showed amyloid-β deposition on PET underwent tau-PET imaging with [18F]AV-1451. Group comparisons of tau uptake in PCA and lvPPA were performed using voxel-level and regional-level analyses. We also assessed the degree of lobar tau asymmetry and correlated regional tau uptake to age and performance on clinical evaluations. RESULTS: Both syndromes showed diffuse tau uptake throughout all cortical regions, although PCA showed greater uptake in occipital regions compared to lvPPA, and lvPPA showed greater uptake in left frontal and temporal regions compared to PCA. While lvPPA showed predominant left-asymmetric tau deposition, PCA was more bilateral. Younger subjects showed greater tau uptake bilaterally in frontal and parietal lobes than older subjects, and sentence repetition, Boston naming test, simultanagnosia, and visuoperceptual function showed specific regional tau correlates. CONCLUSION: Tau deposition is closely related to clinical presentation in atypical AD with age playing a role in determining the degree of cortical tau deposition.

Regional White Matter Hyperintensity Influences Grey Matter Atrophy in Mild Cognitive Impairment. - Vipin, Ashwati; Foo, Heidi Jing Ling; Lim, Joseph Kai Wei; Chander, Russell Jude; Yong, Ting Ting; Ng, Adeline Su Lyn; Hameed, Shahul; Ting, Simon Kang Seng; Zhou, Juan; Kandiah, Nagaendran (J Alzheimers Dis, 2018)
The association between cerebrovascular disease pathology (measured by white matter hyperintensities, WMH) and brain atrophy in early Alzheimer's disease (AD) remain to be elucidated. Thus, we investigated how WMH influence neurodegeneration and cognition in prodromal and clinical AD. We examined 51 healthy controls, 35 subjects with mild cognitive impairment (MCI), and 30 AD patients. We tested how total and regional WMH is related to specific grey matter volume (GMV) reductions in MCI and AD compared to controls. Stepwise regression analysis was further performed to investigate the association of GMV and regional WMH volume with global cognition. We found that total WMH volume was highest in AD but showed the strongest association with lower GMV in MCI. Frontal and parietal WMH had the most extensive influence on GMV loss in MCI. Additionally, parietal lobe WMH volume (but not hippocampal atrophy) was significantly associated with global cognition in MCI while smaller hippocampal volume (but not WMH volume) was associated with lower global cognition in AD. Thus, although WMH volume was highest in AD subjects, it had a more pervasive influence on brain structure and cognitive impairment in MCI. Our study thus highlights the importance of early detection of cerebrovascular disease, as its intervention at the MCI stage might potentially slow down neurodegeneration.

Relationship Between Amyloid-β Positivity and Progression to Mild Cognitive Impairment or Dementia over 8 Years in Cognitively Normal Older Adults. - Dang, Christa; Harrington, Karra D; Lim, Yen Ying; Ames, David; Hassenstab, Jason; Laws, Simon M; Yassi, Nawaf; Hickey, Martha; Rainey-Smith, Stephanie; Robertson, Joanne; Sohrabi, Hamid R; Salvado, Olivier; et al. (J Alzheimers Dis, 2018)
BACKGROUND: Preclinical Alzheimer's disease (AD) is defined by cerebral amyloid-β positivity (Aβ+) in cognitively normal (CN) older adults. OBJECTIVE: To estimate the risk of progression to the symptomatic stages of AD due to PET Aβ+ and the extent that progression was influenced by other demographic, genetic, and clinical characteristics in a large prospective study. METHODS: Fine-Gray subdistribution modeling was used to examine the risk of progression from CN to MCI/dementia due to Aβ+, APOEɛ4 carriage, and their interaction in the Australian Imaging, Biomarkers and Lifestyle (AIBL) flagship study of aging CN cohort (n = 599) over 8 years. RESULTS: 17.7% Aβ+ and 8.1% Aβ-progressed over 8 years (OR: 2.43). Risk of progression for Aβ+ was 65-104% greater than Aβ-. Aβ+ APOEɛ4 carriers were at 348% greater risk than all other participants. Significant risk factors of progression in Aβ+ were age (HR: 1.05), PET SUVR (HR: 2.49) and APOE ɛ4 carriage (HR: 2.63); only age was a significant risk factor in Aβ-(HR: 1.09). Aβ-progressors were not near the threshold for Aβ+. These relationships were not moderated by hypertension, diabetes, obesity, or stroke/TIA. CONCLUSION: Aβ+ is an important prognostic marker for progression from CN to MCI/dementia in older adults and APOEɛ4 carriage provides further predictive value in the presence of Aβ+. These data suggest that Aβ-associated clinical progression is consistent with clinical-pathological models of AD, whereas progression in the absence of elevated Aβ deposition may be the result of neuropathological processes other than AD that accumulate with age.

Relationship Between Body Mass Index, ApoE4 Status, and PET-Based Amyloid and Neurodegeneration Markers in Amyloid-Positive Subjects with Normal Cognition or Mild Cognitive Impairment. - Blautzik, Janusch; Kotz, Sebastian; Brendel, Matthias; Sauerbeck, Julia; Vettermann, Franziska; Winter, Yaroslav; Bartenstein, Peter; Ishii, Kazunari; Rominger, Axel (J Alzheimers Dis, 2018)
Body weight loss in late-life is known to occur at a very early stage of Alzheimer's disease (AD). Apolipoprotein E4 (ApoE4) represents a major genetic risk factor for AD and is linked to an increased cortical amyloid-β (Aβ) accumulation. Since the relationship between body weight, ApoE4, and AD pathology is poorly investigated, we aimed to evaluate whether ApoE4 allelic status modifies the association of body mass index (BMI) with markers of AD pathology. A total of 368 Aβ-positive cognitively healthy or mild cognitive impaired subjects had undergone [18F]-AV45-PET, [18F]-FDG-PET, and T1w-MRI examinations. Composite cortical [18F]-AV45 uptake and [18F]-FDG uptake in posterior cingulate cortex were calculated as surrogates of cortical Aβ load and glucose metabolism, respectively. Multiple linear regressions were performed to assess the relationships between these PET biomarkers with BMI, present cognitive performance, and cognitive changes over time. Multivariate analysis of covariance was conducted to test for statistical differences between ApoE4/BMI categories on the PET markers and cognitive scores. In carriers of the ApoE4 allele only, BMI was inversely associated with cortical amlyoid load (β= -0.193, p < 0.005) and recent cognitive decline (β= -0.209, p < 0.05), and positively associated with cortical glucose metabolism in an AD-vulnerable region (β= 0.145, p < 0.05). ApoE4/BMI category analyses demonstrated lower Aβ load, higher posterior cingulate glucose metabolism, improved cognitive performance, and lower progression of cognitive decline in obese ApoE4 carriers. The effect of ApoE4 in promoting the accumulation of cortical amyoid, which may itself be a driver for weight loss, may be moderated by altering leptin signaling in the hypothalamus.

The Relationship between Obstructive Sleep Apnea and Alzheimer's Disease. - Andrade, Andreia G; Bubu, Omonigho M; Varga, Andrew W; Osorio, Ricardo S (J Alzheimers Dis, 2018)
Obstructive sleep apnea (OSA) and Alzheimer's disease (AD) are highly prevalent conditions with growing impact on our aging society. While the causes of OSA are now better characterized, the mechanisms underlying AD are still largely unknown, challenging the development of effective treatments. Cognitive impairment, especially affecting attention and executive functions, is a recognized clinical consequence of OSA. A deeper contribution of OSA to AD pathogenesis is now gaining support from several lines of research. OSA is intrinsically associated with disruptions of sleep architecture, intermittent hypoxia and oxidative stress, intrathoracic and hemodynamic changes as well as cardiovascular comorbidities. All of these could increase the risk for AD, rendering OSA as a potential modifiable target for AD prevention. Evidence supporting the relevance of each of these mechanisms for AD risk, as well as a possible effect of AD in OSA expression, will be explored in this review.

Relationship of Area of Soft Drusen in Retina with Cerebral Amyloid-β Accumulation and Blood Amyloid-β Level in the Elderly. - Shoda, Chiho; Kitagawa, Yorihisa; Shimada, Hiroyuki; Yuzawa, Mitsuko; Tateno, Amane; Okubo, Yoshiro (J Alzheimers Dis, 2018)
BACKGROUND: Histopathological studies have confirmed that soft drusen contains amyloid-β (Aβ). OBJECTIVE: To examine the relationship between the area of soft drusen in the macular area and cerebral Aβ accumulation or plasma Aβ level in elderly persons without dementia. METHODS: Fourteen consecutive patients (18 eyes) aged ≥50 years with macular soft drusen were studied prospectively. From color fundus photographs, the area of soft drusen (pixel) within a 6,000 μm diameter with the macula as center was measured. Standard uptake value ratio (SUVR) was obtained from positron emission tomography using florbetapir, which indicates the ratio of cerebral cortical-to-cerebellar Aβ accumulation. Ratio of plasma Aβ1-42 to Aβ1-40 level was calculated. RESULTS: Mean age was 73.3±7.6 years. The soft drusen area was 4.32±2.42 mm2. The SUVR was 1.08±0.15. Plasma Aβ1-42/Aβ1-40 ratio was 0.17±0.08. When SUVR ≥1.10 was defined as positive and <1.10 as negative, the soft drusen area in SUVR-positive patients (6.19±1.14 mm2) was significantly (p = 0.0043) larger than that in SUVR-negative patients (3.13±2.27 mm2). Multivariate regression analysis showed that SUVR positivity correlated with soft drusen area (p = 0.0484) and with Voxel-based Specific Regional Analysis System for Alzheimer's Disease score (p = 0.0360). However, there was no correlation with gender (p = 0.1921), age (p = 0.2361), Alzheimer's Disease Assessment Scale score (p = 0.6310), Mini-Mental State Examination score (p = 0.4246), or plasma Aβ1-42/Aβ1-40 ratio (p = 0.8398). CONCLUSION: Among elderly persons without dementia, the area of soft drusen was larger in those with more extensive cerebral Aβ accumulation. The area of soft drusen may be a biomarker of cerebral Aβ accumulation.

Relationships between Cognition and Activities of Daily Living in Alzheimer's Disease During a 5-Year Follow-Up: ALSOVA Study. - Saari, Toni; Hallikainen, Ilona; Hänninen, Tuomo; Räty, Hannu; Koivisto, Anne (J Alzheimers Dis, 2018)
BACKGROUND: Impaired cognition and activities of daily living (ADL) are core symptoms of Alzheimer's disease (AD), but their relationship is unclear. OBJECTIVES: To explore relationships between cognitive domains and functional ability during 5-year follow-up in persons with AD. METHODS: We analyzed ALSOVA study data from 236 individuals with very mild or mild AD at baseline. The CERAD Neuropsychological Battery (CERAD-NB) was used as a cognitive measure and Alzheimer's Disease Cooperative Study ADL (ADCS-ADL) as a functional measure, analyzing the IADL and BADL sub-scores separately. Annual regression models and linear mixed-effect models (LMMs) covering a 5-year follow-up period were used. RESULTS: Annually, the CERAD-NB total and especially Verbal Fluency, Clock Drawing, and Constructional Praxis were associated with the total ADCS-ADL and IADL scores increasingly yet modestly, and to a lesser extent the BADL score. In the LMMs, the same measures and MMSE were associated with ADL. CONCLUSION: Measures of executive function and visuoconstructive skills appear to be associated with caregiver-interview based ADL measure during the progression of AD.

Relationships Between Lower Olfaction and Brain White Matter Lesions in Elderly Subjects with Mild Cognitive Impairment. - Heinrich, Juliette; Vidal, Jean-Sébastien; Simon, Axelle; Rigaud, Anne-Sophie; Hanon, Olivier; Epelbaum, Jacques; Viollet, Cécile; Duron, Emmanuelle (J Alzheimers Dis, 2018)
BACKGROUND: Olfactory impairment is reported in mild cognitive impairment (MCI) and Alzheimer's disease (AD) and is associated with hippocampal atrophy. In elderly people, dementia with AD neuropathology and white matter lesions (WML) is common. In this context, olfactory impairment could also depend on the presence of WML. OBJECTIVE: To assess the cross-sectional relationship between olfaction and WML in elderly subjects with MCI. METHODS: Consecutive subjects, >65 years old, diagnosed as MCI after a comprehensive neuropsychological assessment in an expert memory center, with a brain MRI performed within a year and without major depressive state, were included. Olfaction was assessed by the Brief Smell Identification Test (BSIT). Two trained neuroradiologists, blind to cognitive and olfaction status, visually assessed hippocampal atrophy according to Scheltens' scale and WML according to Fazekas criteria. RESULTS: Seventy-five MCI subjects (mean age (SD) = 77.1 (6.2) years, 74.7% of women) were included. After adjustment for age and sex, factors associated with low BSIT scores were older age (p = 0.007), lower BMI (p = 0.08), lower MMSE score (p = 0.05), lower FCRST (p = 0.008), hippocampal atrophy (p = 0.04), periventricular WML (p = 0.007), and deep WML burden (p = 0.005). In multivariate analysis, severe deep WML (OR (95% CI) = 6.29 (1.4-35.13), p = 0.02) remained associated with low BSIT score independently from hippocampal atrophy. CONCLUSION: In elderly MCI subjects, low olfactory performances are associated with WML, whose progression may be slowed by vascular treatments. A longitudinal study to evaluate whether the progression of WML, hippocampal atrophy and low olfactory function, can predict accurately conversion from MCI to dementia is ongoing.
Keywords: Aged; Aged, 80 and over; Alzheimer Disease; Atrophy; Cognitive Dysfunction; Cross-Sectional Studies; Disease Progression; Female; Humans; Logistic Models; Longitudinal Studies; Magnetic Resonance Imaging; Male; Multivariate Analysis; Neuropsychological Tests; Olfaction Disorders; Severity of Illness Index; White Matter

Relevance of Coded Prodromal Mild Cognitive Impairment in the Routine Treatment of Patients with Dementia in Germany. - Bohlken, Jens; Kostev, Karel (J Alzheimers Dis, 2018)
Little is known about the impact of prior mild cognitive impairment (MCI, ICD-10: F06.7) diagnosis on the time to dementia diagnosis, anti-dementia drug therapy, and treatment persistence in patients with dementia (PWD). Patients with dementia diagnoses who started anti-dementia therapy between January 2010 and December 2016 were selected from 203 neurological/psychiatric practices in the Disease Analyzer databank (IQVIA). Patients with a history of MCI were compared to non-MCI controls in terms of demographic characteristics, anti-dementia therapy, and the rate of persistence with anti-dementia drugs. For persistence analyses, a 1:1 matching procedure was used based on age, gender, type of residence, and depression and dementia diagnosis. Persistence was represented using Kaplan-Meier curves. A Cox regression analysis was used to determine the influence of MCI diagnosis on persistence with anti-dementia drugs. 339 PWD with MCI diagnoses and 339 controls were available for analysis. PWD with MCI were younger (78.9 versus 80.4 years), less likely to live in a nursing home (8.5% versus 22.5%), more frequently received donepezil (40.1% versus 33.7%), and more likely to exhibit comorbid depression (29.6% versus 16.9%). There was no association between the risk of treatment discontinuation and prior MCI diagnosis. After 24 months, 40% versus 41.1% of patients had discontinued treatment. The prior MCI diagnosis presumably led to an earlier diagnosis of dementia and earlier anti-dementia treatment. Treatment continuity did not differ, which would suggest that it does not depend on prior MCI diagnosis but on the behavior of patients and their caregiving relatives.

The Relevance of Iron in the Pathogenesis of Multiple System Atrophy: A Viewpoint. - Kaindlstorfer, Christine; Jellinger, Kurt A; Eschlböck, Sabine; Stefanova, Nadia; Weiss, Günter; Wenning, Gregor K (J Alzheimers Dis, 2018)
Iron is essential for cellular development and maintenance of multiple physiological processes in the central nervous system. The disturbance of its homeostasis leads to abnormal iron deposition in the brain and causes neurotoxicity via generation of free radicals and oxidative stress. Iron toxicity has been established in the pathogenesis of Parkinson's disease; however, its contribution to multiple system atrophy (MSA) remains elusive. MSA is characterized by cytoplasmic inclusions of misfolded α-synuclein (α-SYN) in oligodendrocytes referred to as glial cytoplasmic inclusions (GCIs). Remarkably, the oligodendrocytes possess high amounts of iron, which together with GCI pathology make a contribution toward MSA pathogenesis likely. Consistent with this observation, the GCI density is associated with neurodegeneration in central autonomic networks as well as olivopontocerebellar and striatonigral pathways. Iron converts native α-SYN into a β-sheet conformation and promotes its aggregation either directly or via increasing levels of oxidative stress. Interestingly, α-SYN possesses ferrireductase activity and α-SYN expression underlies iron mediated translational control via RNA stem loop structures. Despite a correlation between progressive putaminal atrophy and iron accumulation as well as clinical decline, it remains unclear whether pathologic iron accumulation in MSA is a secondary event in the cascade of neuronal degeneration rather than a primary cause. This review summarizes the current knowledge of iron in MSA and gives evidence for perturbed iron homeostasis as a potential pathogenic factor in MSA-associated neurodegeneration.
Keywords: alpha-Synuclein; Brain; Humans; Inclusion Bodies; Iron; Magnetic Resonance Imaging; Multiple System Atrophy; Oligodendroglia; Parkinsonian Disorders

Religious Orders Study and Rush Memory and Aging Project. - Bennett, David A; Buchman, Aron S; Boyle, Patricia A; Barnes, Lisa L; Wilson, Robert S; Schneider, Julie A (J Alzheimers Dis, 2018)
BACKGROUND: The Religious Orders Study and Rush Memory and Aging Project are both ongoing longitudinal clinical-pathologic cohort studies of aging and Alzheimer's disease (AD). OBJECTIVES: To summarize progress over the past five years and its implications for understanding neurodegenerative diseases. METHODS: Participants in both studies are older adults who enroll without dementia and agree to detailed longitudinal clinical evaluations and organ donation. The last review summarized findings through the end of 2011. Here we summarize progress and study findings over the past five years and discuss new directions for how these studies can inform on aging and AD in the future. RESULTS: We summarize 1) findings on the relation of neurobiology to clinical AD; 2) neurobiologic pathways linking risk factors to clinical AD; 3) non-cognitive AD phenotypes including motor function and decision making; 4) the development of a novel drug discovery platform. CONCLUSION: Complexity at multiple levels needs to be understood and overcome to develop effective treatments and preventions for cognitive decline and AD dementia.

REM Sleep Behavior Disorder and Alzheimer's Disease: Definitely No Relationship? - Galbiati, Andrea; Carli, Giulia; Hensley, Michael; Ferini-Strambi, Luigi (J Alzheimers Dis, 2018)
Rapid eye movement (REM) sleep behavior disorder (RBD) is a REM sleep parasomnia characterized by the loss of the typical muscular atonia present during healthy REM sleep. RBD can occur in the absence of other neurological conditions or in association with a neurodegenerative disorder. It is now well established that RBD is a strong predictor of neurodegeneration, in particular synucleinopathies, such as Parkinson's disease, Lewy body dementia (LBD), or multiple system atrophy. However, some longitudinal studies report that a minority of patients develop either overlapping form of dementia or Alzheimer disease's (AD). Although AD is reported as a possible development in patients with RBD, it is in a limited number of cases and there are concerns about the accuracy of the diagnostic criteria. Neuropsychological impairments identified in cross-sectional studies of RBD patients describe a profile similar to that observed in dementia related to synucleinopathies. However, only deficits in executive function predict the development of neurodegeneration. Longitudinal studies reported the development of AD in RBD patients in about 7% of cases with variability ranging from 3% and 11%. Since the majority of longitudinal investigations do not report AD as a possible development for RBD patients the proportion may be overestimated. The study of the relationship between RBD and AD may be confounded by two factors that lead to misdiagnosis: the use of clinical criteria alone and the overlap between the clinical features and neuropathology of AD and LBD. Future studies to investigate this association must use updated diagnostic criteria incorporating ancillary investigations.

Reproducibility of Alzheimer's Disease Cerebrospinal Fluid-Biomarker Measurements under Clinical Routine Conditions. - Vogelgsang, Jonathan; Wedekind, Dirk; Bouter, Caroline; Klafki, Hans-W; Wiltfang, Jens (J Alzheimers Dis, 2018)
Analysis of cerebrospinal fluid (CSF) is one of the key tools for the state-of-the-art differential diagnosis of dementias. Dementia due to Alzheimer's disease (AD) is characterized by elevated CSF levels of total Tau (tTau) and phospho-181-Tau (pTau) and low CSF amyloid-β42 (Aβ42). Discrepancies in the laboratory analysis of human materials are well known and much effort has been put into harmonization procedures. In this study, we measured CSF biomarkers of more than 100 patients obtained under clinical routine conditions in two different clinical laboratories. The CSF biomarker levels obtained from the two different sites were significantly correlated: R2 = 0.7129 (tTau, p < 0.001), 0.7914 (pTau, p < 0.001), 0.5078 (Aβ42, p < 0.001), 0.5739 (Aβ40, p < 0.001), and 0.4308 (Aβ42/40, p < 0.001). However, the diagnostic classifications of the Aβ42, tTau, and pTau levels of identical subjects into normal versus pathological range made by the two different sites showed substantial discrepancies (31.5%, 29.6%, and 25.0% discordant cases, respectively). Applying Aβ42/40, instead of CSF Aβ42 alone, lead to a reduction of the discordant cases to 16.8%. Our findings suggest that CSF Aβ42/40 can outperform Aβ42 as a biomarker for AD neuropathology, not only under well-controlled study conditions but also in real life clinical routine. Thus, we recommend the inclusion of Aβ42/40 as a CSF biomarker in the diagnostic procedure.

Rethinking the Reserve with a Translational Approach: Novel Ideas on the Construct and the Interventions. - Serra, Laura; Gelfo, Francesca; Petrosini, Laura; Di Domenico, Carlotta; Bozzali, Marco; Caltagirone, Carlo (J Alzheimers Dis, 2018)
The concept of brain, cognitive, and neural reserves has been introduced to account for the apparent discrepancies between neurological damage and clinical manifestations. However, these ideas are yet theoretical suggestions that are not completely assimilated in the clinical routine. The mechanisms of the reserves have been extensively studied in neurodegenerative pathologies, in particular in Alzheimer's disease. Both human and animal studies addressed this topic by following two parallel pathways. The specific aim of the present review is to attempt to combine the suggestions derived from the two different research fields to deepen the knowledge about reserves. In fact, the achievement of a comprehensive theoretical framework on reserve mechanisms is an essential step to propose well-timed interventions tailored to the clinical characteristics of patients. The present review highlights the importance of addressing three main aspects: the definition of reserve proxy measures, the interaction between reserve level and therapeutic interventions, and the specific time-window of reserve efficacy.

Retinoic Acid Enhances Apolipoprotein E Synthesis in Human Macrophages. - Clemens, Vera; Regen, Francesca; Le Bret, Nathalie; Heuser, Isabella; Hellmann-Regen, Julian (J Alzheimers Dis, 2018)
Apolipoprotein E (ApoE) represents a pivotal target in Alzheimer's disease (AD) and is modulated through retinoic acid (RA), an endogenous neuroprotective and anti-inflammatory compound. A major source of ApoE are microglia, which are pathologically activated in AD. Activated microglia are known to block RA signaling. This suggests a vicious cycle between inflammation, RA signaling, and ApoE homeostasis in AD pathogenesis. To test this hypothesis, we investigated effects of RA and proinflammatory activation on ApoE synthesis in primary human macrophage-derived microglial-like cells. Our results indicate that proinflammatory activation attenuates ApoE synthesis, an effect blocked by RA.
Keywords: Alzheimer Disease; Apolipoproteins E; Cells, Cultured; Humans; Macrophages; Signal Transduction; Tretinoin

A Retrospective Belgian Multi-Center MRI Biomarker Study in Alzheimer's Disease (REMEMBER). - Niemantsverdriet, Ellis; Ribbens, Annemie; Bastin, Christine; Benoit, Florence; Bergmans, Bruno; Bier, Jean-Christophe; Bladt, Roxanne; Claes, Lene; De Deyn, Peter Paul; Deryck, Olivier; Hanseeuw, Bernard; Ivanoiu, Adrian; et al. (J Alzheimers Dis, 2018)
BACKGROUND: Magnetic resonance imaging (MRI) acquisition/processing techniques assess brain volumes to explore neurodegeneration in Alzheimer's disease (AD). OBJECTIVE: We examined the clinical utility of MSmetrix and investigated if automated MRI volumes could discriminate between groups covering the AD continuum and could be used as a predictor for clinical progression. METHODS: The Belgian Dementia Council initiated a retrospective, multi-center study and analyzed whole brain (WB), grey matter (GM), white matter (WM), cerebrospinal fluid (CSF), cortical GM (CGM) volumes, and WM hyperintensities (WMH) using MSmetrix in the AD continuum. Baseline (n = 887) and follow-up (FU, n = 95) T1-weighted brain MRIs and time-linked neuropsychological data were available. RESULTS: The cohort consisted of cognitively healthy controls (HC, n = 93), subjective cognitive decline (n = 102), mild cognitive impairment (MCI, n = 379), and AD dementia (n = 313). Baseline WB and GM volumes could accurately discriminate between clinical diagnostic groups and were significantly decreased with increasing cognitive impairment. MCI patients had a significantly larger change in WB, GM, and CGM volumes based on two MRIs (n = 95) compared to HC (FU>24months, p = 0.020). Linear regression models showed that baseline atrophy of WB, GM, CGM, and increased CSF volumes predicted cognitive impairment. CONCLUSION: WB and GM volumes extracted by MSmetrix could be used to define the clinical spectrum of AD accurately and along with CGM, they are able to predict cognitive impairment based on (decline in) MMSE scores. Therefore, MSmetrix can support clinicians in their diagnostic decisions, is able to detect clinical disease progression, and is of help to stratify populations for clinical trials.

A Review of the Familial Alzheimer's Disease Locus PRESENILIN 2 and Its Relationship to PRESENILIN 1. - Jiang, Haowei; Jayadev, Suman; Lardelli, Michael; Newman, Morgan (J Alzheimers Dis, 2018)
PRESENILIN 1 (PSEN1) and PRESENILIN 2 (PSEN2) genes are loci for mutations causing familial Alzheimer's disease (fAD). However, the function of these genes and how they contribute to fAD pathogenesis has not been fully determined. This review provides a summary of the overlapping and independent functions of the PRESENILINS with a focus on the lesser studied PSEN2. As a core component of the γ-secretase complex, the PSEN2 protein is involved in many γ-secretase-related physiological activities, including innate immunity, Notch signaling, autophagy, and mitochondrial function. These physiological activities have all been associated with AD progression, indicating that PSEN2 plays a particular role in AD pathogenesis.

Revolution of Alzheimer Precision Neurology. Passageway of Systems Biology and Neurophysiology. - Hampel, Harald; Toschi, Nicola; Babiloni, Claudio; Baldacci, Filippo; Black, Keith L; Bokde, Arun L W; Bun, René S; Cacciola, Francesco; Cavedo, Enrica; Chiesa, Patrizia A; Colliot, Olivier; Coman, Cristina-Maria; et al. (J Alzheimers Dis, 2018)
The Precision Neurology development process implements systems theory with system biology and neurophysiology in a parallel, bidirectional research path: a combined hypothesis-driven investigation of systems dysfunction within distinct molecular, cellular, and large-scale neural network systems in both animal models as well as through tests for the usefulness of these candidate dynamic systems biomarkers in different diseases and subgroups at different stages of pathophysiological progression. This translational research path is paralleled by an "omics"-based, hypothesis-free, exploratory research pathway, which will collect multimodal data from progressing asymptomatic, preclinical, and clinical neurodegenerative disease (ND) populations, within the wide continuous biological and clinical spectrum of ND, applying high-throughput and high-content technologies combined with powerful computational and statistical modeling tools, aimed at identifying novel dysfunctional systems and predictive marker signatures associated with ND. The goals are to identify common biological denominators or differentiating classifiers across the continuum of ND during detectable stages of pathophysiological progression, characterize systems-based intermediate endophenotypes, validate multi-modal novel diagnostic systems biomarkers, and advance clinical intervention trial designs by utilizing systems-based intermediate endophenotypes and candidate surrogate markers. Achieving these goals is key to the ultimate development of early and effective individualized treatment of ND, such as Alzheimer's disease. The Alzheimer Precision Medicine Initiative (APMI) and cohort program (APMI-CP), as well as the Paris based core of the Sorbonne University Clinical Research Group "Alzheimer Precision Medicine" (GRC-APM) were recently launched to facilitate the passageway from conventional clinical diagnostic and drug development toward breakthrough innovation based on the investigation of the comprehensive biological nature of aging individuals. The APMI movement is gaining momentum to systematically apply both systems neurophysiology and systems biology in exploratory translational neuroscience research on ND.
Keywords: Alzheimer Disease; Animals; Brain; Humans; Neurology; Neurophysiology; Precision Medicine; Systems Biology; Translational Medical Research

Risk Factors Associated with Cortical Thickness and White Matter Hyperintensities in Dementia Free Okinawan Elderly. - Silbert, Lisa C; Lahna, David; Promjunyakul, Nutta-On; Boespflug, Erin; Ohya, Yusuke; Higashiuesato, Yasushi; Nishihira, Junko; Katsumata, Yuriko; Tokashiki, Takashi; Dodge, Hiroko H (J Alzheimers Dis, 2018)
BACKGROUND: Cortical gray matter (GM) and white matter (WM) deterioration are signals of neurodegeneration and increased dementia risk; however, their specific etiologies in dementia-free aging is unclear. OBJECTIVE: The objective of this study was to examine potentially modifiable risk factors of GM and WM degeneration in a well-characterized cohort of dementia-free elderly. METHODS: 96 Okinawan elderly participants (age 83.6) from the Keys to Optimal Cognitive Aging Project (KOCOA) underwent MRI and cognitive evaluation. Serum markers of inflammation (interleukin-6 (IL-6), high sensitivity C-reactive protein), cerebrovascular disease (systolic blood pressure (SBP) 140+, hemoglobin A1C (HgbA1C), total cholesterol), and essential minerals (copper (Cu), magnesium, and calcium) were examined in relation to mean cortical thickness (MCT) and white matter hyperintensities (WMH), adjusting for age and gender. Voxel-based morphometry (VBM) analyses identified relationships between regional GM density and the above markers. RESULTS: Decreased MCT was associated with SBP 140 + (p = 0.029) and increased serum IL-6 (p = 0.036), HgbA1C (p = 0.002), and Cu (p = 0.025). In VBM analyses, increased IL-6, HgbA1C, and Cu were associated with decreased GM density in temporal lobe regions. HgbA1C (p = 0.004) was associated with greater WMH volume. CONCLUSIONS: Peripheral markers of Cu, CVD risk, and inflammation are associated with MRI-markers of decreased brain health in dementia-free Okinawan elderly, with regional cortical thinning in areas involved in early accumulation of Alzheimer's disease pathology. Results identify potentially modifiable biomarkers as targets in the prevention of dementia in older individuals.

Risk Factors of Rapid Cognitive Decline in Alzheimer's Disease and Mild Cognitive Impairment: A Systematic Review and Meta-Analysis. - Song, Ya-Nan; Wang, Ping; Xu, Wei; Li, Jie-Qiong; Cao, Xi-Peng; Yu, Jin-Tai; Tan, Lan (J Alzheimers Dis, 2018)
BACKGROUND: The conclusions about risk factors for rapid cognitive decline (RCD) in Alzheimer's disease (AD) and mild cognitive impairment (MCI) remain contradictory. OBJECTIVE: To explore the factors predicting RCD in AD and MCI. METHODS: We searched the PubMed, EMBASE, and the Cochrane Library from inception to May 27, 2017 for studies investigating factors associated with faster cognitive progression in AD and MCI. Effect sizes were meta-analyzed using fixed-effects and random-effects models. RESULTS: Fifty-three studies with 14,330 patients (12,396 AD and 1,934 MCI) were included in the systematic review. The following factors were identified to increase the risk of RCD in AD: Apolipoprotein E4 (ApoE4) (SMD [95% CI]: 0.52 [0.06,0.98]), early age at onset (SMD [95% CI]: -0.42 [-0.71, -0.13]), high level of education (RR = 2.05, 95% CI = 1.26 to 3.33), early appearance of extrapyramidal signs (RR = 2.18; 95% CI = 1.30 to 3.67), and neuropsychiatric conditions including hallucination (RR = 2.01, 95% CI = 1.40 to 2.87), strolling (RR = 1.99, 95% CI = 1.38 to 2.86), agitation (RR = 1.66, 95% CI = 1.23 to 2.24), and psychosis (RR = 1.42, 95% CI = 1.07 to 1.89). Instead, advanced age (≥75 years) (RR = 0.96, 95% CI = 0.93 to 0.99), diabetes (RR = 0.57; 95% CI = 0.35 to 0.93), and multidrug therapy (RR = 0.61, 95% CI = 0.60 to 0.62) would lower the risk of RCD. Furthermore, systematic research also reviewed seven risk factors associated with RCD in MCI. CONCLUSION: ApoE4, early onset, early appearance of extrapyramidal signs, high education level, and neuropsychiatric conditions might increase the risk of RCD while older age, diabetes, and multidrug therapy were the protective factors for AD.

Risk of Alzheimer's Disease in Obstructive Sleep Apnea Syndrome: Amyloid-β and Tau Imaging. - Elias, Alby; Cummins, Tia; Tyrrell, Regan; Lamb, Fiona; Doré, Vincent; Williams, Robert; Rosenfeld, J V; Hopwood, Malcolm; Villemagne, Victor L; Rowe, Christopher C (J Alzheimers Dis, 2018)
BACKGROUND: An association between obstructive sleep apnea (OSA) and Alzheimer's disease has been suggested but little is known about amyloid-β and tau deposition in this syndrome. OBJECTIVE: To determine amyloid and tau burden and cognitive function in OSA in comparison with those without a diagnosis of OSA. METHODS: The status of OSA was determined by asking participants about history of polysomnographic diagnosis of OSA and the use of Continuous Positive Airway Pressure (CPAP). A comprehensive neuropsychological battery measured cognitive function. Positron emission tomography (PET) was used to measure standardized uptake value ratio (SUVR) of 18F-florbetaben and 18F-AV1451, to quantify amyloid and tau burden. RESULTS: 119 male Vietnam veterans completed assessment. Impairment in visual attention and processing speed and increased body mass index (BMI) were seen in subjects with OSA compared with those without a diagnosis OSA. The cortical uptake of 18F-florbetaben was higher in the OSA group than in the control group (SUVR: 1.35±0.21 versus 1.27±0.16, p = 0.04). There were more apolipoprotein E ɛ4 allele (APOE ɛ4) carriers in the OSA group than in the control group. In multilinear regression analysis, the significance of OSA in predicting 18F-florbetaben uptake remained independent of age and vascular risk factors but not when BMI or APOE ɛ4 was adjusted. The reported use of CPAP (n = 14) had no effect on cognitive or amyloid PET findings. There was no significant difference in 18F-AV1451 uptake between the two groups. CONCLUSIONS: Obstructive sleep apnea is associated with Alzheimer's disease pathology, but this relationship is moderated by APOE ɛ4 and BMI.

Risk of Conversion to Dementia in a Mild Behavioral Impairment Group Compared to a Psychiatric Group and to a Mild Cognitive Impairment Group. - Taragano, Fernando E; Allegri, Ricardo F; Heisecke, Silvina L; Martelli, María I; Feldman, Mónica L; Sánchez, Viviana; García, Virginia A; Tufro, Graciela; Castro, Diego M; Leguizamón, Patricio Perez; Guelar, Verónica; Ruotolo, Eva; et al. (J Alzheimers Dis, 2018)
BACKGROUND: There is insufficient available information on behavioral changes in the absence of cognitive impairment as factors increasing the risk of conversion to dementia. OBJECTIVE: To observe and analyze patients with mild behavioral impairment (MBI), mild cognitive impairment (MCI), and a psychiatry group (PG) to compare the risk of progression to dementia. METHODS: From 677 initially assessed ≥60-year-old patients, a series of 348 patients was studied for a five-year period until censoring or conversion to dementia: 96 with MBI, 87 with MCI, and 165 with general psychiatry disorders, including 4 subgroups: Anxiety, Depression, Psychosis and Others. All patients were assessed with clinical, psychiatric, neurological, neuropsychological, and neuroimaging studies. RESULTS: From 348 patients, 126 evolved to dementia (36.2%). Conversion was significantly higher in MBI (71.5%), followed by the MCI-MBI overlap (59.6%) and MCI (37.8%) groups, compared to PG (13.9%) (Log-rank p < 0.001). MCI patients mostly converted to Alzheimer's dementia, while MBI converted to frontotemporal dementia and Lewy body dementia. Patients in PG converted to Lewy body dementia and frontotemporal dementia. CONCLUSION: Conversion to dementia is significantly higher in patients with neuropsychiatric symptoms. The MBI concept generates a new milestone in the refining of diagnosis of neurodegenerative diseases and the possibility of creating neuropsychiatric profiles. Its earlier identification will allow new possibilities for therapeutic intervention.

Role of Amyloid-β and Tau Proteins in Alzheimer's Disease: Confuting the Amyloid Cascade. - Gulisano, Walter; Maugeri, Daniele; Baltrons, Marian A; Fà, Mauro; Amato, Arianna; Palmeri, Agostino; D'Adamio, Luciano; Grassi, Claudio; Devanand, D P; Honig, Lawrence S; Puzzo, Daniela; Arancio, Ottavio (J Alzheimers Dis, 2018)
The "Amyloid Cascade Hypothesis" has dominated the Alzheimer's disease (AD) field in the last 25 years. It posits that the increase of amyloid-β (Aβ) is the key event in AD that triggers tau pathology followed by neuronal death and eventually, the disease. However, therapeutic approaches aimed at decreasing Aβ levels have so far failed, and tau-based clinical trials have not yet produced positive findings. This begs the question of whether the hypothesis is correct. Here we have examined literature on the role of Aβ and tau in synaptic dysfunction, memory loss, and seeding and spreading of AD, highlighting important parallelisms between the two proteins in all of these phenomena. We discuss novel findings showing binding of both Aβ and tau oligomers to amyloid-β protein precursor (AβPP), and the requirement for the presence of this protein for both Aβ and tau to enter neurons and induce abnormal synaptic function and memory. Most importantly, we propose a novel view of AD pathogenesis in which extracellular oligomers of Aβ and tau act in parallel and upstream of AβPP. Such a view will call for a reconsideration of therapeutic approaches directed against Aβ and tau, paving the way to an increased interest toward AβPP, both for understanding the pathogenesis of the disease and elaborating new therapeutic strategies.

Role of ASK1/p38 Cascade in a Mouse Model of Alzheimer's Disease and Brain Aging. - Hasegawa, Yu; Toyama, Kensuke; Uekawa, Ken; Ichijo, Hidenori; Kim-Mitsuyama, Shokei (J Alzheimers Dis, 2018)
To examine the role of ASK1 in Alzheimer's disease (AD), we generated 5XFAD mice deficient in ASK1 and investigated the characteristics of old 5XFAD and wild-type mice with ASK1 deficiency. ASK1 deficiency improved cognitive function in 24-month-old 5XFAD mice, which was associated with the reduction of phosphorylated p38. Thus, ASK1/p38 cascade seems to play some role in the pathogenesis of AD in mice. In 24-month-old wild-type mice, ASK1 deficiency increased cerebral vasoreactivity to acetazolamide and significantly reduced brain soluble Aβ, which were also associated with the reduction of phosphorylated p38. Thus, ASK1/p38 cascade may contribute to brain aging of wild-type mice. Collectively, our present results provided the evidence suggesting the involvement of ASK1/p38 cascade in AD and brain aging.
Keywords: Aging; Alzheimer Disease; Amyloid beta-Protein Precursor; Amyloid Precursor Protein Secretases; Animals; Aspartic Acid Endopeptidases; Avoidance Learning; Disease Models, Animal; Gene Expression Regulation; MAP Kinase Kinase Kinase 5; MAP Kinase Signaling System; Mice; Mice, Inbred C57BL; Mice, Transgenic; Presenilin-1; Reaction Time

Role of Blood-Brain Barrier in Alzheimer's Disease. - Cai, Zhiyou; Qiao, Pei-Feng; Wan, Cheng-Qun; Cai, Min; Zhou, Nan-Kai; Li, Qin (J Alzheimers Dis, 2018)
The blood-brain barrier (BBB) is involved in the pathogenesis of Alzheimer's disease (AD). BBB is a highly selective semipermeable structural and chemical barrier which ensures a stable internal environment of the brain and prevents foreign objects invading the brain tissue. BBB dysfunction induces the failure of Aβ transport from brain to the peripheral circulation across the BBB. Especially, decreased levels of LRP-1 (low density lipoprotein receptor-related protein 1) and increased levels of RAGE (receptor for advanced glycation endproducts) at the BBB can cause the failure of Aβ transport. The pathogenesis of AD is related to the BBB structural components, including pericytes, astrocytes, vascular endothelial cells, and tight junctions. BBB dysfunction will trigger neuroinflammation and oxidative stress, then enhance the activity of β-secretase and γ-secretase, and finally promote Aβ generation. A progressive accumulation of Aβ in brain and BBB dysfunction may become a feedback loop that gives rise to cognitive impairment and the onset of dementia. The correlation between BBB dysfunction and tau pathology has been well-reported. Therefore, regulating BBB function may be a new therapeutic target for treating AD.

The Role of Cognitive Reserve in Alzheimer's Disease and Aging: A Multi-Modal Imaging Review. - Menardi, Arianna; Pascual-Leone, Alvaro; Fried, Peter J; Santarnecchi, Emiliano (J Alzheimers Dis, 2018)
Comforts in modern society have generally been associated with longer survival rates, enabling individuals to reach advanced age as never before in history. With the increase in longevity, however, the incidence of neurodegenerative diseases, especially Alzheimer's disease, has also doubled. Nevertheless, most of the observed variance, in terms of time of clinical diagnosis and progression, often remains striking. Only recently, differences in the social, educational and occupational background of the individual, as proxies of cognitive reserve (CR), have been hypothesized to play a role in accounting for such discrepancies. CR is a well-established concept in literature; lots of studies have been conducted in trying to better understand its underlying neural substrates and associated biomarkers, resulting in an incredible amount of data being produced. Here, we aimed to summarize recent relevant published work addressing the issue, gathering evidence for the existence of a common path across research efforts that might ease future investigations by providing a general perspective on the actual state of the arts. An innovative model is hereby proposed, addressing the role of CR across structural and functional evidences, as well as the potential implementation of non-invasive brain stimulation techniques in the causal validation of such theoretical frame.

Role of Genetics and Epigenetics in the Pathogenesis of Alzheimer's Disease and Frontotemporal Dementia. - Fenoglio, Chiara; Scarpini, Elio; Serpente, Maria; Galimberti, Daniela (J Alzheimers Dis, 2018)
Alzheimer's disease (AD) and frontotemporal dementia (FTD) represent the first cause of dementia in senile and pre-senile population, respectively. A percentage of cases have a genetic cause, inherited with an autosomal dominant pattern of transmission. The majority of cases, however, derive from complex interactions between a number of genetic and environmental factors. Gene variants may act as risk or protective factors. Their combination with a variety of environmental exposures may result in increased susceptibility to these diseases or may influence their course. The scenario is even more complicated considering the effect of epigenetics, which encompasses mechanisms able to alter the expression of genes without altering the DNA sequence. In this review, an overview of the current genetic and epigenetic progresses in AD and FTD will be provided, with particular focus on 1) causative genes, 2) genetic risk factors and disease modifiers, and 3) epigenetics, including methylation, non-coding RNAs and chromatin remodeling.
Keywords: Alzheimer Disease; Animals; Epigenesis, Genetic; Frontotemporal Dementia; Genetic Predisposition to Disease; Humans

The Role of Lifestyle Factors and Sleep Duration for Late-Onset Dementia: A Cohort Study. - Larsson, Susanna C; Wolk, Alicja (J Alzheimers Dis, 2018)
BACKGROUND: The role of lifestyle factors and sleep for dementia is uncertain. OBJECTIVE: To examine the associations of major lifestyle factors and sleep duration with risk of late-onset dementia. METHODS: We used data from a population-based cohort of 28,775 Swedish adults who were ≥65 years of age and completed a questionnaire about lifestyle and other modifiable factors in the autumn of 1997. Dementia cases were ascertained by linkage with the Swedish National Patient Register. RESULTS: During a mean follow-up of 12.6 years, dementia was diagnosed among 3,755 participants (mean age at diagnosis 83.2±5.1 years). There were no associations of an overall healthy diet (defined by a modified Dietary Approaches to Stop Hypertension Diet score or a Mediterranean diet score), alcohol and coffee consumption, or physical activity with dementia incidence. Compared with never smokers, dementia risk was increased in former and current smokers (hazard ratio [95% confidence interval] = 1.13 [1.04-1.23] and 1.10 [1.00-1.21], respectively). Extended time of sleep (>9 h per night) was associated with an increased risk of dementia. However, this association appeared to be related to a reverse causation effect since the association did not remain after exclusion of cases diagnosed within the first five or ten years of follow-up. CONCLUSIONS: This study found no evidence that major lifestyle factors, aside from smoking, or sleep duration influence the risk of dementia.

Role of Neuroinflammation in the Trajectory of Alzheimer's Disease and in vivo Quantification Using PET. - Edison, Paul; Brooks, David J (J Alzheimers Dis, 2018)
Recent evidence suggests that neuroinflammation and immunity play a significant role in Alzheimer's disease and other neurodegenerative diseases. It has also been observed that, independent of the presence of aggregated proteins, neuroinflammation could be present in different neurodegenerative diseases. It has also been suggested that neuroinflammation could occur well ahead of amyloid deposition in AD. Recent genetic studies and other preclinical studies specifically point to a role of neuroinflammation and, in this review, we evaluate the evidence of neuroinflammation in the Alzheimer's disease trajectory and the different imaging modalities by which we could monitor neuroinflammation in vivo in humans.

Role of Noradrenergic Brain Nuclei in the Regulation of Carotid Artery Blood Flow: Pharmacological Evidence from Anesthetized Pigs with Alpha-2 Adrenergic Receptor Modulator Drugs. - Wirth, Klaus J (J Alzheimers Dis, 2018)
BACKGROUND: Cerebral hypoperfusion and degeneration of the noradrenergic locus coeruleus (LC) occur early in Alzheimer's disease (AD). Cerebral blood vessels are densely innervated by noradrenergic projections from the LC suggesting a functional role for the regulation of cerebral blood flow (CBF). Experimental LC stimulation, however, has provided no clarity as decreases or increases in CBF were reported from different experimental settings and investigators. OBJECTIVE: To find out with pharmacological methods whether endogenously released norepinephrine (NE) increases or decreases carotid artery blood flow (CABF) in anesthetized pigs by investigating the effect of centrally acting alpha-2 adrenergic drugs, which increase (atipamezole) or decrease (xylazine) NE in the brain. METHODS: CABF was measured by a Doppler-flow probe placed around the left carotid artery in pentobarbital anesthetized young pigs. RESULTS: Neither current antihypertensive drugs nor pharmacological stimulation of dopamine, histamine, serotonin or acetylcholine receptors changed CABF. The alpha-2 adrenergic-receptor agonist xylazine decreased, while the antagonist atipamezole raised CABF. This rise was abolished by a combined treatment with endothelial NO-synthase inhibitor Nω-Nitro-L-arginine methyl ester (L-NAME) and the non-selective β-receptor antagonist propranolol. Propranolol alone did not decrease CABF in contrast to L-NAME but decreased CABF after L-NAME, surprisingly. CONCLUSION: Pharmacological evidence suggests that NE released in the brain of anesthetized pigs raises CABF involving β-adrenergic mechanisms and nitric oxide. If in awake humans NE released from the LC had vasodilator effects early LC degeneration could be involved in early cerebral hypoperfusion of AD. Moreover, a cerebral adrenergic vascular innervation deficit, possibly resulting from LC degeneration, and systemic endothelial dysfunction together may act synergistically to reduce CBF.

Role of the Glyoxalase System in Alzheimer's Disease. - Jiang, Lianying; Wang, Jiafeng; Wang, Zhigang; Huang, Wenhui; Yang, Yixia; Cai, Zhiyou; Li, Keshen (J Alzheimers Dis, 2018)
Alzheimer's disease (AD) is an insidious and progressive neurodegenerative disease. The main pathological features of AD are the formation of amyloid-β deposits in the anterior cerebral cortex and hippocampus as well as the formation of intracellular neurofibrillary tangles. Thus far, accumulating evidence shows that glycation is closely related to AD. As a final product resulting from the crosslinking of a reducing sugar or other reactive carbonyls and a protein, the advanced glycation end products have been found to be associated with the formation of amyloid-β and neurofibrillary tangles in AD. As a saccharification inhibitor, the glyoxalase system and its substrate methylglyoxal (MG) were certified to be associated with AD onset and development. As an active substance of AGEs, MG could cause direct or indirect damage to nerve cells and tissues. MG is converted to D-lactic acid after decomposition by the glyoxalase system. Under normal circumstances, MG metabolism is in a dynamic equilibrium, whereas MG accumulates in cells in the case of aging or pathological states. Studies have shown that increasing glyoxalase activity and reducing the MG level can inhibit the generation of oxidative stress and AGEs, thereby alleviating the symptoms and signs of AD to some extent. This paper focuses on the relevant mechanisms of action of the glyoxalase system and MG in the pathogenesis of AD, as well as the potential of inhibiting the production of advanced glycation end products in the treatment of AD.

The Role of the Gut Microbiota in the Metabolism of Polyphenols as Characterized by Gnotobiotic Mice. - Pasinetti, Giulio Maria; Singh, Risham; Westfall, Susan; Herman, Francis; Faith, Jeremiah; Ho, Lap (J Alzheimers Dis, 2018)
A growing body of experimental data suggests that microbes in the gut influence behavior and can alter brain physiology and neurochemistry. Although promising, researchers are only starting to understand the potential of the gut microbiota for use in neurological disease. Recent evidence demonstrated that gastrointestinal activities are linked to mood disorders such as anxiety, depression, and most recently, cognitive functions in age-related neurodegenerative disorders. Studies from our group and others are uncovering new evidence suggesting that the gut microbiota plays a crucial role in the metabolism and bioavailability of certain dietary compounds and synthetic drugs. Based on this evidence, this review article will discuss the implications of the gut microbiota in mechanisms of bioavailability and biotransformation with an emphasis on dietary polyphenol compounds. This will be followed by a survey of ongoing innovative research identifying the ability of individual gut bacteria to enhance the bioavailability of gut-derived, brain-penetrating, bioactive polyphenol metabolites that ultimately influence mechanisms associated with the promotion of resilience against psychological and cognitive impairment in response to stress. Lastly, current research initiatives aimed at promoting the generation of brain bioactive polyphenol metabolites by specialized gut microbes will be discussed, specifically the use of gnotobiotic mice to develop bioengineered second generation probiotics. We propose that leveraging the gut microbial ecosystem to generate brain targeted bioactive metabolites from dietary polyphenols can attenuate lifestyle risk factors and promote resilience against age-related cognitive decline.

The Role of Verb Fluency in the Detection of Early Cognitive Impairment in Alzheimer's Disease. - Alegret, Montserrat; Peretó, Mar; Pérez, Alba; Valero, Sergi; Espinosa, Ana; Ortega, Gemma; Hernandez, Isabel; Mauleón, Ana; Rosende-Roca, Maitee; Vargas, Liliana; Rodríguez-Gómez, Octavio; Abdelnour, Carla; et al. (J Alzheimers Dis, 2018)
BACKGROUND: Verb fluency (VF) is the less commonly used fluency test, despite several studies suggesting its potential as a neuropsychological assessment tool. OBJECTIVE: To investigate the presence of VF deficits in mild cognitive impairment (MCI) and mild Alzheimer's disease (AD) dementia; to assess the usefulness of VF in the detection of cognitively healthy (CH) people who will convert to MCI, and from MCI to dementia; and to establish the VF cut-offs useful in the cognitive assessment of Spanish population. METHODS: 568 CH, 885 MCI, and 367 mild AD dementia individuals were administered the VF test and a complete neuropsychological battery. Longitudinal analyses were performed in 231 CH and 667 MCI subjects to search for VF predictors of diagnosis conversion. RESULTS: A worsening on VF performance from CH, MCI to AD dementia groups was found. Lower performances on VF were significantly related to conversion from CH to MCI/MCI to dementia. When the effect of time to conversion was analyzed, a significant effect of VF was found on the faster conversion from CH to MCI, but not from MCI to dementia. Moreover, VF cut-off scores and sensitivity/specificity values were calculated for 6 conditions (3 age ranges by 2 educational levels). CONCLUSION: The VF test may be a useful tool for the differential diagnosis of cognitive failure in the elderly. Since VF deficits seem to take place in early stages of the disease, it is a suitable neuropsychological tool for the detection not only of CH people who will convert to MCI, but also from MCI to dementia.
Keywords: Aged; Aged, 80 and over; Alzheimer Disease; Case-Control Studies; Cognitive Dysfunction; Cross-Sectional Studies; Early Diagnosis; Executive Function; Female; Humans; Language Tests; Logistic Models; Longitudinal Studies; Male; Middle Aged; Proportional Hazards Models; Sensitivity and Specificity; Spain

Roles of Mitochondrial 17β-Hydroxysteroid Dehydrogenase Type 10 in Alzheimer's Disease. - He, Xue-Ying; Isaacs, Charles; Yang, Song-Yu (J Alzheimers Dis, 2018)
17β-Hydroxysteroid dehydrogenase type 10 is a multifunctional, homotetrameric, mitochondrial protein encoded by the HSD17B10 gene at Xp 11.2. This protein, 17β-HSD10, is overexpressed in brain cells of Alzheimer's disease (AD) patients. It was reported to be involved in AD pathogenesis as the endoplasmic reticulum-associated amyloid-β binding protein (ERAB) and as amyloid-β binding alcohol dehydrogenase (ABAD). However, the exaggerated catalytic efficiencies for ERAB/ABAD in these reports necessitated the re-characterization of the catalytic functions of this brain enzyme. In addition to isoleucine metabolism, 17β-HSD10 is also responsible for the mitochondrial metabolism of neurosteroids such as 5α-androstane-3α,17β-diol and 17β-estradiol. These neurosteroids are inactivated by the oxidation catalyzed by 17β-HSD10. Since neurosteroid homeostasis is presumably essential for cognitive function, analysis of the impact of 17β-HSD10 and its inhibitor, amyloid-β peptide (Aβ), on the metabolism of neuroactive steroids offers a new approach to AD pathogenesis.
Keywords: 3-Hydroxyacyl CoA Dehydrogenases; Alzheimer Disease; Amyloid beta-Peptides; Brain; Endoplasmic Reticulum; Humans; Mitochondria; Neurotransmitter Agents; Oxidation-Reduction

S-[18F]THK-5117-PET and [11C]PIB-PET Imaging in Idiopathic Normal Pressure Hydrocephalus in Relation to Confirmed Amyloid-β Plaques and Tau in Brain Biopsies. - Leinonen, Ville; Rauramaa, Tuomas; Johansson, Jarkko; Bottelbergs, Astrid; Tesseur, Ina; van der Ark, Peter; Pemberton, Darrel; Koivisto, Anne M; Jääskeläinen, Juha E; Hiltunen, Mikko; Herukka, Sanna-Kaisa; Blennow, Kaj; et al. (J Alzheimers Dis, 2018)
BACKGROUND: Detection of pathological tau aggregates could facilitate clinical diagnosis of Alzheimer's disease (AD) and monitor drug effects in clinical trials. S-[18F]THK-5117 could be a potential tracer to detect pathological tau deposits in brain. However, no previous study have correlated S-[18F]THK-5117 uptake in PET with brain biopsy verified tau pathology in vivo. OBJECTIVE: Here we aim to evaluate the association between cerebrospinal fluid (CSF) AD biomarkers, S-[18F]THK-5117, and [11C]PIB PET against tau and amyloid lesions in brain biopsy. METHODS: Fourteen patients with idiopathic normal pressure hydrocephalus (iNPH) with previous shunt surgery including right frontal cortical brain biopsy and CSF Aβ1 - 42, total tau, and P-tau181 measures, underwent brain MRI, [11C]PIB PET, and S-[18F]THK-5117 PET imaging. RESULTS: Seven patients had amyloid-β (Aβ, 4G8) plaques, two both Aβ and phosphorylated tau (Pτ, AT8) and one only Pτ in biopsy. As expected, increased brain biopsy Aβ was well associated with higher [11C]PIB uptake in PET. However, S-[18F]THK-5117 uptake did not show any statistically significant correlation with either brain biopsy Pτ or CSF P-tau181 or total tau. CONCLUSIONS: S-[18F]THK-5117 lacked clear association with neuropathologically verified tau pathology in brain biopsy probably, at least partially, due to off-target binding. Further studies with larger samples of patients with different tau tracers are urgently needed. The detection of simultaneous Aβ and tau pathology in iNPH is important since that may indicate poorer and especially shorter response for CSF shunt surgery compared with no pathology.

Sally-Anne Test in Patients with Alzheimer's Disease Dementia. - Takenoshita, Shintaro; Terada, Seishi; Yokota, Osamu; Kutoku, Yumiko; Wakutani, Yosuke; Nakashima, Makoto; Maki, Yohko; Hattori, Hideyuki; Yamada, Norihito (J Alzheimers Dis, 2018)
Social cognition has recently been recognized as one of the essential cognitive domains. Some reports suggested that patients with Alzheimer's disease dementia (ADD) presented significant theory of mind deficits even in the mild condition. However, most previous studies included only small numbers of patients with ADD. The present study administered the first-order false belief (Sally-Anne) test to 116 consecutive patients with ADD from the outpatient units of the Memory Clinic and compared the characteristics of the two groups with correct and incorrect answers on the test. Then various clinical characteristics were evaluated. Only 37.1% of patients with ADD correctly answered the Sally-Anne test with the right explanation. Comparison between the two groups of correct and incorrect answers revealed a significant association between the frontal assessment battery score and the result of the Sally-Anne test in the multiple logistic regression analyses. Thus, patients with ADD presented a significant deficit in social cognition even in the mild condition. Frontal dysfunction was thought to be related to the deficits in mild ADD.
Keywords: Aged; Aged, 80 and over; Alzheimer Disease; Cognition Disorders; Disease Progression; Female; Humans; Logistic Models; Male; Neuropsychological Tests; Social Behavior Disorders; Theory of Mind

Secular Trends in Dementia Prevalence and Incidence Worldwide: A Systematic Review. - Stephan, Blossom C M; Birdi, Ratika; Tang, Eugene Yee Hing; Cosco, Theodore D; Donini, Lorenzo M; Licher, Silvan; Ikram, M Arfan; Siervo, Mario; Robinson, Louise (J Alzheimers Dis, 2018)
BACKGROUND: Time trends for dementia prevalence and incidence rates have been reported over the past seven decades in different countries and some have reported a decline. OBJECTIVE: To undertake a systematic review to critically appraise and provide an evidence-based summary of the magnitude and direction of the global changes in dementia prevalence and incidence across time. METHODS: Medline, EMBASE, and PsychINFO were searched for studies focused on secular trends in dementia prevalence and/or incidence until 18 December 2017. In total, 10,992 articles were identified and 43 retained. RESULTS: Overall, prevalence rates are largely increasing (evidence primarily from record-based surveys and cohort studies in Japan, Canada, and France) or have remained stable (evidence primarily from cohort studies in Sweden, Spain and China). A significant decline in prevalence has however been reported in more recent studies (i.e., from 2010 onwards) from Europe (e.g., UK and Sweden) and the USA. Incidence rates have generally remained stable or decreased in China, Canada, France, Germany, Denmark, Sweden, the Netherlands, UK, and USA. An increase has only been reported in five countries: Italy, Japan, Wales, Germany, and the Netherlands. Only one study reported findings (stability in incidence) from a low and middle-income country using data from Nigeria. CONCLUSIONS: The evidence on secular trends in the prevalence and incidence of dementia is mixed including contradictory findings using different (and in some cases the same) datasets in some countries (e.g., the USA, UK, and Sweden). This making it difficult to draw concrete conclusions. However, declining trends recently observed in some high-income Western countries in the most recent two decades including the UK, USA, and Sweden are encouraging. Updated dementia prevalence and incidence estimates will inform public health and financial planning as well as development of prevention strategies.

A Selection of Important Genes and Their Correlated Behavior in Alzheimer's Disease. - Cruz-Rivera, Yazeli E; Perez-Morales, Jaileene; Santiago, Yaritza M; Gonzalez, Valerie M; Morales, Luisa; Cabrera-Rios, Mauricio; Isaza, Clara E (J Alzheimers Dis, 2018)
In 2017, approximately 5 million Americans were living with Alzheimer's disease (AD), and it is estimated that by 2050 this number could increase to 16 million. In this study, we apply mathematical optimization to approach microarray analysis to detect differentially expressed genes and determine the most correlated structure among their expression changes. The analysis of GSE4757 microarray dataset, which compares expression between AD neurons without neurofibrillary tangles (controls) and with neurofibrillary tangles (cases), was casted as a multiple criteria optimization (MCO) problem. Through the analysis it was possible to determine a series of Pareto efficient frontiers to find the most differentially expressed genes, which are here proposed as potential AD biomarkers. The Traveling Sales Problem (TSP) model was used to find the cyclical path of maximal correlation between the expression changes among the genes deemed important from the previous stage. This leads to a structure capable of guiding biological exploration with enhanced precision and repeatability. Ten genes were selected (FTL, GFAP, HNRNPA3, COX1, ND2, ND3, ND4, NUCKS1, RPL41, and RPS10) and their most correlated cyclic structure was found in our analyses. The biological functions of their products were found to be linked to inflammation and neurodegenerative diseases and some of them had not been reported for AD before. The TSP path connects genes coding for mitochondrial electron transfer proteins. Some of these proteins are closely related to other electron transport proteins already reported as important for AD.

Self- and Informant-Reported Memory Complaints: Frequency and Severity in Cognitively Intact Individuals and those with Mild Cognitive Impairment and Neurodegenerative Dementias. - Rahman-Filipiak, Annalise M; Giordani, Bruno; Heidebrink, Judith; Bhaumik, Arijit; Hampstead, Benjamin M (J Alzheimers Dis, 2018)
BACKGROUND: Subjective memory complaints (SMCs) are incorporated into the diagnosis of mild cognitive impairment (MCI) and neurodegenerative dementias; however, the relative frequency of SMCs in cognitively intact older adults and those with different types of dementia is poorly understood. Similarly, the concordance between self- versus informant-reported SMCs has not been compared across different diagnostic groups. OBJECTIVE: This study aimed to evaluate the frequency of self-reported (Objective 1) and informant-reported (Objective 2) SMCs in cognitively intact adults or those diagnosed with MCI or a neurodegenerative dementia. Agreement between participant and informant complaints was also evaluated (Objective 3). METHODS: Baseline evaluation data were drawn from 488 participants (Mage = 70.49 years; Medu = 15.62 years) diagnosed as cognitively intact, non-amnestic MCI, amnestic single domain MCI, amnestic multi-domain MCI, possible/probable Alzheimer's disease, dementia with Lewy bodies, or frontotemporal dementia. Participants and their informants completed the Memory Assessment Clinic Questionnaire. RESULTS: One-way ANCOVAs controlling for age, education, and depression revealed no group differences in severity of self-reported SMCs. In contrast, informant memory ratings followed the expected clinical pattern, with comparable and most impaired ratings given to participants with any dementia diagnosis, followed by those with any MCI diagnosis, followed by cognitively intact participants. There was inconsistent agreement between self- and informant-reported SMC ratings in any of the impaired groups. CONCLUSIONS: Given greater diagnostic specificity and internal consistency of informant report, clinicians should weigh this information more heavily than self-report in the diagnostic process.

Self-Reported Physical Activity is Associated with Tau Burden Measured by Positron Emission Tomography. - Brown, Belinda M; Rainey-Smith, Stephanie R; Doré, Vincent; Peiffer, Jeremiah J; Burnham, Samantha C; Laws, Simon M; Taddei, Kevin; Ames, David; Masters, Colin L; Rowe, Christopher C; Martins, Ralph N; Villemagne, Victor L (J Alzheimers Dis, 2018)
Numerous animal studies have reported exercise reduces the accumulation of Alzheimer's disease pathology, including amyloid-β (Aβ) and tau. Furthermore, we previously reported a relationship between higher levels of physical activity (PA) and lower brain Aβ burden in a human population. The recent advent of tau positron emission tomography (PET) tracers enables us to extend our investigations into the evaluation of the relationship between PA and brain tau burden. Utilizing data from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study, we have examined the cross-sectional relationship between habitual PA and PET-quantified tau burden. Forty-three cognitively healthy older adults were categorized into low-moderate PA (LMPA; n = 16) or high PA (HPA; n = 27), based on self-reported PA levels. Tau PET imaging with the AV1451 tracer was conducted on all participants. The LMPA group had significantly higher neocortical tau burden (presented as a z-score; 1.22±1.98), compared to the HPA group (z-score: - 0.28±1.18). The difference between the LMPA and HPA groups was also evident when examining regional tau burden in the temporoparietal cortex and the prefrontal cortex. Our results suggest an association between self-reported PA level and brain tau burden. Future longitudinal and interventional studies utilizing larger samples sizes are vital to further investigate the nature of the relationship between tau and PA.

Separating Symptomatic Alzheimer's Disease from Depression based on Structural MRI. - Klöppel, Stefan; Kotschi, Maria; Peter, Jessica; Egger, Karl; Hausner, Lucrezia; Frölich, Lutz; Förster, Alex; Heimbach, Bernhard; Normann, Claus; Vach, Werner; Urbach, Horst; Abdulkadir, Ahmed (J Alzheimers Dis, 2018)
Older patients with depression or Alzheimer's disease (AD) at the stage of early dementia or mild cognitive impairment may present with objective cognitive impairment, although the pathology and thus therapy and prognosis differ substantially. In this study, we assessed the potential of an automated algorithm to categorize a test set of 65 T1-weighted structural magnetic resonance images (MRI). A convenience sample of elderly individuals fulfilling clinical criteria of either AD (n = 28) or moderate and severe depression (n = 37) was recruited from different settings to assess the potential of the pattern recognition method to assist in the differential diagnosis of AD versus depression. We found that our algorithm learned discriminative patterns in the subject's grey matter distribution reflected by an area under the receiver operator characteristics curve of up to 0.83 (confidence interval ranged from 0.67 to 0.92) and a balanced accuracy of 0.79 for the separation of depression from AD, evaluated by leave-one-out cross validation. The algorithm also identified consistent structural differences in a clinically more relevant scenario where the data used during training were independent from the data used for evaluation and, critically, which included five possible diagnoses (specifically AD, frontotemporal dementia, Lewy body dementia, depression, and healthy aging). While the output was insufficiently accurate to use it directly as a means for classification when multiple classes are possible, the continuous output computed by the machine learning algorithm differed between the two groups that were investigated. The automated analysis thus could complement, but not replace clinical assessments.

Serotonin Selective Reuptake Inhibitor Treatment Improves Cognition and Grey Matter Atrophy but not Amyloid Burden During Two-Year Follow-Up in Mild Cognitive Impairment and Alzheimer's Disease Patients with Depressive Symptoms. - Brendel, Matthias; Sauerbeck, Julia; Greven, Sonja; Kotz, Sebastian; Scheiwein, Franziska; Blautzik, Janusch; Delker, Andreas; Pogarell, Oliver; Ishii, Kazunari; Bartenstein, Peter; Rominger, Axel (J Alzheimers Dis, 2018)
Late-life depression, even when of subsyndromal severity, has shown strong associations with mild cognitive impairment (MCI) and Alzheimer's disease (AD). Preclinical studies have suggested that serotonin selective reuptake inhibitors (SSRIs) can attenuate amyloidogenesis. Therefore, we aimed to investigate the effect of SSRI medication on amyloidosis and grey matter volume in subsyndromal depressed subjects with MCI and AD during an interval of two years. 256 cognitively affected subjects (225 MCI/ 31 AD) undergoing [18F]-AV45-PET and MRI at baseline and 2-year follow-up were selected from the ADNI database. Subjects with a positive depression item (DEP(+); n = 73) in the Neuropsychiatric Inventory Questionnaire were subdivided to those receiving SSRI medication (SSRI(+); n = 24) and those without SSRI treatment (SSRI(-); n = 49). Longitudinal cognition (Δ-ADAS), amyloid deposition rate (standardized uptake value, using white matter as reference region (SUVRWM), and changes in grey matter volume were compared using common covariates. Analyses were performed separately in all subjects and in the subgroup of amyloid-positive subjects. Cognitive performance in DEP(+)/SSRI(+) subjects (Δ-ADAS: -5.0%) showed less deterioration with 2-year follow-up when compared to DEP(+)/SSRI(-) subjects (Δ-ADAS: +18.6%, p < 0.05), independent of amyloid SUVRWM at baseline. With SSRI treatment, the progression of grey matter atrophy was reduced (-0.9% versus -2.7%, p < 0.05), notably in fronto-temporal cortex. A slight trend towards lower amyloid deposition rate was observed in DEP(+)/SSRI(+) subjects versus DEP(+)/SSRI(-). Despite the lack of effect to amyloid PET, SSRI medication distinctly rescued the declining cognitive performance in cognitively affected patients with depressive symptoms, and likewise attenuated grey matter atrophy.

Serum Copper is not Altered in Frontotemporal Lobar Degeneration. - Squitti, Rosanna; Fostinelli, Silvia; Siotto, Mariacristina; Ferrari, Clarissa; Binetti, Giuliano; Benussi, Luisa; Rongioletti, Mauro; Ghidoni, Roberta (J Alzheimers Dis, 2018)
Meta-analyses show copper dyshomeostasis in Alzheimer's disease. However, a study evaluating copper changes in other neurodegenerative forms of dementia has not yet been performed. In this study, we assessed copper, ceruloplasmin, copper not bound to ceruloplasmin, and copper to ceruloplasmin ratio in 85 patients affected by frontotemporal lobar degeneration (FTLD) and 55 healthy controls. Data were analyzed through multivariate ANOVA models taking into account age and sex as covariates and the stratification for FTLD variants, after calculating power analysis to ensure the reliability of the conclusions drawn. The study revealed no difference between the groups.

Serum C-Peptide, Visfatin, Resistin, and Ghrelin are Altered in Sporadic and GRN-Associated Frontotemporal Lobar Degeneration. - Zanardini, Roberta; Benussi, Luisa; Fostinelli, Silvia; Saraceno, Claudia; Ciani, Miriam; Borroni, Barbara; Padovani, Alessandro; Binetti, Giuliano; Ghidoni, Roberta (J Alzheimers Dis, 2018)
Frontotemporal lobar degeneration (FTLD) is a group of complex neurodegenerative disease characterized by progressive deterioration of the frontal and anterior temporal lobes of the brain resulting in different heterogeneous conditions, mainly characterized by personality changes, behavioral disturbances, such as binge eating, and deficits in language and executive functions. Null mutations in progranulin gene (GRN) are one of the most frequent genetic determinants in familial frontotemporal dementia. Recently, progranulin was recognized as an adipokine involved in diet-induced obesity and insulin resistance revealing its metabolic function. Increasing evidence suggests that neurodegenerative dementias are associated with a higher prevalence of metabolic changes than in the general population. According to these findings, the aim of this study is to investigate putative alterations in markers linked to metabolic functions (i.e., C-peptide, ghrelin, glucose-dependent insulinotropic polypeptide, glucagon-like peptide-1, glucagon, insulin, resistin, and three adipokines as visfatin, leptin, and plasminogen activator inhibitor-1 total) in sporadic and GRN-related FTLD. We found that 1) C-peptide is increased in sporadic and GRN-mutated FTLD patients; in addition, we demonstrated an anticipation of the disease in patients with the highest C-peptide concentrations; 2) visfatin is slightly reduced in the whole FTLD group; 3) resistin, an adipokine involved in inflammatory-related diseases, is specifically increased in FTLD due to GRN null mutations; 4) ghrelin concentration is specifically increased in pre-symptomatic subjects and FTLD patients with GRN mutations. These findings support the hypothesis that alterations in metabolic pattern are involved in FTLD progression highlighting novel putative targets for the development of preventive and personalized therapies.
Keywords: Aged; Biomarkers; C-Peptide; Female; Frontotemporal Lobar Degeneration; Ghrelin; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Mutation; Nicotinamide Phosphoribosyltransferase; Progranulins; Resistin

Serum Non-Ceruloplasmin Non-Albumin Copper Elevation in Mild Cognitive Impairment and Dementia due to Alzheimer's Disease: A Case Control Study. - Rozzini, Luca; Lanfranchi, Francesco; Pilotto, Andrea; Catalani, Simona; Gilberti, Maria Enrica; Paganelli, Matteo; Apostoli, Pietro; Padovani, Alessandro (J Alzheimers Dis, 2018)
Several studies showed high serum copper levels in Alzheimer's disease (AD). The present study applied a newly developed method to detect serum copper free from proteins (free-Cu). Forty-four patients affected by dementia due to AD, thirty-six patients affected by mild cognitive impairment (MCI) due to AD, and twenty-eight healthy controls underwent clinical, cognitive, and MRI assessment. The new method showed higher free-Cu concentrations in MCI and dementia due to AD compared to controls (p < 0.0001). No correlation between copper levels, cognitive or MRI measures were found.
Keywords: Aged; Aged, 80 and over; Alzheimer Disease; Case-Control Studies; Cognitive Dysfunction; Copper; Female; Humans; Magnetic Resonance Imaging; Male; Psychiatric Status Rating Scales

Severe Agitation in Dementia: An Explorative Secondary Data Analysis on the Prevalence and Associated Factors in Nursing Home Residents. - Palm, Rebecca; Sorg, Christian G G; Ströbel, Armin; Gerritsen, Debby L; Holle, Bernhard (J Alzheimers Dis, 2018)
BACKGROUND: The phenomena of severe agitation is not well understood and often not adequately treated. OBJECTIVE: This article determines the prevalence and associated factors of severe agitation in nursing home residents with dementia. METHODS: Secondary data analysis within an observational study in German nursing homes with n = 1,967 participants. We assessed severity of agitation with the Neuropsychiatric Inventory Questionnaire (NPI-Q) and defined the construct of agitation as a composite score of the NPI-Q items agitation/aggression, disinhibition, and irritability/lability; the dependent variable of severe agitation was considered as being present in residents who scored 'severe' in at least one of these symptoms. A binary logistic regression model was calculated to estimate associations. RESULTS: The prevalence of severe agitation was 6.3% (n = 124). The strongest associations were found for elation/euphoria (OR 7.6, CI 3.1-18.5), delusions (OR 7.3, CI 4.0-13.2), apathy/indifference (OR 2.8, CI 1.7-4.7), anxiety (OR 2.2, CI 1.2-3.8), nighttime behaviors (OR 2.4, CI 1.4-4.2), motor disturbances (OR 2.4, CI 1.4-4.1), and male sex (OR 2.4. CI 1.3-4.2). CONCLUSION: Severe agitation in nursing home residents with dementia is a relevant clinical issue as approximately 70% of residents have a dementia. Residents with elation/euphoria and delusions may have a stronger risk of showing severe agitation. We consider delusions as a possible cause of agitation and therefore a prelude to agitation. Although it might be possible that elation/euphoria follows from agitation, we hypothesize that the residents first experience elation/ euphoria and exhibit agitation afterwards.

Severity-Related Increase and Cognitive Correlates of Serum VEGF Levels in Alzheimer's Disease ApoE4 Carriers. - Alvarez, X Anton; Alvarez, Irene; Aleixandre, Manuel; Linares, Carlos; Muresanu, Dafin; Winter, Stefan; Moessler, Herbert (J Alzheimers Dis, 2018)
Vascular endothelial growth factor (VEGF) is an angioneurin involved in the regulation of vascular and neural functions relevant for the pathophysiology of Alzheimer's disease (AD), but the influence of AD severity and ApoE4 status on circulating VEGF and its relationship with cognition has not been investigated. We assessed serum VEGF levels and cognitive performance in AD, amnestic mild cognitive impairment (MCI), and control subjects. VEGF levels were higher in AD patients than in MCI cases and controls (p < 0.05) and showed a progressive increase with clinical severity in the whole study population (p < 0.01). Among AD patients, severity-related VEGF elevations were significant in ApoE4 carriers (p < 0.05), but not in non-carriers. Increased VEGF levels were associated with disease severity and showed mild correlations with cognitive impairment that were only consistent for the ADAS-cog+ items remembering test instructions (memory) and maze task (executive functions) in the group of AD patients (p < 0.05). On the other hand, higher VEGF values were related to better memory and language performance in ApoE4 carriers with moderately-severe AD. According to these results showing severity- and ApoE4-related differences in serum VEGF and its cognitive correlates, it is suggested that increases in VEGF levels might represent an endogenous response driven by pathological factors and could entail cognitive benefits in AD patients, particularly in ApoE4 carriers. Our findings support the notion that VEGF constitutes a relevant molecular target to be further explored in AD pathology and therapy.

Sex Influences the Accuracy of Subjective Memory Complaint Reporting in Older Adults. - Sundermann, Erin E; Edmonds, Emily C; Delano-Wood, Lisa; Galasko, Douglas R; Salmon, David P; Rubin, Leah H; Bondi, Mark W (J Alzheimers Dis, 2018)
Subjective memory complaints (SMC) are required when diagnosing amnestic mild cognitive impairment (aMCI), although their relationship with objective memory performance and Alzheimer's disease (AD) pathology remains unclear. We investigated whether the sex of the patient/participant moderates these associations. Participants were 940 normal control (NC) and aMCI participants from the Alzheimer's Disease Neuroimaging Initiative. SMC were assessed via the memory scale of the Everyday Cognition questionnaire. Discrepancy scores were calculated between self- and informant-reports and categorized into "overestimates," "comparable estimates", and "underestimates" of SMC. We conducted linear and logistic regressions to examine the interaction of sex with self- and informant-reported SMC and discrepancy group on the Rey Auditory Verbal Learning Test (RAVLT) Immediate and Delayed Recall and on PET measures of amyloid-β (Aβ) positivity. Diagnosis-stratified analyses were also conducted. Overall, there were sex by self- and informant-reported SMC interactions for Immediate and Delayed Recall. Despite a higher proportion of "overestimates" in women, greater self- and informant-reported SMC showed a stronger relationship to poorer RAVLT scores in women versus men. Diagnosis-stratified analyses revealed that results were driven by aMCI participants. Conversely, overall, greater self- and informant-reported SMC related to greater odds of Aβ positivity regardless of sex. In diagnosis-stratified analyses, only informant-reported SMC related to Aβ positivity in aMCI. Relative to "comparable estimates," "underestimates" of SMC were associated with poorer RAVLT scores across sexes in the overall sample and in aMCI. The predictive utility of self-report SMC may be limited to women in aMCI. Sex differences should be considered when evaluating SMC.
Keywords: Aged; Cognitive Dysfunction; Female; Humans; Logistic Models; Male; Memory Disorders; Mental Recall; Neuropsychological Tests; Self Report; Sex Factors

Sex Moderates the Impact of Diagnosis and Amyloid PET Positivity on Hippocampal Subfield Volume. - Caldwell, Jessica Z K; Berg, Jody-Lynn; Shan, Guogen; Cummings, Jeffrey L; Banks, Sarah J (J Alzheimers Dis, 2018)
We examined moderation effects of sex and diagnosis on the effect of positive florbetapir positron emission tomography (PET) amyloid-β (Aβ) scan (A+) on hippocampus subfield volumes in 526 normal control (NC) and early mild cognitive impairment (eMCI) participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI2; ADNI-GO). Regression moderation models showed that women- but not men- with NC designation did not show reduced subiculum volumes despite A+. At the eMCI stage, A+ was detrimental across sexes. Findings were significant while accounting for the effects of age, cognition at screening, education, and APOE4 carrier status. These findings suggest that women with A+ have early neural resistance to Alzheimer's disease-related amyloid burden.

Sex-Dependent Differences in Spontaneous Autoimmunity in Adult 3xTg-AD Mice. - Kapadia, Minesh; Mian, M Firoz; Michalski, Bernadeta; Azam, Amber B; Ma, Donglai; Salwierz, Patrick; Christopher, Adam; Rosa, Elyse; Zovkic, Iva B; Forsythe, Paul; Fahnestock, Margaret; Sakic, Boris (J Alzheimers Dis, 2018)
The triple-transgenic (3xTg-AD) mouse strain is a valuable model of Alzheimer's disease (AD) because it develops both amyloid-β (Aβ) and tau brain pathology. However, 1-year-old 3xTg-AD males no longer show plaques and tangles, yet early in life they exhibit diverse signs of systemic autoimmunity. The current study aimed to address whether females, which exhibit more severe plaque/tangle pathology at 1 year of age, show similar autoimmune phenomena and if so, whether these immunological changes coincide with prodromal markers of AD pathology, markers of learning and memory formation, and epigenetic markers of neurodegenerative disease. Six-month-old 3xTg-AD and wild-type mice of both sexes were examined for T-cell phenotype (CD3+, CD8+, and CD4+ populations), serological measures (autoantibodies, hematocrit), soluble tau/phospho-tau and Aβ levels, brain-derived neurotrophic factor (BDNF) expression, and expression of histone H2A variants. Although no significant group differences were seen in tau/phospho-tau levels, 3xTg-AD mice had lower brain mass and showed increased levels of soluble Aβ and downregulation of BDNF expression in the cortex. Splenomegaly, depleted CD+ T-splenocytes, increased autoantibody levels and low hematocrit were more pronounced in 3xTg-AD males than in females. Diseased mice also failed to exhibit sex-specific changes in histone H2A variant expression shown by wild-type mice, implicating altered nucleosome composition in these immune differences. Our study reveals that the current 3xTg-AD model is characterized by systemic autoimmunity that is worse in males, as well as transcriptional changes in epigenetic factors of unknown origin. Given the previously observed lack of plaque/tangle pathology in 1-year-old males, an early, sex-dependent autoimmune mechanism that interferes with the formation and/or deposition of aggregated protein species is hypothesized. These results suggest that more attention should be given to studying sex-dependent differences in the immunological profiles of human patients.

Sex-Related Reserve Hypothesis in Alzheimer's Disease: Changes in Cortical Thickness with a Five-Year Longitudinal Follow-Up. - Lee, Juyoun; Cho, Hanna; Jeon, Seun; Kim, Hee Jin; Kim, Yeo Jin; Lee, Jeongmin; Kim, Sung Tae; Lee, Jong-Min; Chin, Juhee; Lockhart, Samuel N; Lee, Ae Young; Na, Duk L; et al. (J Alzheimers Dis, 2018)
BACKGROUND: Sex effects on the progression of Alzheimer's disease (AD) have received less attention than other demographic factors, including onset age and education. OBJECTIVE: The aim of this study was to investigate whether sex affected cortical thinning in the disease progression of AD. METHODS: We prospectively recruited 36 patients with early-stage AD and 14 people with normal cognition. All subjects were assessed with magnetic resonance imaging at baseline, Year 1, Year 3, and Year 5. We performed cortical thickness analyses using surface-based morphometry on magnetic resonance imaging. RESULTS: Women with AD showed more rapid cortical thinning in the left dorsolateral frontal cortex, left superior temporal gyrus, bilateral temporo-parietal association cortices, bilateral anterior cingulate gyri, bilateral medial frontal cortices, and bilateral occipital cortices over 5 years than men with AD, even though there was no difference in cortical thickness at baseline. In contrast, there were no regions of significantly more rapid atrophy in men with AD. CONCLUSIONS: Our findings suggest that women deteriorate faster than men in the progression of AD.

Shear-Induced Amyloid Formation in the Brain: III. The Roles of Shear Energy and Seeding in a Proposed Shear Model. - Trumbore, Conrad N (J Alzheimers Dis, 2018)
If cerebrospinal and interstitial fluids move through very narrow brain flow channels, these restrictive surroundings generate varying levels of fluid shear and different shear rates, and dissolved amyloid monomers absorb different shear energies. It is proposed that dissolved amyloid-β protein (Aβ) and other amyloid monomers undergo shear-induced conformational changes that ultimately lead to amyloid monomer aggregation even at very low brain flow and shear rates. Soluble Aβ oligomers taken from diseased brains initiate in vivo amyloid formation in non-diseased brains. The brain environment is apparently responsible for this result. A mechanism involving extensional shear is proposed for the formation of a seed Aβ monomer molecule that ultimately promotes templated conformational change of other Aβ molecules. Under non-quiescent, non-equilibrium conditions, gentle extensional shear within the brain parenchyma, and perhaps even during laboratory preparation of Aβ samples, may be sufficient to cause subtle conformational changes in these monomers. These result from brain processes that significantly lower the high activation energy predicted for the quiescent Aβ dimerization process. It is further suggested that changes in brain location and changes brought about by aging expose Aβ molecules to different shear rates, total shear, and types of shear, resulting in different conformational changes in these molecules. The consequences of such changes caused by variable shear energy are proposed to underlie formation of amyloid strains causing different amyloid diseases. Amyloid researchers are urged to undertake studies with amyloids, anti-amyloid drugs, and antibodies while all of these are under shear conditions similar to those in the brain.

Shear-Induced Amyloid Formation in the Brain: IV. Effects on Synapses Surrounding Senile Plaque and in Plaque-Free Regions. - Trumbore, Conrad N (J Alzheimers Dis, 2018)
Amyloid-β oligomers (AβO) have been proposed as neurotoxins in the synaptic dysfunction that precedes Alzheimer's disease symptoms. Human and animal model studies report that senile plaques contain a halo of AβO molecules surrounding these plaques. A far smaller number of oligomers are distributed widely in plaque-free regions. It has been suggested that oligomers migrate from halos to nearby synapses and are incorporated into both pre- and postsynaptic terminals. These two types of oligomers have two different toxicities when extracted and injected in animal models. This paper proposes a shear-energy based explanation for the data in these studies. Shear hypotheses in the preceding three papers in this series are applied to suggest how the hydrodynamics and resulting shear patterns explain the spatial distribution of both AβO types, the apparent synapse loss in the vicinity of plaque particles, and possible reasons for the differing toxicities. A shear-based mechanism is proposed for the preferential migration of locally shear-excited Aβ molecules into the synaptic cleft. It is proposed that high energy laminar shear generated by the forced diversion of interstitial fluid around the flow-impeding plaque particle is responsible for the formation of AβOs around the plaque. It is suggested that in plaque-free regions, a different type of AβO with different toxicity is generated by lower energy shear flow around synapses, depositing AβO within the synapse from either the neuron membrane surface or by prion-like seeding within the synaptic cleft by locally-sheared Aβ molecules near the synapse entry.

Short-Term Effects of Microglia-Specific Mitochondrial Dysfunction on Amyloidosis in Transgenic Models of Alzheimer's Disease. - Steffen, Johannes; Stenzel, Jan; Ibrahim, Saleh; Pahnke, Jens (J Alzheimers Dis, 2018)
Reduction of mitochondrial activity is a subtle and early event in the pathogenesis of Alzheimer's disease. Mitochondrial damage and consequentially enhanced production of reactive oxygen species is particularly occurring in the vicinity of amyloid plaques. Since all cells are affected by mitochondrial damage, analyses of cell type-specific effects are challenging. To study the impact of mitochondrial alterations on microglial activity in a homogeneous genetic background, we generated bone marrow chimeras of irradiated 46-days-old APP-transgenic mice. For reconstitution, bone marrow from CX3CR1-eGFP mice with mitochondria of either non-obese diabetic or C57BL/6J animals was utilized. Successful reconstitution was evident in 100-day-old animals, by the presence of eGFP-positive cells in liver and spleen. In the brain, one-third of IBA1-positive microglia cells were newly recruited eGFP-expressing cells. Although donor-derived microglia were equally located in the proximity of amyloid plaques, no difference was observed in either the amyloid level, total number, or microglial coverage of plaques. These results indicate that during this brief and early phase of amyloid deposition, beneficial mitochondrial alterations in the newly recruited third of microglial cells were not sufficient to affect the amyloidosis in APP-transgenic mice.

Simultaneous Aerobic Exercise and Memory Training Program in Older Adults with Subjective Memory Impairments. - McEwen, Sarah C; Siddarth, Prabha; Abedelsater, Berna; Kim, Yena; Mui, Wenli; Wu, Pauline; Emerson, Natacha D; Lee, Jacob; Greenberg, Shayna; Shelton, Tiffany; Kaiser, Scott; Small, Gary W; et al. (J Alzheimers Dis, 2018)
BACKGROUND: Several modifiable lifestyle factors have been shown to have potential beneficial effects in slowing cognitive decline. Two such factors that may affect cognitive performance and slow the progression of memory loss into dementia in older adults are cognitive training and physical activity. There are currently no effective treatments for dementia; therefore, preventative strategies to delay or prevent the onset of dementia are of critical importance. OBJECTIVE: The aim of this study was to determine the relative effectiveness of simultaneous performance of memory training and aerobic exercise to a sequential performance intervention on memory functioning in older adults. METHODS: 55 older adults (aged 60- 75) with subjective memory impairments (non-demented and non-MCI) completed the intervention that consisted of 90-minute small group classes held twice weekly. Participants were randomized to either 4-weeks of supervised strategy-based memory training done simultaneously while stationary cycling (SIM) or sequentially after the stationary cycling (SEQ). Standardized neurocognitive measures of memory, executive functioning, speed of processing, attention, and cognitive flexibility were assessed at baseline and post-intervention. RESULTS: The SIM group, but not the SEQ group, had a significant improvement on composite memory following the intervention (t(51) = 2.7, p = 0.01, effect size (ES) = 0.42) and transfer to non-trained reasoning abilities (t(51) = 6.0, ES = 0.49) and complex attention (t(51) = 3.1, p = 0.003, ES = 0.70). Conversely, the SEQ group, but not the SIM, showed significant improvement in executive functioning (t(51) = 5.0, p = 0.0001, ES = 0.96). CONCLUSION: These findings indicate that a 4-week simultaneous memory training and aerobic exercise program is sufficient to improve memory, attention, and reasoning abilities in older adults.
Keywords: Aged; Attention; California; Cognition; Executive Function; Exercise; Female; Humans; Learning; Male; Memory; Memory Disorders; Middle Aged; Treatment Outcome

Single Subject Classification of Alzheimer's Disease and Behavioral Variant Frontotemporal Dementia Using Anatomical, Diffusion Tensor, and Resting-State Functional Magnetic Resonance Imaging. - Bouts, Mark J R J; Möller, Christiane; Hafkemeijer, Anne; van Swieten, John C; Dopper, Elise; van der Flier, Wiesje M; Vrenken, Hugo; Wink, Alle Meije; Pijnenburg, Yolande A L; Scheltens, Philip; Barkhof, Frederik; Schouten, Tijn M; et al. (J Alzheimers Dis, 2018)
BACKGROUND/OBJECTIVE: Overlapping clinical symptoms often complicate differential diagnosis between patients with Alzheimer's disease (AD) and behavioral variant frontotemporal dementia (bvFTD). Magnetic resonance imaging (MRI) reveals disease specific structural and functional differences that aid in differentiating AD from bvFTD patients. However, the benefit of combining structural and functional connectivity measures to-on a subject-basis-differentiate these dementia-types is not yet known. METHODS: Anatomical, diffusion tensor (DTI), and resting-state functional MRI (rs-fMRI) of 30 patients with early stage AD, 23 with bvFTD, and 35 control subjects were collected and used to calculate measures of structural and functional tissue status. All measures were used separately or selectively combined as predictors for training an elastic net regression classifier. Each classifier's ability to accurately distinguish dementia-types was quantified by calculating the area under the receiver operating characteristic curves (AUC). RESULTS: Highest AUC values for AD and bvFTD discrimination were obtained when mean diffusivity, full correlations between rs-fMRI-derived independent components, and fractional anisotropy (FA) were combined (0.811). Similarly, combining gray matter density (GMD), FA, and rs-fMRI correlations resulted in highest AUC of 0.922 for control and bvFTD classifications. This, however, was not observed for control and AD differentiations. Classifications with GMD (0.940) and a GMD and DTI combination (0.941) resulted in similar AUC values (p = 0.41). CONCLUSION: Combining functional and structural connectivity measures improve dementia-type differentiations and may contribute to more accurate and substantiated differential diagnosis of AD and bvFTD patients. Imaging protocols for differential diagnosis may benefit from also including DTI and rs-fMRI.

SIRT1 Deacetylates SC35 and Suppresses Its Function in Tau Exon 10 Inclusion. - Yin, Xiaomin; Jiang, Xiaosu; Wang, Jia; Qian, Shuo; Liu, Fei; Qian, Wei (J Alzheimers Dis, 2018)
Approximately equal amounts of 3R-tau and 4R-tau resulting from alternative splicing of tau exon 10 is necessary to maintain normal brain function. Dysregulation of alternative splicing of tau exon 10 and the imbalance of 3R-tau/4R-tau have been seen in inherited and sporadic tauopathies. Splicing factor SC35 (also name as SRSF2) plays an important role in promoting tau exon 10 inclusion. SC35 is post-translationally modified by phosphorylation and acetylation, but the role of acetylation in SC35-medicated tau exon 10 inclusion is unknown. Sirtuin type 1 (SIRT1) is an enzyme that deacetylates proteins and associates with age-related disease such as Alzheimer's disease. In the present study, we determined the role of SIRT1 in SC35 acetylation and in the alternative splicing of tau exon 10. We found that SIRT1 interacts with and deacetylates SC35, and inhibits SC35-promoted tau exon 10 inclusion. Substituting K52 residue of SC35 by arginine impairs the role of SC35 in tau exon 10 inclusion. These results suggest that SIRT1 may serve as a therapeutic target for tauopathy by regulating SC35-mediated tau exon 10 splicing.
Keywords: Alternative Splicing; Alzheimer Disease; Exons; HEK293 Cells; HeLa Cells; Humans; Phosphorylation; Ribonucleoproteins; Serine-Arginine Splicing Factors; Sirtuin 1; tau Proteins; Tauopathies

Sleep and EEG Power Spectral Analysis in Three Transgenic Mouse Models of Alzheimer's Disease: APP/PS1, 3xTgAD, and Tg2576. - Kent, Brianne A; Strittmatter, Stephen M; Nygaard, Haakon B (J Alzheimers Dis, 2018)
BACKGROUND: Sleep disturbances have long been associated with Alzheimer's disease (AD), and there is a growing interest in how these disturbances might impact AD pathophysiology. Despite this growing interest, surprisingly little is known about how sleep architecture and the broader neuronal network are affected in widely used transgenic mouse models of AD. OBJECTIVE: We analyzed sleep and electroencephalography (EEG) power in three transgenic mouse models of AD, using identical and commercially available hardware and analytical software. The goal was to assess the suitability of these mouse lines to model sleep and the broader neuronal network dysfunction measured by EEG in AD. METHODS: Tg2576, APP/PS1, and 3xTgAD transgenic AD mice were studied using in vivo EEG recordings for sleep/wake time and power spectral analysis. RESULTS: Both the APP/PS1 model at 8- 10 months and the Tg2576 model at 12 months of age exhibited stage-dependent decreases in theta and delta power, and shifts in the power spectra toward higher frequencies. Stage-dependent power spectral analyses showed no changes in the 3xTgAD model at 18 months of age. The percentage of time spent awake, in non-rapid eye movement sleep (NREM), or in rapid-eye-movement sleep (REM) was not different between genotypes in any of the transgenic lines. CONCLUSION: Our findings are consistent with data from several other transgenic AD models as well as certain studies in patients with mild cognitive impairment. Further studies will be needed to better understand the correlation between EEG spectra and AD pathophysiology, both in AD models and the human condition.

A Small Molecule Inhibitor of Plasminogen Activator Inhibitor-1 Reduces Brain Amyloid-β Load and Improves Memory in an Animal Model of Alzheimer's Disease. - Akhter, Hasina; Huang, Wen-Tan; van Groen, Thomas; Kuo, Hui-Chien; Miyata, Toshio; Liu, Rui-Ming (J Alzheimers Dis, 2018)
Alzheimer's disease (AD) is a major cause of dementia in the elderly with no effective treatment. Accumulation of amyloid-β peptide (Aβ) in the brain is a pathological hallmark of AD and is believed to be a central disease-causing and disease-promoting event. In a previous study, we showed that deletion of plasminogen activator inhibitor 1 (PAI-1), a primary inhibitor of tissue type and urokinase type plasminogen activators (tPA and uPA), significantly reduced brain Aβ load in APP/PS1 mice, an animal model of familial AD. In this study, we further show that oral administration of TM5275, a small molecule inhibitor of PAI-1, for a period of 6 weeks, inhibits the activity of PAI-1 and increases the activities of tPA and uPA as well as plasmin, which is associated with a reduction of Aβ load in the hippocampus and cortex and improvement of learning/memory function in APP/PS1 mice. Protein abundance of low density lipoprotein related protein-1 (LRP-1), a multi ligand endocytotic receptor involved in transporting Aβ out of the brain, as well as plasma Aβ42 are increased, whereas the expression and processing of full-length amyloid-β protein precursor is not affected by TM5275 treatment in APP/PS1 mice. In vitro studies further show that PAI-1 increases, whereas TM5275 reduces, Aβ40 level in the culture medium of SHSY5Y-APP neuroblastoma cells. Collectively, our data suggest that TM5275 improves memory function of APP/PS1 mice, probably by reducing brain Aβ accumulation through increasing plasmin-mediated degradation and LRP-1-mediated efflux of Aβ in the brain.

Small Vessel Cerebrovascular Pathology Identified by Magnetic Resonance Imaging Is Prevalent in Alzheimer's Disease and Mild Cognitive Impairment: A Potential Target for Intervention. - Scott, Tammy M; Bhadelia, Rafeeque A; Qiu, Wei Qiao; Folstein, Marshal F; Rosenberg, Irwin H (J Alzheimers Dis, 2018)
BACKGROUND: There is evidence that Alzheimer's disease (AD) has significant cerebrovascular etiopathogenesis. Understanding potentially modifiable risk factors for vascular disease can help design long-term intervention strategies for controlling or preventing cognitive dysfunction attributable to cerebrovascular disease. OBJECTIVE: To evaluate the presence and severity of markers of cerebrovascular pathology, its relationship to diagnostic categories of dementia, including AD, and association with the metabolic biomarker homocysteine. METHODS: In a cross-sectional observational study, 340 community-dwelling elders received a clinical evaluation including brain MRI and neuropsychological tests. Dementia and mild cognitive impairment (MCI) were diagnosed by consensus committee. Fasting total plasma homocysteine was measured. Statistical analyses were adjusted for demographics and cerebrovascular risk factors. RESULTS: Nearly 25% of those diagnosed with AD had small vessel infarcts (SVI). Periventricular white matter hyperintensity (pvWMHI) was prevalent in participants with AD (61%) or MCI (amnesic 61% and non-amnesic 54%, respectively). Participants with SVI and/or pvWMHI also had greater brain atrophy. Homocysteine concentrations were higher in individuals with cerebrovascular findings than in those without. In individuals with cerebrovascular disease, homocysteine was inversely related to executive function (p = 0.022) and directly related to degree of brain atrophy (p = 0.009). CONCLUSIONS: We demonstrated a significant prevalence of small vessel markers of cerebrovascular pathology in individuals diagnosed with AD, with a significant concurrence between cerebrovascular disease and brain and ventricular atrophy. While current research on AD has focused on amyloid-βpeptide deposition, tau-pathology, and microglial activation and inflammation, greater attention to the cerebrovascular contribution to this neurodegenerative disease presents an additional target for therapeutic prevention and intervention.

Social Dysfunction in Older Age and Relationships with Cognition, Depression, and Apathy: The GreatAGE Study. - Lozupone, Madia; Panza, Francesco; Piccininni, Marco; Copetti, Massimiliano; Sardone, Rodolfo; Imbimbo, Bruno P; Stella, Eleonora; D'Urso, Francesca; Barulli, Maria Rosaria; Battista, Petronilla; Grasso, Alessandra; Tortelli, Rosanna; et al. (J Alzheimers Dis, 2018)
BACKGROUND: Most studies focused on only one measure of social dysfunction in older age, without proper validation and distinction across different dimensions including subjectivity, structural, and functional aspects. OBJECTIVE: We sought to validate the Social Dysfunction Rating Scale (SDRS) and its factorial structure, also determining the association of SDRS with cognitive functions, global psychopathology, and social deprivation. METHODS: The SDRS was administered to 484 Italian community-dwelling elderly, recruited in the GreatAGE study, a population-based study on aging conducted in Castellana Grotte, Bari, Southern Italy. We determined objective and subjective psychometric properties of SDRS against the gold standard evaluation of social dysfunction according to the Semi-structured Clinical Diagnostic Interview for DSM-IV-TR Axis I Disorders (SCID-I) criterion. RESULTS: The SDRS showed a moderate accuracy with an optimal cut-off of 26 maximized with higher sensitivity (0.74,95% CI:0.63-0.84) than specificity (0.57,95% CI:0.50-0.64). A five-factor structure was carried out and five dimensions of SDRS were identified (loneliness; social isolation; feeling of contribution/uselessness; lack of leisure activities; anxiety for the health). Education and global cognitive functions were inversely correlated to SDRS, while a direct association with global psychopathology, depression, and apathy was found. The prevalence of higher SDRS scores was major in subjects with current psychiatric disorders versus other subjects.∥Conclusion: The SDRS could be a valid instrument to capture both size and quality of social dysfunction, both in subjects with psychiatric disorders and in normal subjects. Several categories of social dysfunction differed only in the degree of health deprivation, not in social or material deprivation.

Some Methodological Characteristics of Alzheimer-Associated Urine Neuronal Thread Protein Detected by Enzyme-Linked Immunosorbent Assay. - Jin, He; Wang, Rong; Liu, Zhaohui; Jia, Qiang; Wu, Yanchuan; Zhao, Zhiwei; Wang, Yulan; Zhang, Xu (J Alzheimers Dis, 2018)
BACKGROUND: Alzheimer-associated neuronal thread protein (AD7c-NTP) has been found to be a candidate biomarker of Alzheimer's disease (AD). OBJECTIVE: To investigate the effects of urine collected time, different preservatives addition, and storage condition on the measurement of urine AD7c-NTP by enzyme-linked immunosorbent assay (ELISA). METHODS: Three hundred urine samples were collected from 20 participants at three time points on five consecutive days. These samples were immediately placed at 4°C and detected within 2 h. The single spot samples of the first day morning were split into eleven duplicate aliquots (a-k) of 1 ml each, (a) without any preservative (untreated), (b) containing boric acid (2 g/L), (c) containing NaHCO3 (5 g/L), (a-c) were detected at six different time points. For the other eight preservative-free samples, (d-g) were stored at -20°C and (h-k) were stored at -70°C, respectively, detected at different time points. All of the results were compared with the baseline urine. RESULTS: The urine AD7c-NTP levels at different time points behaved stably (p > 0.05). Urine samples without any preservative increased over time, and compared with the NaHCO3 addition group, boric acid addition group behaved stably. Samples stored at -20°C and -70°C led to an obviously false positive. CONCLUSIONS: AD7c-NTP can be tested using random urine instead of the first morning urine. If the specimen cannot be tested in time, boric acid appears to be an acceptable preservative with storage at 4°C, freezing is not recommended.

SORL1 Variants in Familial Alzheimer's Disease. - Gómez-Tortosa, Estrella; Ruggiero, María; Sainz, Ma José; Villarejo-Galende, Alberto; Prieto-Jurczynska, Cristina; Venegas Pérez, Begoña; Ordás, Carlos; Agüero, Pablo; Guerrero-López, Rosa; Pérez-Pérez, Julián (J Alzheimers Dis, 2018)
The SORL1 gene encodes a protein involved in the amyloidogenic process, and its variants have been associated with Alzheimer's disease (AD) physiopathology. We screened for SORL1 variants in 124 familial (44 early- and 80 late-onset) dementia of Alzheimer type (DAT) cases. Nine potentially pathogenic changes (three not previously reported and six rare variants) were found in nine probands (7%). After screening the control population and siblings (presence in at least 1/200 controls and/or absence of segregation pattern), a causal relationship with the disease was considered unlikely in six variants and uncertain in one. The change Trp848Ter and a splice-site variant remained likely correlated with the disease. SORL1 mutations are present in 7% of our familial DAT cohort, though in most cases cannot be considered the direct cause of the disease.
Keywords: Aged; Alzheimer Disease; Case-Control Studies; Female; Gene Frequency; Genetic Predisposition to Disease; Humans; LDL-Receptor Related Proteins; Male; Membrane Transport Proteins; Middle Aged; Mutation; Polymorphism, Single Nucleotide; Siblings; Spain

SPARCL1 Accelerates Symptom Onset in Alzheimer's Disease and Influences Brain Structure and Function During Aging. - Seddighi, Sahba; Varma, Vijay R; An, Yang; Varma, Sudhir; Beason-Held, Lori L; Tanaka, Toshiko; Kitner-Triolo, Melissa H; Kraut, Michael A; Davatzikos, Christos; Thambisetty, Madhav (J Alzheimers Dis, 2018)
We recently reported that alpha-2 macroglobulin (A2M) is a biomarker of neuronal injury in Alzheimer's disease (AD) and identified a network of nine genes co-expressed with A2M in the brain. This network includes the gene encoding SPARCL1, a protein implicated in synaptic maintenance. Here, we examine whether SPARCL1 is associated with longitudinal changes in brain structure and function in older individuals at risk for AD in the Baltimore Longitudinal Study of Aging. Using data from the Gene-Tissue Expression Project, we first identified two single nucleotide polymorphisms (SNPs), rs9998212 and rs7695558, associated with lower brain SPARCL1 gene expression. We then analyzed longitudinal trajectories of cognitive performance in 591 participants who remained cognitively normal (average follow-up interval: 11.8 years) and 129 subjects who eventually developed MCI or AD (average follow-up interval: 9.4 years). Cognitively normal minor allele carriers of rs7695558 who developed incident AD showed accelerated memory loss prior to disease onset. Next, we compared longitudinal changes in brain volumes (MRI; n = 120 participants; follow-up = 6.4 years; 826 scans) and resting-state cerebral blood flow (rCBF; 15O-water PET; n = 81 participants; follow-up = 7.7 years; 664 scans) in cognitively normal participants. Cognitively normal minor allele carriers of rs9998212 showed accelerated atrophy in several global, lobar, and regional brain volumes. Minor allele carriers of both SNPs showed longitudinal changes in rCBF in several brain regions, including those vulnerable to AD pathology. Our findings suggest that SPARCL1 accelerates AD pathogenesis and thus link neuroinflammation with widespread changes in brain structure and function during aging.
Keywords: Aged; Aged, 80 and over; Aging; Alzheimer Disease; Brain; Calcium-Binding Proteins; Cerebrovascular Circulation; Cognition Disorders; Extracellular Matrix Proteins; Female; Humans; Independent Living; Longitudinal Studies; Magnetic Resonance Imaging; Male; Middle Aged; Neuropsychological Tests; Polymorphism, Single Nucleotide; Positron-Emission Tomography

Spatial Navigation in the Elderly with Alzheimer's Disease: A Cross-Sectional Study. - Zanco, Marcos; Plácido, Jessica; Marinho, Valeska; Ferreira, José Vinicius; de Oliveira, Felipe; Monteiro-Junior, Renato; Barca, Maria; Engedal, Knut; Laks, Jerson; Deslandes, Andrea (J Alzheimers Dis, 2018)
BACKGROUND: Spatial navigation is a fundamental cognitive ability that allows an individual to maintain independence by facilitating the safe movement from one place to another. It emerges as one of the first deficits in patients with Alzheimer's disease (AD). OBJECTIVE: To compare spatial navigation performance in the healthy elderly and AD patients through use of the Floor Maze Test (FMT)- an easy-to-apply two-dimensional (2D) maze- and determine which cognitive and functional capacities were associated with performance in this task. METHODS: The FMT was administered to 24 AD patients and 36 healthy controls. Spatial navigation was evaluated through the FMT. Functional capacity was evaluated through the Senior Fitness Test battery of tests. Cognitive functions were evaluated through the Mini-Mental State Examination (MMSE), verbal fluency, digit span test, and the Rey Auditory Verbal Learning Test (RAVLT). RESULTS: The group with AD was significantly slower and presented more errors at all stages of the FMT. Planning Time (PT) performance was associated with cardiorespiratory resistance (Step test) and delayed memory according to the RAVLT (R2 = 0.395, p < 0.001). Performance in the Immediate Maze Time (IMT) and Delayed Maze Time (DMT) was associated with global cognitive status (MMSE) (R2 = 0.509) and delayed memory (R2 = 0.540). CONCLUSION: Patients with AD present significant spatial navigation deficits. Their performance on the FMT is influenced by cardiorespiratory capacity, memory, and global cognitive function. As exercise helps to improve executive function and functional capacity, future intervention studies should be carried out to analyze the possible effects of physical exercise on spatial navigation.

Stabilized Low-n Amyloid-β Oligomers Induce Robust Novel Object Recognition Deficits Associated with Inflammatory, Synaptic, and GABAergic Dysfunction in the Rat. - Watremez, William; Jackson, Joshua; Almari, Bushra; McLean, Samantha L; Grayson, Ben; Neill, Joanna C; Fischer, Nicolas; Allouche, Ahmad; Koziel, Violette; Pillot, Thierry; Harte, Michael K (J Alzheimers Dis, 2018)
BACKGROUND: With current treatments for Alzheimer's disease (AD) only providing temporary symptomatic benefits, disease modifying drugs are urgently required. This approach relies on improved understanding of the early pathophysiology of AD. A new hypothesis has emerged, in which early memory loss is considered a synapse failure caused by soluble amyloid-β oligomers (Aβo). These small soluble Aβo, which precede the formation of larger fibrillar assemblies, may be the main cause of early AD pathologies. OBJECTIVE: The aim of the current study was to investigate the effect of acute administration of stabilized low-n amyloid-β1-42 oligomers (Aβo1-42) on cognitive, inflammatory, synaptic, and neuronal markers in the rat. METHODS: Female and male Lister Hooded rats received acute intracerebroventricular (ICV) administration of either vehicle or 5 nmol of Aβo1-42 (10μL). Cognition was assessed in the novel object recognition (NOR) paradigm at different time points. Levels of inflammatory (IL-1β, IL-6, TNF-α), synaptic (PSD-95, SNAP-25), and neuronal (n-acetylaspartate, parvalbumin-positive cells) markers were investigated in different brain regions (prefrontal and frontal cortex, striatum, dorsal and ventral hippocampus). RESULTS: Acute ICV administration of Aβo1-42 induced robust and enduring NOR deficits. These deficits were reversed by acute administration of donepezil and rolipram but not risperidone. Postmortem analysis revealed an increase in inflammatory markers, a decrease in synaptic markers and parvalbumin containing interneurons in the frontal cortex, with no evidence of widespread neuronal loss. CONCLUSION: Taken together the results suggest that acute administration of soluble low-n Aβo may be a useful model to study the early mechanisms involved in AD and provide us with a platform for testing novel therapeutic approaches that target the early underlying synaptic pathology.

Statins and Brain Health: Alzheimer's Disease and Cerebrovascular Disease Biomarkers in Older Adults. - Ramanan, Vijay K; Przybelski, Scott A; Graff-Radford, Jonathan; Castillo, Anna M; Lowe, Val J; Mielke, Michelle M; Roberts, Rosebud O; Reid, Robert I; Knopman, David S; Jack, Clifford R; Petersen, Ronald C; Vemuri, Prashanthi (J Alzheimers Dis, 2018)
BACKGROUND: Statins have been proposed to reduce the risk of Alzheimer's disease (AD). OBJECTIVE: Assess whether long-term statin use was associated with neuroimaging biomarkers of aging and dementia. METHODS: Methods: We analyzed neuroimaging biomarkers in 1,160 individuals aged 65+ from the Mayo Clinic Study of Aging, a population-based prospective longitudinal study of cognitive aging. RESULTS: Statin-treated (5+ years of therapy) individuals had greater burden of mid-and late-life cardiovascular disease (p < 0.001) than statin-untreated (≤3 months) individuals. Lower fractional anisotropy in the genu of the corpus callosum, an early marker of cerebrovascular disease, was associated with long-term statin exposure (p < 0.035). No significant associations were identified between long-term statin exposure and cerebral amyloid or tau burden, AD pattern neurodegeneration, or white matter hyperintensity burden. CONCLUSIONS: Long-term statin therapy was not associated with differences in AD biomarkers. Individuals with long-term statin exposure had worse white matter integrity in the genu of the corpus callosum, consistent with the coexistence of higher cerebrovascular risk factor burden in this group.

Stereological Investigation of the Effects of Treadmill Running Exercise on the Hippocampal Neurons in Middle-Aged APP/PS1 Transgenic Mice. - Chao, Fenglei; Jiang, Lin; Zhang, Yi; Zhou, Chunni; Zhang, Lei; Tang, Jing; Liang, Xin; Qi, Yingqiang; Zhu, Yanqing; Ma, Jing; Tang, Yong (J Alzheimers Dis, 2018)
The risk of cognitive decline during Alzheimer's disease (AD) can be reduced if physical activity is maintained; however, the specific neural events underlying this beneficial effect are still uncertain. To quantitatively investigate the neural events underlying the effect of running exercise on middle-aged AD subjects, 12-month-old male APP/PS1 mice were randomly assigned to a control group or running group, and age-matched non-transgenic littermates were used as a wild-type group. AD running group mice were subjected to a treadmill running protocol (regular and moderate intensity) for four months. Spatial learning and memory abilities were assessed using the Morris water maze. Hippocampal amyloid plaques were observed using Thioflavin S staining and immunohistochemistry. Hippocampal volume, number of neurons, and number of newborn cells (BrdU+ cells) in the hippocampus were estimated using stereological techniques, and newborn neurons were observed using double-labelling immunofluorescence. Marked neuronal loss in both the CA1 field and dentate gyrus (DG) and deficits in both the neurogenesis and survival of new neurons in the DG of middle-aged APP/PS1 mice were observed. Running exercise could improve the spatial learning and memory abilities, reduce amyloid plaques in the hippocampi, delay neuronal loss, induce neurogenesis, and promote the survival of newborn neurons in the DG of middle-aged APP/PS1 mice. Exercise-induced protection of neurons and adult neurogenesis within the DG might be part of the important structural basis of the improved spatial learning and memory abilities observed in AD mice.

Stereological Quantification of Plaques and Tangles in Neocortex from Alzheimer's Disease Patients. - Madsen, Jes Buster; Folke, Jonas; Pakkenberg, Bente (J Alzheimers Dis, 2018)
We estimated by stereological methods the neocortical volume occupied by plaques and tangles in females dying with severe Alzheimer's disease (AD), age-matched female subjects with severe vascular dementia (VaD), and normal control brains. Stereological investigations include a uniform sampling of the tissue in the whole of neocortex and its subdivisions. Resultant volume estimates provide information about the overall burden of these two pathological changes and their volume fractions and allow for correlational studies between the pathological changes and factors such as the total neocortical neuronal cell numbers, dementia test scores, and age. We estimated the volume of plaques and tangles in the entire neocortex and frontal-, temporal-, parietal-, and occipital cortex in nine female AD brains, four female patients dying with VaD, and six neurologically normal female control brains using point-counting in uniform samples of neocortex. The volume occupied by plaques comprised approximately 1% of neocortex, while the neocortical tangles made up approximately 0.1% of neocortex of AD patients but were scarcely present in the other study groups. The individual tangle and plaque volumes did not correlate to the ultimate dementia score of the AD subjects, despite correlating with reduced neocortical volume. In neocortex of AD patients, the burden of plaques and tangles is much higher than that in patients with severe vascular dementia or normal older women but only occupy a small fraction of the neocortical volume.

Stimulation of SIRT1 Attenuates the Level of Oxidative Stress in the Brains of APP/PS1 Double Transgenic Mice and in Primary Neurons Exposed to Oligomers of the Amyloid-β Peptide. - Dong, Yang-Ting; Cao, Kun; Tan, Long-Chun; Wang, Xiao-Ling; Qi, Xiao-Lan; Xiao, Yan; Guan, Zhi-Zhong (J Alzheimers Dis, 2018)
In the study, we examined whether the silent information regulator 1 (SIRT1) can attenuate oxidative stress in the brains of mice carrying the APP/PS1 double mutation and/or in primary neonatal rat neurons exposed to oligomers of amyloid-β peptide (AβOs). Starting at 4 or 8 months of age, the transgenic mice were treated with resveratrol (RSV, a stimulator of SIRT1) or suramin (an inhibitor) (each 20 mg/kg BW/day) for two months. The primary neurons were exposed to AβOs (0.5 μM) for 48 h and thereafter RSV (20 μM) or suramin (300 mg/ml) for 24 h. Cell viability was assessed by the CCK-8 assay; SIRT1 protein and mRNA determined by western blotting and real-time PCR, respectively; senile plaques examined immunohistochemically; ROS monitored by flow cytometry; and the contents of OH-, H2O2, O2·-, and MDA, and the activities of SOD and GSH-Px measured by standard biochemical procedures. In comparison to wild-type mice or untreated primary neurons, the expression of SIRT1 was significantly lower in the brains of APP/PS1 mice or neurons exposed to AβOs. In these same systems, increased numbers of senile plaques and a high level of oxidative stress were apparent. Interestingly, these two latter changes were attenuated by treatment with RSV, but enhanced by suramin. These findings indicate that SIRT1 may be neuroprotective.

Structural Anatomical Investigation of Long-Term Memory Deficit in Behavioral Frontotemporal Dementia. - Bertoux, Maxime; Flanagan, Emma C; Hobbs, Matthew; Ruiz-Tagle, Amparo; Delgado, Carolina; Miranda, Marcelo; Ibáñez, Agustín; Slachevsky, Andrea; Hornberger, Michael (J Alzheimers Dis, 2018)
Although a growing body of work has shown that behavioral variant frontotemporal dementia (bvFTD) could present with severe amnesia in approximately half of cases, memory assessment is currently the clinical standard to distinguish bvFTD from Alzheimer's disease (AD). Thus, the concept of "relatively preserved episodic memory" in bvFTD remains the basis of its clinical distinction from AD and a criterion for bvFTD's diagnosis. This view is supported by the idea that bvFTD is not characterized by genuine amnesia and hippocampal degeneration, by contrast to AD. In this multicenter study, we aimed to investigate the neural correlates of memory performance in bvFTD as assessed by the Free and Cued Selective Reminding Test (FCSRT). Imaging explorations followed a two-step procedure, first relying on a visual rating of atrophy of 35 bvFTD and 34 AD patients' MRI, contrasted with 29 controls; and then using voxel-based morphometry (VBM) in a subset of bvFTD patients. Results showed that 43% of bvFTD patients presented with a genuine amnesia. Data-driven analysis on visual rating data showed that, in bvFTD, memory recall & storage performances were significantly predicted by atrophy in rostral prefrontal and hippocampal/perihippocampal regions, similar to mild AD. VBM results in bvFTD (pFWE<0.05) showed similar prefrontal and hippocampal regions in addition to striatal and lateral temporal involvement. Our findings showed the involvement of prefrontal as well as medial/lateral temporal atrophy in memory deficits of bvFTD patients. This contradicts the common view that only frontal deficits explain memory impairment in this disease and plead for an updated view on memory dysfunctions in bvFTD.

Structural Connectivity Alterations Along the Alzheimer's Disease Continuum: Reproducibility Across Two Independent Samples and Correlation with Cerebrospinal Fluid Amyloid-β and Tau. - Tucholka, Alan; Grau-Rivera, Oriol; Falcon, Carles; Rami, Lorena; Sánchez-Valle, Raquel; Lladó, Albert; Gispert, Juan Domingo; Molinuevo, José Luis (J Alzheimers Dis, 2018)
BACKGROUND: Gray matter changes associated with the progression of Alzheimer's disease (AD) have been thoroughly studied. However, alterations in white matter tracts have received less attention, particularly during early or preclinical stages of the disease. OBJECTIVE: To identify the structural connectivity changes across the AD continuum. METHODS: We performed probabilistic tractography in a total of 183 subjects on two independent samples that include control (n = 68) and preclinical AD individuals (n = 28), patients diagnosed with mild cognitive impairment (MCI) due to AD (n = 44), and AD patients (n = 43). We compared the connectivity between groups, and with CSF Aβ42 and tau biomarkers. RESULTS: We observed disconnections in preclinical individuals, mainly located in the temporal lobe. This pattern of disconnection spread to the parietal and frontal lobes at the MCI stage and involved almost all the brain in AD. These findings were not driven by gray matter atrophy. DISCUSSION: Using tractography, we were able to identify white matter changes between subsequent disease stages and, notably, also in preclinical AD. Therefore, this method may be useful for detecting early and specific brain structural changes during preclinical AD stage.
Keywords: Aged; Alzheimer Disease; Amyloid beta-Peptides; Atrophy; Biomarkers; Case-Control Studies; Cognitive Dysfunction; Cohort Studies; Disease Progression; Female; Gray Matter; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Neuropsychological Tests; Reproducibility of Results; Spain; tau Proteins; White Matter

A Study of a Supplement Containing Huperzine A and Curcumin in Dementia Patients and Individuals with Mild Cognitive Impairment. - Tabira, Takeshi; Kawamura, Nobutoshi (J Alzheimers Dis, 2018)
Extracts from Huperzia serrata (HS) function as a cholinesterase inhibitor and a glutamic acid receptor antagonist. We tested a supplement containing HS extracts, curcumin, and others in dementia patients and individuals with mild cognitive impairment (MCI) in an open label study. Most patients with Alzheimer's disease, dementia with Lewy bodies, and MCI individuals exhibited improvements in cognitive functions, as assessed by the Alzheimer's Disease Assessment Scale-cognitive subscale Japanese version. The scores were significantly improved at 6-12 weeks compared with baseline scores (p = 0.007) and at 22-28 weeks (p = 0.004). Thus, this supplement may be administered to dementia patients as well as MCI individuals.

A Study of Amyloid-β and Phosphotau in Plaques and Neurons in the Hippocampus of Alzheimer's Disease Patients. - Furcila, Diana; DeFelipe, Javier; Alonso-Nanclares, Lidia (J Alzheimers Dis, 2018)
The main pathological hallmarks in Alzheimer's disease (AD) are the presence of extracellular amyloid plaques, primarily consisting of amyloid-β (Aβ) peptide, and the accumulation of paired helical filaments of hyperphosphorylated tau protein (PHF-Tau) within neurons. Since CA1 is one of the most affected regions in AD, mainly at early stages, we have performed a detailed analysis of the CA1 region from 11 AD patients (demented and clinically similar; Braak stages IV-VI) to better understand the possible relationship between the presence and distribution of different neurochemical types of Aβ plaques and PHF-Tau immunoreactive  (- ir)  neurons. Hence, we have examined hippocampal sections in confocal microscopy images from double and triple-immunostained sections, to study labeled plaques and PHF-Tau-ir neurons using specific software tools. There are four main findings in the present study. First, the pyramidal layer of proximal CA1 (close to CA2) contains the smallest number of both plaques and PHF-Tau-ir neurons. Second, a large proportion of Aβ-ir plaques were also characterized by the presence of PHF-Tau-ir. Third, all plaques containing one of the two PHF-Tau isoforms also express the other isoform, that is, if a plaque contains PHFpS396, it also contains PHFAT8, and vice versa. Fourth, the coexpression study of both PHF-Tau isoforms in CA1 neurons revealed that most of the labeled neurons express only PHFpS396. Our findings further support the idea that AD is not a unique entity even within the same neuropathological stage, since the microanatomical/neurochemical changes that occur in the hippocampus greatly vary from one patient to another.

Subjective Cognitive Decline and APOE ɛ4: A Systematic Review. - Ali, Jordan I; Smart, Colette M; Gawryluk, Jodie R (J Alzheimers Dis, 2018)
Individuals with subjective cognitive decline (SCD) report self-perceived declines in cognitive function but perform within normal limits on standardized tests. However, for some, these self-perceived changes may herald eventual decline to Alzheimer's disease (AD). In light of this, the relationship between SCD and APOE ɛ4, a known genetic risk factor for AD, has garnered interest; however, no systematic review of this literature exists. The current review (n = 36 articles) examined the prevalence of APOE ɛ4 in SCD samples relative to healthy and objectively impaired samples, and summarized APOE ɛ4-related risk of conversion from SCD to AD. Univariate ANOVA indicated that APOE ɛ4 frequency was comparable between healthy control and SCD samples, yet significantly higher in objectively impaired samples (i.e., MCI, AD) relative to either of these groups. Narrative review provided mixed evidence linking coincident APOE ɛ4-positive genotype and SCD to structural neuropathology. Though there was little evidence to suggest that APOE ɛ4 predisposes individuals to developing SCD, both APOE ɛ4 and SCD were found to confer individual and multiplicative risk of conversion to objective cognitive impairment. Combined, it is likely that a relationship between APOE ɛ4, SCD, and AD exists, though its exact nature remains undetermined. A clearer understanding of these relationships is hindered by a lack of standardization in SCD classification and a dearth of longitudinal outcome research. Wide-scale adoption of genetic screening for dementia risk in persons with SCD is considered premature at this time. Ethical considerations and clinical implications of genetic testing for dementia risk are discussed.

Subjective Cognitive Decline Is Associated with Greater White Matter Hyperintensity Volume. - van Rooden, Sanneke; van den Berg-Huysmans, Annette A; Croll, Pauline H; Labadie, Gerda; Hayes, Jessica M; Viviano, Raymond; van der Grond, Jeroen; Rombouts, Serge A R B; Damoiseaux, Jessica S (J Alzheimers Dis, 2018)
BACKGROUND: Research in older adults with subjective cognitive decline (SCD) has mainly focused on Alzheimer's disease (AD)-related MRI markers, such as hippocampal volume. However, small vessel disease (SVD) is currently established as serious comorbidity in dementia and its preliminary stages. It is therefore important to examine SVD markers in addition to AD markers in older adults presenting with SCD. OBJECTIVE: The aim of our study was to elucidate the role of SVD markers in late middle-aged to older adults with and without SCD in addition to the commonly found role of AD markers (hippocampal volume). METHODS: 67 healthy late middle-aged to older adults participated in this study (mean age 68 years); 25 participants with SCD and 42 participants without SCD. We evaluated quantitative as well as qualitative AD markers (i.e., hippocampal volume and medial temporal lobe atrophy (MTA) scale) and SVD markers (i.e., white matter hyperintensities (WMH) volume, Fazekas scale, microbleeds, and lacunar infarcts), and neuropsychological function and amount of memory complaints. RESULTS: We found a significant effect of SCD on hippocampal atrophy, as assessed using the MTA scale, but not on hippocampal volume. In addition, we found a significant effect of SCD, and amount of memory complaints, on WMH volume and Fazekas score, suggesting larger WMH volumes in participants with SCD. CONCLUSION: SVD MRI markers are related to amount of memory complaints, in addition to the commonly observed AD MRI markers, as demonstrated by the greater WMHs in healthy late middle-aged to older adults with SCD.

Subjective Cognitive Decline, Objective Cognition, and Depression in Older Hispanics Screened for Memory Impairment. - Zlatar, Zvinka Z; Muniz, Martha C; Espinoza, Sarah G; Gratianne, Roberto; Gollan, Tamar H; Galasko, Douglas; Salmon, David P (J Alzheimers Dis, 2018)
Subjective cognitive decline (SCD) is common in older adults and may be an early marker of future cognitive decline. Research suggest that SCD is more closely related to concurrent symptoms of depression than to objective cognitive performance in non-Hispanic Whites, but it is unknown whether the associations of SCD, cognition, and depression manifest differently in Hispanic older adults. We examined if SCD is associated with objective cognitive performance or with depression symptoms in 145 Hispanic individuals ages 60 or older referred by community health clinics for screening of cognitive complaints. All participants lived near the U.S.-Mexico border, spoke Spanish only, or were Spanish-English bilingual. Memory-only and global cognitive composites were created from scores on Spanish versions of several neuropsychological tests. The Geriatric Depression Scale (GDS) and a five-item SCD questionnaire developed by our group were also completed. Multiple regression analyses showed no significant associations between SCD and memory or global cognitive composite scores after adjusting for age, sex, education, and GDS score. In contrast, there was a significant association between GDS and SCD after adjusting for age, sex, education, global and memory composite scores. Findings suggest that SCD does not accurately reflect current cognitive status in older Hispanics who present to their primary care physician with cognitive complaints. Clinicians should interpret SCD in this population within the context of information about symptoms of depression. Longitudinal research is needed in older Hispanics to better characterize SCD in this population and to determine if it can predict future cognitive decline.

Subjective Cognitive Decline Prediction of Mortality: Results from the Einstein Aging Study. - Katz, Mindy J; Wang, Cuiling; Derby, Carol A; Lipton, Richard B; Zimmerman, Molly E; Sliwinski, Martin J; Rabin, Laura A (J Alzheimers Dis, 2018)
BACKGROUND: The relation of pre-dementia stages to mortality has not been fully explored. Previous work examining subjective cognitive decline (SCD) and mortality is limited and mixed regarding methods used and consistency of findings. OBJECTIVE: To examine SCD and mortality in a longitudinal, community-based cohort, using item response theory (IRT) methodology to form a composite SCD measure. Also, to assess whether this relationship was independent of clinical cognitive status. METHODS: The Einstein Aging Study is a diverse longitudinal cohort of adults aged ≥70. SCD items were extracted from baseline CERAD questionnaires and a composite score was formed using IRT methodology. A total of 1,741 participants with complete data were clinically diagnosed as cognitively normal, or as having amnestic mild cognitive impairment (aMCI), nonamnestic mild cognitive impairment (naMCI), or dementia. 645 deaths occurred over a period of 8,912 person-years of follow-up. Cox proportional hazard models predicted time to death adjusting for covariates. RESULTS: A one standard deviation unit increase in level of SCD was associated with >20% higher risk of mortality. However, when models were adjusted for clinical cognitive status, the association was no longer significant. Both dementia and aMCI predicted mortality. Furthermore, when analyses focused only on those without cognitive impairment, SCD level did not predict mortality. CONCLUSIONS: The association of SCD with mortality may be due to the association of SCD with clinical cognitive status. Thus, SCD may be used as a community-based screen to initially identify those with cognitive impairment who may be at greatest risk for death.

Subjective Sleep Quality is not Associated with Incident Dementia: The Rotterdam Study. - Lysen, Thom S; Wolters, Frank J; Luik, Annemarie I; Ikram, M Kamran; Tiemeier, Henning; Ikram, M Arfan (J Alzheimers Dis, 2018)
BACKGROUND: Poor sleep is related to higher dementia risk, but this association is more equivocal for subjective sleep quality specifically. This study investigates the link between subjective sleep quality and dementia risk in the general population. OBJECTIVE: To study the role of subjective sleep quality in the risk of dementia in the general population. METHODS: In the prospective population-based Rotterdam Study, 4,835 persons (mean age 72 years, 58% women) underwent a home interview (2002- 2006) that included the validated Pittsburgh Sleep Quality Index (PSQI) to assess sleep quality. Participants were followed until 2015 for incident dementia, through in-person screening and continuous monitoring of medical records. We used Cox regression models to associate sleep quality with dementia risk, adjusting for age, sex, education, smoking, employment, coffee consumption, alcohol consumption, activities of daily living, cardiovascular risk factors, anxiety, depressive symptoms, cognition, and snoring. RESULTS: During 41,385 person-years (8.5 years mean), 420 participants developed dementia, of whom 320 Alzheimer's disease (AD). Poorer subjective sleep quality was not associated with the risk of all-cause dementia (hazard ratio [HR] per SD increase in PSQI score: 0.91, 95% CI 0.82- 1.02) or AD (HR 0.92, 95% CI 0.81- 1.05). Similarly, individual components of the PSQI were also not associated with dementia. Several sensitivity analyses, i.e., excluding last years of the follow-up time duration or restricting to those with best MMSE scores at baseline, did not reveal subgroups with increased risks. CONCLUSION: In this study, we found no association of poor subjective sleep quality with higher risk of dementia.

Subtle Cognitive Impairment and Alzheimer's Disease-Type Pathological Changes in Cerebrospinal Fluid are Common Among Neurologically Healthy Subjects. - Haapalinna, Fanni; Kokki, Merja; Jääskeläinen, Olli; Hallikainen, Merja; Helisalmi, Seppo; Koivisto, Anne; Kokki, Hannu; Paajanen, Teemu; Penttinen, Janne; Pikkarainen, Maria; Rautiainen, Minna; Soininen, Hilkka; et al. (J Alzheimers Dis, 2018)
BACKGROUND: The neuropathology of Alzheimer's disease (AD) has previously been shown to be rather common among the elderly. OBJECTIVE: The aim of this study was to inspect the associations between cerebrospinal fluid (CSF) AD biomarker concentrations, age, the APOEɛ4 allele, cardiovascular diseases, diabetes, and cognitive performance in a cohort of a neurologically healthy population. METHODS: This study included 93 subjects (42 men, mean age 67 years) without previous neurological symptoms or subjective cognitive complaints. Their cognition was assessed, and CSF biomarkers and APOEɛ4 status were analyzed. RESULTS: Of the studied subjects, 8.6% (n = 8) had a pathological CSF AD biomarker profile. An increase in age correlated positively with CSF tau pathology and negatively with global cognitive performance. CONCLUSION: AD-type pathological changes in CSF and subtle cognitive impairment are common within a population with no previous memory complaints. Age was the main risk factor for the changes.

Subtypes Based on Neuropsychological Performance Predict Incident Dementia: Findings from the Rush Memory and Aging Project. - Zammit, Andrea R; Muniz-Terrera, Graciela; Katz, Mindy J; Hall, Charles B; Ezzati, Ali; Bennett, David A; Lipton, Richard B (J Alzheimers Dis, 2018)
BACKGROUND: In a previous report, we used latent class analysis (LCA) to identify natural subgroups of older adults in the Einstein Aging Study (EAS) based on neuropsychological performance. These subgroups differed in demographics, genetic profile, and prognosis. Herein, we assess the generalizability of these findings to an independent sample, the Rush Memory and Aging Project (MAP), which used an overlapping, but distinct neuropsychological battery. OBJECTIVE: Our aim was to identify the association of natural subgroups based on neuropsychological performance in the MAP cohort with incident dementia and compare them with the associations identified in the EAS. METHODS: MAP is a community-dwelling cohort of older adults living in the northeastern Illinois, Chicago. Latent class models were applied to baseline scores of 10 neuropsychological measures across 1,662 dementia-free MAP participants. Results were compared to prior findings from the EAS. RESULTS: LCA resulted in a 5-class model: Mixed-Domain Impairment (n = 71, 4.3%), Memory-specific-Impairment (n = 274, 16.5%), Average (n = 767, 46.1%), Frontal Impairment (n = 222, 13.4%), and a class of Superior Cognition (n = 328, 19.7%). Similar to the EAS, the Mixed-Domain Impairment, the Memory-Specific Impairment, and the Frontal Impairment classes had higher risk of incident Alzheimer's disease when compared to the Average class. By contrast, the Superior Cognition had a lower risk of Alzheimer's disease when compared to the Average class. CONCLUSIONS: Natural cognitive subgroups in MAP are similar to those identified in EAS. These similarities, despite study differences in geography, sampling strategy, and cognitive tests, suggest that LCA is capable of identifying classes that are not limited to a single sample or a set of cognitive tests.

Sulforaphane Inhibits the Generation of Amyloid-β Oligomer and Promotes Spatial Learning and Memory in Alzheimer's Disease (PS1V97L) Transgenic Mice. - Hou, Ting-Ting; Yang, He-Yun; Wang, Wei; Wu, Qiao-Qi; Tian, Yuan-Ruhua; Jia, Jian-Ping (J Alzheimers Dis, 2018)
Abnormal amyloid-β (Aβ) aggregates are a striking feature of Alzheimer's disease (AD), and Aβ oligomers have been proven to be crucial in the pathology of AD. Any intervention targeting the generation or aggregation of Aβ can be expected to be useful in AD treatment. Oxidative stress and inflammation are common pathological changes in AD that are involved in the generation and aggregation of Aβ. In the present study, 6-month-old PS1V97L transgenic (Tg) mice were treated with sulforaphane, an antioxidant, for 4 months, and this treatment significantly inhibited the generation and aggregation of Aβ. Sulforaphane also alleviated several downstream pathological changes that including tau hyperphosphorylation, oxidative stress, and neuroinflammation. Most importantly, the cognition of the sulforaphane-treated PS1V97L Tg mice remained normal compared to that of wild-type mice at 10 months of age, when dementia typically emerges in PS1V97L Tg mice. Pretreating cultured cortical neurons with sulforaphane also protected against neuronal injury caused by Aβ oligomers in vitro. These findings suggest that sulforaphane may be a potential compound that can inhibit Aβ oligomer production in AD.

Supplemental Retinal Carotenoids Enhance Memory in Healthy Individuals with Low Levels of Macular Pigment in A Randomized, Double-Blind, Placebo-Controlled Clinical Trial. - Power, Rebecca; Coen, Robert F; Beatty, Stephen; Mulcahy, Riona; Moran, Rachel; Stack, Jim; Howard, Alan N; Nolan, John M (J Alzheimers Dis, 2018)
BACKGROUND: There is a biologically plausible rationale whereby the dietary carotenoids lutein (L), zeaxanthin (Z), and meso-zeaxanthin (MZ), which are collectively referred to as macular pigment (MP) in the central retina (macula), support the maintenance of cognition via their antioxidant and anti-inflammatory properties. OBJECTIVE: To investigate the impact of supplemental L, Z, and MZ on memory, executive function, and verbal fluency among healthy individuals with low MP levels. METHODS: In this double-blind, placebo-controlled, randomized clinical trial, subjects (n = 91; mean±SD age = 45.42±12.40; % male = 51.6) consumed a daily formulation of 10 mg L, 10 mg MZ, and 2 mg Z (n = 45) or placebo (n = 46) for 12 months. Cognitive domains assessed included verbal and visual learning, immediate and delayed memory, executive function, and verbal fluency. MP and serum carotenoid concentrations of L, Z, and MZ were also measured. RESULTS: Following 12-month supplementation, individuals in the active group exhibited statistically significant improvements in memory when compared to the placebo group (paired associated learning [PAL] memory score [rANOVA, p = 0.009]; PAL errors [rANOVA, p = 0.017]). Furthermore, the observed reduction in the number of errors made in the PAL task among those in the intervention group was positively and significantly related to observed increases in MP volume (p = 0.005) and observed increases in serum concentrations of L (p = 0.009). CONCLUSION: This randomized, double-blind, placebo-controlled clinical trial demonstrates a memory-enhancing effect of daily supplementation with L, Z, and MZ in healthy subjects with low MP at baseline. The implications of these findings for intellectual performance throughout life, and for risk of cognitive decline in later life, warrant further study.
Keywords: Adult; Cognition; Dietary Supplements; Double-Blind Method; Executive Function; Female; Healthy Volunteers; Humans; Lutein; Macular Pigment; Male; Memory, Episodic; Middle Aged; Retina; Vision Tests; Zeaxanthins

A Survey of Patient and Partner Outcome and Treatment Preferences in Mild Cognitive Impairment. - Smith, Glenn E; Chandler, Melanie; Fields, Julie A; Aakre, Jeremiah; Locke, Dona E C (J Alzheimers Dis, 2018)
BACKGROUND: The patient-centered movement in health care is increasing efforts to design studies and interventions that address the outcomes that matter most to patients and their families. Research has not adequately addressed Alzheimer's disease patient and caregiver preferences. OBJECTIVE: To survey the outcome and treatment preferences of patients and caregivers who had completed a multicomponent behavioral intervention for mild cognitive impairment (MCI). METHODS: Extending prior work, we conducted an online survey regarding outcome and intervention preferences. Participants were patients with MCI and partners who completed the HABIT Healthy Action to Benefit Independence & Thinking ® program. RESULTS: Both patient and partner respondents ranked patient quality of life as the highest priority, followed by patient self-efficacy, functional status, patient mood, and patient memory performance. Distressing behaviors and caregiver outcomes (burden, mood, and self-efficacy) had low rankings. Regarding the importance of HABIT ® program components, memory compensation training was ranked highest and wellness education lowest by all groups. CONCLUSION: Additional research should compare patient preference for patient reported outcomes, traditional neuropsychological and clinician outcomes, and modern biomarker outcomes.

Sweet Mitochondria: A Shortcut to Alzheimer's Disease. - Moreira, Paula I (J Alzheimers Dis, 2018)
A growing body of evidence supports a clear association between Alzheimer's disease and diabetes and several mechanistic links have been revealed. This paper is mainly devoted to the discussion of the role of diabetes-associated mitochondrial defects in the pathogenesis of Alzheimer's disease. The research experience and views of the author on this subject will be highlighted.

Synergistic Protective Effects of Mitochondrial Division Inhibitor 1 and Mitochondria-Targeted Small Peptide SS31 in Alzheimer's Disease. - Reddy, P Hemachandra; Manczak, Maria; Yin, XiangLing; Reddy, Arubala P (J Alzheimers Dis, 2018)
The purpose of our study was to determine the synergistic protective effects of mitochondria-targeted antioxidant SS31 and mitochondria division inhibitor 1 (Mdivi1) in Alzheimer's disease (AD). Using biochemical methods, we assessed mitochondrial function by measuring the levels of hydrogen peroxide, lipid peroxidation, cytochrome c oxidase activity, mitochondrial ATP, and GTPase Drp1 enzymatic activity in mutant AβPP cells. Using biochemical methods, we also measured cell survival and apoptotic cell death. Amyloid-β (Aβ) levels were measured using sandwich ELISA, and using real-time quantitative RT-PCR, we assessed mtDNA (mtDNA) copy number in relation to nuclear DNA (nDNA) in all groups of cells. We found significantly reduced levels of Aβ40 and Aβ42 in mutant AβPP cells treated with SS31, Mdivi1, and SS31+Mdivi1, and the reduction of Aβ42 levels were much higher in SS31+Mdivi1 treated cells than individual treatments of SS31 and Mdivi1. The levels of mtDNA copy number and cell survival were significantly increased in SS31, Mdivi1, and SS31+Mdivi1 treated mutant AβPP cells; however, the increased levels of mtDNA copy number and cell survival were much higher in SS31+Mdivi1 treated cells than individual treatments of SS31 and Mdivi1. Mitochondrial dysfunction is significantly reduced in SS31, Mdivi1, and SS31+Mdivi1 treated mutant AβPP cells; however, the reduction is much higher in cells treated with both SS31+Mdvi1. Similarly, GTPase Drp1 activity is reduced in all treatments, but reduced much higher in SS31+Mdivi1 treated cells. These observations strongly suggest that combined treatment of SS31+Mdivi1 is effective than individual treatments of SS31 and Mdivi1. Therefore, we propose that combined treatment of SS31+Mdivi1 is a better therapeutic strategy for AD. Ours is the first study to investigate combined treatment of mitochondria-targeted antioxidant SS31 and mitochondrial division inhibitor 1 in AD neurons.

Synthetic Fragment of Receptor for Advanced Glycation End Products Prevents Memory Loss and Protects Brain Neurons in Olfactory Bulbectomized Mice. - Volpina, Olga M; Samokhin, Alexandr N; Koroev, Dmitriy O; Nesterova, Inna V; Volkova, Tatyana D; Medvinskaya, Natalia I; Nekrasov, Pavel V; Tatarnikova, Olga G; Kamynina, Anna V; Balasanyants, Samson M; Voronina, Tamara A; Kulikov, Alexey M; et al. (J Alzheimers Dis, 2018)
Activation of receptor for advanced glycation end products (RAGE) plays an essential role in the development of Alzheimer's disease (AD). It is known that the soluble isoform of the receptor binds to ligands and prevents negative effects of the receptor activation. We proposed that peptide fragments from RAGE prevent negative effects of the receptor activation during AD neurodegeneration. We have synthesized peptide fragments from surface-exposed regions of RAGE. Peptides were intranasally administrated into olfactory bulbectomized (OBX) mice, which developed some characteristics similar to AD neurodegeneration. We have found that only insertion of fragment (60-76) prevents the memory of OBX mice. Immunization of OBX mice with peptides showed that again only (60-76) peptide protected the memory of animals. Both intranasal insertion and immunization decreased the amyloid-β (Aβ) level in the brain. Activity of shortened fragments of (60-76) peptide was tested and showed only the (60-70) peptide is responsible for manifestation of activity. Intranasal administration of (60-76) peptide shows most protective effect on morpho-functional characteristics of neurons in the cortex and hippocampal areas. Using Flu-(60-76) peptide, we revealed its penetration in the brain of OBX mice as well as colocalization of Flu-labeled peptide with Aβ in the brain regions in transgenic mice. Flu-(60-76) peptide complex with trimer of Aβ was detected by SDS-PAGE. These data indicate that Aβ can be one of the molecular target of (60-70) peptide. These findings provide a new peptide molecule for design of anti-AD drug and for investigation of RAGE activation ways in progression of AD neurodegeneration.
Keywords: Administration, Intranasal; Animals; Behavior, Animal; Brain; Disease Models, Animal; Male; Maze Learning; Memory Disorders; Mice; Mice, Transgenic; Neurons; Olfactory Bulb; Peptide Fragments; Receptor for Advanced Glycation End Products

A Systematic Review and Aggregated Analysis on the Impact of Amyloid PET Brain Imaging on the Diagnosis, Diagnostic Confidence, and Management of Patients being Evaluated for Alzheimer's Disease. - Fantoni, Enrico R; Chalkidou, Anastasia; O' Brien, John T; Farrar, Gill; Hammers, Alexander (J Alzheimers Dis, 2018)
BACKGROUND: Amyloid PET (aPET) imaging could improve patient outcomes in clinical practice, but the extent of impact needs quantification. OBJECTIVE: To provide an aggregated quantitative analysis of the value added by aPET in cognitively impaired subjects. METHODS: Systematic literature searches were performed in Embase and Medline until January 2017. 1,531 cases over 12 studies were included (1,142 cases over seven studies in the primary analysis where aPET was the key biomarker; the remaining cases included as defined groups in the secondary analysis). Data was abstracted by consensus among two observers and assessed for bias. Clinical utility was measured by diagnostic change, diagnostic confidence, and patient management before and after aPET. Three groups were further analyzed: control patients for whom feedback of aPET scan results was delayed; aPET Appropriate Use Criteria (AUC+) cases; and patients undergoing additional FDG/CSF testing. RESULTS: For 1,142 cases with only aPET, 31.3% of diagnoses were revised, whereas 3.2% of diagnoses changed in the delayed aPET control group (p < 0.0001). Increased diagnostic confidence following aPET was found for 62.1% of 870 patients. Management changes with aPET were found in 72.2% of 740 cases and in 55.5% of 299 cases in the control group (p < 0.0001). The diagnostic value of aPET in AUC+ patients or when FDG/CSF were additionally available did not substantially differ from the value of aPET alone in the wider population. CONCLUSIONS: Amyloid PET contributed to diagnostic revision in almost a third of cases and demonstrated value in increasing diagnostic confidence and refining management plans.

A Systematic Review and Meta-Analysis on the Prevalence of Dementia in Europe: Estimates from the Highest-Quality Studies Adopting the DSM IV Diagnostic Criteria. - Bacigalupo, Ilaria; Mayer, Flavia; Lacorte, Eleonora; Di Pucchio, Alessandra; Marzolini, Fabrizio; Canevelli, Marco; Di Fiandra, Teresa; Vanacore, Nicola (J Alzheimers Dis, 2018)
BACKGROUND: Dementia, including Alzheimer's disease (AD), is one of the most burdensome medical conditions. Usually, the reviews that aim at calculating the prevalence of dementia include estimates from studies without assessing their methodological quality. Alzheimer's Disease International (ADI) proposed a score to assess the methodological quality of population-based studies aimed at estimating the prevalence of dementia. During the last three years, the European Commission has funded three projects (Eurodem, EuroCoDe, and ALCOVE) in order to estimate the prevalence of dementia in Europe. OBJECTIVE: The aim of this study was to perform a systematic review and meta-analysis of data on the prevalence of dementia in Europe derived from studies that included only subjects with a diagnosis of dementia according to the DSM IV criteria, and that had a high quality score according to ADI criteria. METHODS: We considered the studies selected by the two projects EuroCoDe (1993-2007) and Alcove (2008-2011), and we performed a new bibliographic search. For the systematic review, we only selected the subset of articles that included subjects with a diagnosis of dementia according to the DSM IV criteria. The studies were qualitatively assessed using the ADI tool. RESULTS: The meta-analysis considered 9 studies that were carried out in Europe between 1993 and 2018 including a total of 18,263 participants, of which 2,137 were diagnosed with dementia. The prevalence rate standardized for age and sex resulted 7.1%. DISCUSSION: This is the first systematic review on the prevalence of dementia in Europe considering only high-quality studies adopting the same diagnostic criteria (i.e., DSM IV).

Targeted Assessment of Enlargement of the Perivascular Space in Alzheimer's Disease and Vascular Dementia Subtypes Implicates Astroglial Involvement Specific to Alzheimer's Disease. - Boespflug, Erin L; Simon, Matthew J; Leonard, Emmalyn; Grafe, Marjorie; Woltjer, Randall; Silbert, Lisa C; Kaye, Jeffrey A; Iliff, Jeffrey J (J Alzheimers Dis, 2018)
Waste clearance from the brain parenchyma occurs along perivascular pathways. Enlargement of the perivascular space (ePVS) is associated with pathologic features of Alzheimer's disease (AD), although the mechanisms and implications of this dilation are unclear. Fluid exchange along the cerebral vasculature is dependent on the perivascular astrocytic water channel aquaporin-4 (AQP4) and loss of perivascular AQP4 localization is found in AD. We directly measured ePVS in postmortem samples of pathologically characterized tissue from participants who were cognitively intact or had AD or mixed dementia (vascular lesions with AD). We found that both AD and mixed dementia groups had significantly increased ePVS compared to cognitively intact subjects. In addition, we found increased global AQP4 expression of the AD group over both control and mixed dementia groups and a qualitative reduction in perivascular localization of AQP4 in the AD group. Among these cases, increasing ePVS burden was associated with the presence of tau and amyloid-β pathology. These findings are consistent with the existing evidence of ePVS in AD and provide novel information regarding differences in AD and vascular dementia and the potential role of astroglial pathology in ePVS.

Targeting Alzheimer's Disease at the Right Time and the Right Place: Validation of a Personalized Approach to Diagnosis and Treatment. - Gauthier, Serge; Ng, Kok Pin; Pascoal, Tharick A; Zhang, Hua; Rosa-Neto, Pedro (J Alzheimers Dis, 2018)
Cautious optimism is appropriate for a near future (five years) time frame for a number of drugs acting on the different pathophysiological components of Alzheimer's disease (amyloid deposition, tau hyperphosphorylation, neuroinflammation, vascular changes, to name the most important known so far). Since the relative weight of these components will be different between individuals and will even change over time for each individual, a 'one drug fit for all' approach is no longer defensible. Precision medicine using biomarkers in the diagnosis and treatment of Alzheimer's disease is the new strategy.

Targeting Insulin for Alzheimer's Disease: Mechanisms, Status and Potential Directions. - Lee, Jung Hyun; Jahrling, Jordan B; Denner, Larry; Dineley, Kelly T (J Alzheimers Dis, 2018)
Insulin resistance can occur when the body is unable to respond to insulin even in excess. In the brain, insulin manages glucose metabolism in regions such as the hippocampus and plays a key role in directly regulating ERK, a kinase required for the type of memory compromised in early Alzheimer's disease (AD). Human imaging studies show that brain glucose utilization declines with age and is notably impaired in subjects with early AD. Likewise, animal models of AD or insulin resistance, or both, demonstrate that dysfunctional insulin signaling and insulin resistance in the brain have reciprocity with neuroinflammation and aberrant accumulation of amyloid-β (Aβ), pathological hallmarks in AD. As such, the association between brain insulin activity and AD has led to clinical trials testing the efficacy of insulin and insulin-sensitizing drugs to intervene in AD. Based on recent inquiries to ClinicalTrials.gov, we evaluated thirty-three clinical studies related to AD and insulin. The search filtered for interventional clinical trials to test FDA-approved drugs or substances that impinge upon the insulin signaling pathway. Insulin, metformin, and thiazolidinediones were the three main interventions assessed. Overall, these strategies are expected to negate the effects of brain insulin resistance by targeting insulin signaling pathways involved in neuroinflammation, metabolic homeostasis, synaptic functional and structural integrity. The goal of this review is to provide an update on insulin and ERK signaling in relation to memory, its decline in early AD, and provide an overview of clinical trials related to insulin for early AD intervention.

Tau and Amyloid Positron Emission Tomography Imaging Predict Driving Performance Among Older Adults with and without Preclinical Alzheimer's Disease. - Roe, Catherine M; Babulal, Ganesh M; Mishra, Shruti; Gordon, Brian A; Stout, Sarah H; Ott, Brian R; Carr, David B; Ances, Beau M; Morris, John C; Benzinger, Tammie L S (J Alzheimers Dis, 2018)
Abnormal levels of Alzheimer's disease (AD) biomarkers, measured by positron emission tomography imaging using amyloid-based radiotracers and cerebrospinal fluid, are associated with impaired driving performance in older adults. We examined whether preclinical AD staging, defined using amyloid imaging and tau imaging using the radiotracer T807 (AKA flortaucipir or AV-1451), was associated with receiving a marginal/fail rating on a standardized road test (n = 42). Participants at Stage 2 (positive amyloid and tau scans) of preclinical AD were more likely to receive a marginal/fail rating compared to participants at Stage 0 or 1. Stage 2 preclinical AD may manifest in worse driving performance.
Keywords: Aged; Aged, 80 and over; Alzheimer Disease; Amyloid; Automobile Driving; Biomarkers; Carbolines; Female; Humans; Logistic Models; Male; Neuroimaging; Positron-Emission Tomography; tau Proteins

Tau Conformation as a Target for Disease-Modifying Therapy: The Role of Truncation. - Novak, Petr; Cehlar, Ondrej; Skrabana, Rostislav; Novak, Michal (J Alzheimers Dis, 2018)
Tau protein plays a major role in the pathogenesis of Alzheimer's disease. Despite many decades of intensive research, the cause of the conformational switch that leads to the remodeling of the highly flexible conformational ensemble of intrinsically disordered protein tau into insoluble filaments is still elusive. We show here that truncation of tau may play a causative role in this conformational change, as evidenced by results obtained from in vitro experiments and from transgenic animal models. This conformational change is a common denominator of pathological tau protein assemblies, and a salient drug target. The long-running research of truncated tau has led to the generation of the first active tau vaccine that has entered clinical trials.

Tau Immunotherapies for Alzheimer's Disease and Related Tauopathies: Progress and Potential Pitfalls. - Sigurdsson, Einar M (J Alzheimers Dis, 2018)
Tau immunotherapies have now advanced from proof-of-concept studies to Phase II clinical trials. This review briefly outlines developments in the field and discusses how these therapies may work, which involves multiple variables that are connected in complex ways. These various factors are likely to define therapeutic success in humans and have not been thoroughly investigated, at least based on published reports.

Tau Protein Dysfunction after Brain Ischemia. - Pluta, Ryszard; Ułamek-Kozioł, Marzena; Januszewski, Sławomir; Czuczwar, Stanisław J (J Alzheimers Dis, 2018)
Brain ischemia comprises blood-brain barrier, glial, and neuronal cells. The blood-brain barrier controls permeability of different substances and the composition of the neuronal cells 'milieu', which is required for their physiological functioning. Recent evidence indicates that brain ischemia itself and ischemic blood-brain barrier dysfunction is associated with the accumulation of neurotoxic molecules within brain tissue, e.g., different parts of amyloid-β protein precursor and changed pathologically tau protein. All these changes due to ischemia can initiate and progress neurodegeneration of the Alzheimer's disease-type. This review presents brain ischemia and ischemic blood-brain barrier as a trigger for tau protein alterations. Thus, we hypothesize that the changes in pattern of phosphorylation of tau protein are critical to microtubule function especially in neurons, and contribute to the neurodegeneration following brain ischemia-reperfusion episodes with Alzheimer's disease phenotype.

Tau Proteolysis in the Pathogenesis of Tauopathies: Neurotoxic Fragments and Novel Biomarkers. - Quinn, James P; Corbett, Nicola J; Kellett, Katherine A B; Hooper, Nigel M (J Alzheimers Dis, 2018)
With predictions showing that 131.5 million people worldwide will be living with dementia by 2050, an understanding of the molecular mechanisms underpinning disease is crucial in the hunt for novel therapeutics and for biomarkers to detect disease early and/or monitor disease progression. The metabolism of the microtubule-associated protein tau is altered in different dementias, the so-called tauopathies. Tau detaches from microtubules, aggregates into oligomers and neurofibrillary tangles, which can be secreted from neurons, and spreads through the brain during disease progression. Post-translational modifications exacerbate the production of both oligomeric and soluble forms of tau, with proteolysis by a range of different proteases being a crucial driver. However, the impact of tau proteolysis on disease progression has been overlooked until recently. Studies have highlighted that proteolytic fragments of tau can drive neurodegeneration in a fragment-dependent manner as a result of aggregation and/or transcellular propagation. Proteolytic fragments of tau have been found in the cerebrospinal fluid and plasma of patients with different tauopathies, providing an opportunity to develop these fragments as novel disease progression biomarkers. A range of therapeutic strategies have been proposed to halt the toxicity associated with proteolysis, including reducing protease expression and/or activity, selectively inhibiting protease-substrate interactions, and blocking the action of the resulting fragments. This review highlights the importance of tau proteolysis in the pathogenesis of tauopathies, identifies putative sites during tau fragment-mediated neurodegeneration that could be targeted therapeutically, and discusses the potential use of proteolytic fragments of tau as biomarkers for different tauopathies.

Tauopathies: Mechanisms and Therapeutic Strategies. - Tan, Chen-Chen; Zhang, Xiao-Yan; Tan, Lan; Yu, Jin-Tai (J Alzheimers Dis, 2018)
Tauopathies are morphologically, biochemically, and clinically heterogeneous neurodegenerative diseases defined by the accumulation of abnormal tau proteins in the brain. There is no effective method to prevent and reverse the tauopathies, but this gloomy picture has been changed by recent research advances. Evidences from genetic studies, experimental animal models, and molecular and cell biology have shed light on the main mechanisms of the diseases. The development of radiology and biochemistry, especially the development of PET imaging, will provide important biomarkers for the clinical diagnosis and treatment. Given the central role of tau in tauopathies, many treatments have constantly emerged, including targeting phosphorylation, targeting aggregation, increasing microtubule stabilization, tau immunization, clearance of tau, anti-inflammatory treatment, and other therapeutics. There is still a long way to go before we obtain drug therapy targeted at multifactor mechanisms.
Keywords: Animals; Biomarkers; Brain; Disease Models, Animal; Humans; Neuroimaging; Phosphorylation; Positron-Emission Tomography; tau Proteins; Tauopathies

TDP-43 and Alzheimer's Disease Pathologic Subtype in Non-Amnestic Alzheimer's Disease Dementia. - Sahoo, Aradhana; Bejanin, Alexandre; Murray, Melissa E; Tosakulwong, Nirubol; Weigand, Stephen D; Serie, Amanda M; Senjem, Matthew L; Machulda, Mary M; Parisi, Joseph E; Boeve, Bradley F; Knopman, David S; Petersen, Ronald C; et al. (J Alzheimers Dis, 2018)
BACKGROUND: TDP-43 has been shown to be strongly associated with memory loss, smaller hippocampal volumes, and faster rates of hippocampal atrophy in Alzheimer's disease (AD) patients with an amnestic presentation. Whether TDP-43 has any clinical or anatomical associations in AD patients with non-amnestic phenotype is unknown. OBJECTIVE: To determine whether TDP-43 plays a significant role in the clinic-anatomic features of non-amnestic AD. METHODS: All cases with pathologically confirmed intermediate-high probability AD from 1996-2012 were identified and retrospectively sub-classified into amnestic versus non-amnestic dementia at the time of presentation. Neurofibrillary tangle counts were performed in those with a non-amnestic presentation using thioflavin-S microscopy in the hippocampus and three neocortical regions, and all cases were subtyped into hippocampal-sparing, limbic-predominant, and typical AD pathology. TDP-43 immunoreactivity was used to assess for the presence of TDP-43. Statistical analyses helped determine whether pathologic subtype or TDP-43 was more strongly associated with clinico-imaging features. RESULTS: Out of 172 pathologically confirmed AD cases, 36 (19%) were classified as non-amnestic. Twenty-five of these 36 (69%) had typical pathology, 0 limbic-predominant pathology, and 11 (31%) hippocampal-sparing pathology. Eleven (44%) of the 25 cases with typical pathology were TDP-43+. Of the 11 cases with hippocampal-sparing pathology, 4 (36%) were TDP-43+. There were no differences in demographic, clinical, or neuroimaging features in those with TDP-43 versus those without except for older age at onset (p = 0.02) and age at death (p = 0.02) in those with TDP-43. AD pathological subtype accounted for slightly more of the variances in the neocortex than TDP-43. CONCLUSION: In non-amnestic AD, we find little evidence that clinical or anatomical features of the disease are related to TDP-43.

TDP-43 Neuropathologic Associations in the Nun Study and the Honolulu-Asia Aging Study. - Flanagan, Margaret E; Cholerton, Brenna; Latimer, Caitlin S; Hemmy, Laura S; Edland, Steven D; Montine, Kathleen S; White, Lon R; Montine, Thomas J (J Alzheimers Dis, 2018)
Transactive response binding protein-43 (TDP-43) cytoplasmic neuronal and glial aggregates (pathologic TDP-43) have been described in multiple brain diseases. We describe the associations between neuropathologically confirmed TDP-43 and cognition in two population-based cohorts: the Nun Study (NS) and the Honolulu-Asia Aging Study (HAAS). In the HAAS, there was a significant association between hippocampal sclerosis (HS) and TDP-43 (OR = 11.04, p < 0.0001, 95% CI 3.57-34.13). In the NS, there were significant associations between TDP-43 and HS (OR = 16.44, p > 0.001 95%, CI 7.10-38.00) and Alzheimer's disease (AD) severity (OR = 1.74, p = 0.009, 95% CI 1.15-2.64). When cognitive scores were added to the model, HS remained significant but the other variables were not. When HS was removed from the model, the overall model remained significant and the associations between cognitive performance and TDP-43 (OR = 2.11, p = 0.022, 95% CI 1.11-4.02) were significant. In the NS, there was a significant association between cognitive performance and TDP-43 (OR 1.94 p = 0.005, 95% CI 1.22-3.09) (HS remained significant, but AD did not). When HS was removed from the model, only CERAD was significant (OR = 2.43 p < 0.001, 95% CI 1.58-3.74). These results support a consistent association between pathologic TDP-43, HS, and the development of cognitive impairment in two large studies of brain aging, while the relationship between AD pathology and TDP-43 may vary according to cohort-specific features.

Testamentary Capacity Assessment Tool (TCAT): A Brief Instrument for Patients with Dementia. - Papageorgiou, Sokratis G; Voskou, Panagiota; Economou, Alexandra; Beratis, Ion; Douzenis, Athanasios (J Alzheimers Dis, 2018)
BACKGROUND: In current practice, it is common for the medical practitioner to assess a person's testamentary capacity (TC) and give evidence to the Courts about a potential will contest. TC is an advanced cognitive activity that is both situation- and task-specific. OBJECTIVE: The aim of the present study was the development of a brief, specialized instrument for TC assessment in patients with dementia. METHOD: We developed a short tool consisting of four subtests, assessing the person's core functions which are required for TC: memory (orientation, autobiographical memory and realistic perception of beneficiaries), absence of serious psychopathology, knowledge of financial parameters (value of assets, everyday life products, bills), and intention (vignettes, theory of mind). For its validation, we examined 64 outpatients from the Cognitive Disorders/Dementia Unit, 2nd Department of Behavioral Neurology, University of Athens. The decision of the expert served as the gold standard for the evaluation of TC. RESULTS: Of the 64 participants, 39 were judged by the expert as capable of TC and the remaining 25 as incapable. For the total scale (maximum score of 48), the best combination of sensitivity (82.6%) and specificity (100%) was obtained for a cut-off score of 32/33. Cronbach's alpha showed high levels of internal reliability for the scale (α= 0.86) and the point-biserial correlation coefficients showed high levels of criterion-related validity (rbp = 0.797, p < 0.001). CONCLUSION: The new instrument appears to be a reliable screening tool for the evaluation of TC in dementia, which can be used by both the expert and the non-expert. Further research is needed to confirm these promising findings.
Keywords: Adult; Aged; Cognition Disorders; Dementia; Female; Humans; Male; Memory; Mental Competency; Middle Aged; Neuropsychological Tests; Reproducibility of Results; Sensitivity and Specificity; Wills

Testing Hippocampal Memory in Prodromal Dementia with Lewy Bodies. - Bussè, Cinzia; Caffarra, Paolo; Rossi, Alice; Zorzi, Giovanni; Fragiacomo, Federica; Camporese, Giulia; Pompanin, Sara; Di Bernardo, Gian Antonio; Cagnin, Annachiara (J Alzheimers Dis, 2018)
The Free and Cued Selective Reminding test (FCSRT) was used to assess memory in 19 patients with prodromal dementia with Lewy bodies (DLB) and 25 Alzheimer's disease (AD) patients. DLB scored better than AD in selective measures of the FCSRT: immediate total recall (p = 0.01) and index of sensitivity of cueing (p = 0.001), while free delayed and total memory scores were similarly impaired. The index of sensitivity of cueing held a sensitivity of 76% and specificity of 79% in distinguishing DLB. FCSRT could help in disentangling hippocampal memory deficits from memory impairment due to ineffective recall strategies.

Is There a Characteristic Clinical Profile for Patients with Dementia and Sundown Syndrome? - Angulo Sevilla, David; Carreras Rodríguez, María Teresa; Heredia Rodríguez, Patricia; Fernández Sánchez, Marisa; Vivancos Mora, José Aurelio; Gago-Veiga, Ana Beatriz (J Alzheimers Dis, 2018)
BACKGROUND: Sundown syndrome (SS) is the onset or worsening of behavioral symptoms in the evening in patients with dementia. OBJECTIVE: To identify the differential clinical profile of patients with dementia who present SS. METHODS: A cross-sectional, case-control observational study was conducted by retrospectively reviewing the medical records of patients with dementia in a specialized Memory Unit. We compared the characteristics of patients with and without SS, including sociodemographic variables, etiology, and severity of the dementia, behavioral symptoms, sleep disorders (considering insomnia and hypersomnia), other diseases and treatments employed. We identified the factors related to SS and conducted a logistic regression analysis to establish a predictive nomogram. RESULTS: Of the 216 study patients with dementia, 41 (19%) had SS. There was a predominance of women (2.4:1), advanced age (p = 0.0001), dependence (p < 0.0001), institutionalization (p < 0.0001), caregiver burden (p < 0.0001), anxiety (p < 0.0001), delirium (p < 0.0001), hallucinations (p < 0.0001), wandering (p < 0.0001), Lewy body dementia (p = 0.05), higher Global Deterioration Scale score (GDS; p < 0.0001), and sleep disorders (p < 0.0001). The multivariate analysis revealed that age (p = 0.048), GDS score (p = 0.01), and the presence of insomnia or hypersomnia (p < 0.0001) independently defined the presence of SS. We established a predictive nomogram for developing SS in patients with dementia, with a predictive capacity of 80.1%. CONCLUSION: In our study, age, a higher score on the GDS, and the presence of insomnia or hypersomnia are differential clinical characteristics of patients with SS. We defined a nomogram that helps predicting the occurrence of SS in patients with dementia.

Three Decades of Dementia Research: Insights from One Small Community of Indomitable Rotterdammers. - Wolters, Frank J; Adams, Hieab H H; Bos, Daniel; Licher, Silvan; Ikram, M Arfan (J Alzheimers Dis, 2018)
The most commonly encountered opening sentence in scientific publications about dementia undoubtedly relates to the overwhelming burden of disease. Finding an effective preventive or therapeutic intervention against dementia has been considered the most important unmet need in contemporary medicine. While efforts on tackling this devastating disease have increased exponentially, it is difficult to imagine that in the 1980s and early-1990s, the disease did not feature prominently on any public health report. Yet, it was already then that epidemiologists recognized the growing societal burden of dementia and rationalized that dementia is not necessarily part of aging. Indeed, the conviction that dementia is pathologically distinct from aging led to various efforts in search of unravelling its risk factors and understanding its pre-clinical phase. Among the early pioneers, the population-based Rotterdam Study was initiated in 1990 clearly aiming on chronic diseases including dementia, and among this Alzheimer's disease, as one of its focus points. Ever since, the Rotterdam Study has been an important cornerstone in increasing our knowledge about dementia from an epidemiological perspective. Here, we summarize the main findings originating from this study, and put these into perspective with previous and current work in the field. With an expanding scope of the Rotterdam Study over the years, we discuss findings on occurrence, modifiable risk factors, imaging, and its genetic underpinnings. Importantly, we conclude with recommendations- or, perhaps better stated, a wish list- for future research which may help us reach our finish line: finding an effective preventive or therapeutic intervention against dementia.

Three VCP Mutations in Patients with Frontotemporal Dementia. - Wong, Tsz Hang; Pottier, Cyril; Hondius, David C; Meeter, Lieke H H; van Rooij, Jeroen G J; Melhem, Shami; van Minkelen, Rick; van Duijn, Cornelia M; Rozemuller, Annemieke J M; Seelaar, Harro; Rademakers, Rosa; van Swieten, John C (J Alzheimers Dis, 2018)
Valosin-containing protein (VCP) is involved in multiple cellular activities. Mutations in VCP lead to heterogeneous clinical presentations including inclusion body myopathy with Paget's disease of the bone, frontotemporal dementia and amyotrophic lateral sclerosis, even in patients carrying the same mutation. We screened a cohort of 48 patients with familial frontotemporal dementia (FTD) negative for MAPT, GRN, and C9orf72 mutations for other known FTD genes by using whole exome sequencing. In addition, we carried out targeted sequencing of a cohort of 37 patients with frontotemporal lobar degeneration with Transactive response DNA-binding protein 43 (TDP-43) subtype from the Netherlands Brain bank. Two novel (p.Thr262Ser and p.Arg159Ser) and one reported (p.Met158Val) VCP mutations in three patients with a clinical diagnosis of FTD were identified, and were absence in population-match controls. All three patients presented with behavioral changes, with additional semantic deficits in one. No signs of Paget or muscle disease were observed. Pathological examination of the patient with VCP p.Arg159Ser mutation showed numerous TDP-43 immunoreactive (IR) neuronal intranuclear inclusions (NII) and dystrophic neurites (DN), while a lower number of NII and DN were observed in the patient with the VCP p.Thr262Ser mutation. Pathological findings of both patients were consistent with FTLD-TDP subtype D. Furthermore, only rare VCP-IR NII was observed in both cases. Our study expands the clinical heterogeneity of VCP mutations carriers, and indicates that other additional factors, such as genetic modifiers, may determine the clinical phenotype.

A Three-Factor Structure of Cognitive Functioning Among Unimpaired Carriers and Non-Carriers of Autosomal-Dominant Alzheimer's Disease. - Guzmán-Vélez, Edmarie; Jaimes, Sehily; Aguirre-Acevedo, Daniel C; Norton, Daniel J; Papp, Kathryn V; Amariglio, Rebecca; Rentz, Dorene; Baena, Ana; Henao, Eliana; Tirado, Victoria; Munoz, Claudia; Giraldo, Margarita; et al. (J Alzheimers Dis, 2018)
BACKGROUND: There is a need to find cognitive markers that can help identify individuals at risk for Alzheimer's disease (AD), and that can be used to reliably measure cognitive decline. OBJECTIVE: We tested whether a theoretically driven three-factor structure would characterize cognitive functioning in individuals who are genetically-determined to develop AD due to a mutation in Presenilin-1 (PSEN1) gene. We also examined whether these factors could distinguish cognitively unimpaired PSEN1 mutation carriers from age-matched non-carrier family members. METHODS: 1,395 cognitively unimpaired members of a Colombian kindred with the PSEN1 E280A mutation were included in the study. A confirmatory factor analysis examined the fit of the three-factor model comprising episodic memory (MMSE memory recall, CERAD-COL Word list recall, and Constructional praxis recall), executive function (Phonemic fluency and WCST perseverative errors), and psychomotor processing speed (TMT-A and WAIS-III Digit Symbol). RESULTS: The three-factor model provided an excellent fit for all participants (p = 0.24; RMSEA = 0.01). Further, the episodic memory (p = 0.0004, d = 0.25) and executive functioning (p = 0.001, d = 0.18) factors distinguished cognitively unimpaired carriers from non-carriers. The episodic memory factor provided the earliest indication of preclinical cognitive decline at 35 years of age, nine years before individuals' estimated age of clinical onset. CONCLUSIONS: The three theoretically derived cognitive factors provide a reliable measure of cognition and may be useful for the early detection of AD, as well as for measuring disease progression. However, longitudinal studies are needed to confirm that these factors can be used to track the progression of cognitive decline in preclinical AD.

Time Trends in the Prevalence of Neurocognitive Disorders and Cognitive Impairment in the United States: The Effects of Disease Severity and Improved Ascertainment. - Akushevich, Igor; Yashkin, Arseniy P; Kravchenko, Julia; Ukraintseva, Svetlana; Stallard, Eric; Yashin, Anatoliy I (J Alzheimers Dis, 2018)
BACKGROUND: Trends in the prevalence of cognitive impairment (CI) based on cognitive assessment instruments are often inconsistent with those of neurocognitive disorders (ND) based on Medicare claims records. OBJECTIVE: We hypothesized that improved ascertainment and resulting decrease in disease severity at the time of diagnosis are responsible for this phenomenon. METHODS: Using Medicare data linked to the Health and Retirement Study (1992-2012), we performed a joint analysis of trends in CI and ND to test our hypothesis. RESULTS: We identified two major contributors to the divergent directions in CI and ND trends: reductions in disease severity explained more than 60% of the differences between CI and ND prevalence over the study period; the remaining 40% was explained by a decrease in the fraction of undiagnosed individuals. DISCUSSION: Improvements in the diagnoses of ND diseases were a major contributor to reported trends in ND and CI. Recent forecasts of CI and ND trends in the U.S. may be overly pessimistic.

TLR4 Gene Expression and Pro-Inflammatory Cytokines in Alzheimer's Disease and in Response to Hippocampal Deafferentation in Rodents. - Miron, Justin; Picard, Cynthia; Frappier, Josée; Dea, Doris; Théroux, Louise; Poirier, Judes (J Alzheimers Dis, 2018)
One important aspect in Alzheimer's disease pathology is the presence of chronic inflammation. Considering its role as a key receptor in the microglial innate immune system, TLR4 was shown to regulate the binding and phagocytosis of amyloid plaques by microglia in several mouse models of amyloidosis, as well as the production of pro-inflammatory cytokines. To our knowledge, TLR4 and its association with cytokines have not been thoroughly examined in the brains of subjects affected with Alzheimer's disease. Using quantitative reverse transcription polymerase chain reaction (qRT-PCR) in postmortem human brains, we observed increased expression for the TLR4 and TNF genes (p = 0.001 and p = 0.025, respectively), as well as a trend for higher IL6 gene expression in the frontal cortex of AD subjects when compared to age-matched controls. Similarly, using a mouse model of hippocampal deafferentation without amyloidosis, (i.e., the entorhinal cortex lesioned mouse), we observed significant increases in the expression of both the Tlr4 (p = 0.0367 and p = 0.0193 compared to sham-lesioned mice or to the contralateral side, respectively) and Il1b (p = 0.0055 and p = 0.0066 compared to sham-lesioned mice or to the contralateral side, respectively) genes in the deafferentation phase, but not during the ensuing reinnervation process. In conclusion, we suggest that the modulation of cytokines by TLR4 is differentially regulated whether by the presence of amyloid plaques or by the ongoing deafferentation process.

Tocotrienol-Rich Fraction of Palm Oil Improves Behavioral Impairments and Regulates Metabolic Pathways in AβPP/PS1 Mice. - Durani, Lina Wati; Hamezah, Hamizah Shahirah; Ibrahim, Nor Faeizah; Yanagisawa, Daijiro; Nasaruddin, Muhammad Luqman; Mori, Masaki; Azizan, Kamalrul Azlan; Damanhuri, Hanafi Ahmad; Makpol, Suzana; Wan Ngah, Wan Zurinah; Tooyama, Ikuo (J Alzheimers Dis, 2018)
We have recently shown that the tocotrienol-rich fraction (TRF) of palm oil, a mixture of vitamin E analogs, improves amyloid pathology in vitro and in vivo. However, precise mechanisms remain unknown. In this study, we examined the effects of long-term (10 months) TRF treatment on behavioral impairments and brain metabolites in (15 months old) AβPP/PS1 double transgenic (Tg) Alzheimer's disease (AD) mice. The open field test, Morris water maze, and novel object recognition tasks revealed improved exploratory activity, spatial learning, and recognition memory, respectively, in TRF-treated Tg mice. Brain metabolite profiling of wild-type and Tg mice treated with and without TRF was performed using ultrahigh performance liquid chromatography (UHPLC) coupled to high-resolution accurate mass (HRAM)-orbitrap tandem mass spectrometry (MS/MS). Metabolic pathway analysis found perturbed metabolic pathways that linked to AD. TRF treatment partly ameliorated metabolic perturbations in Tg mouse hippocampus. The mechanism of this pre-emptive activity may occur via modulation of metabolic pathways dependent on Aβ interaction or independent of Aβ interaction.

Total MRI Small Vessel Disease Burden Correlates with Cognitive Performance, Cortical Atrophy, and Network Measures in a Memory Clinic Population. - Banerjee, Gargi; Jang, Hyemin; Kim, Hee Jin; Kim, Sung Tae; Kim, Jae Seung; Lee, Jae Hong; Im, Kiho; Kwon, Hunki; Lee, Jong Min; Na, Duk L; Seo, Sang Won; Werring, David John (J Alzheimers Dis, 2018)
BACKGROUND: Recent evidence suggests that combining individual imaging markers of cerebral small vessel disease (SVD) may more accurately reflect its overall burden and better correlate with clinical measures. OBJECTIVE: We wished to establish the clinical relevance of the total SVD score in a memory clinic population by investigating the association with SVD score and cognitive performance, cortical atrophy, and structural network measures, after adjusting for amyloid-β burden. METHODS: We included 243 patients with amnestic mild cognitive impairment (MCI), Alzheimer's disease dementia, subcortical vascular MCI, or subcortical vascular dementia. All underwent MR and [11C] PiB-PET scanning and had standardized cognitive testing. Multiple linear regression was used to evaluate the relationships between SVD score and cognition, cortical thickness, and structural network measures. Path analyses were performed to evaluate whether network disruption mediates the effects of SVD score on cortical thickness and cognition. RESULTS: Total SVD score was associated with the performance of frontal (β - 4.31, SE 2.09, p = 0.040) and visuospatial (β - 0.95, SE 0.44, p = 0.032) tasks, and with reduced cortical thickness in widespread brain regions. Total SVD score was negatively correlated with nodal efficiency, as well as changes in brain network organization, with evidence of reduced integration and increasing segregation. Path analyses showed that the associations between SVD score and frontal and visuospatial scores were partially mediated by decreases in their corresponding nodal efficiency and cortical thickness. CONCLUSION: Total SVD burden has clinical relevance in a memory clinic population and correlates with cognition, and cortical atrophy, as well as structural network disruption.

Trajectories of Physiological Brain Aging and Related Factors in People Aged from 20 to over-80. - Lee, Jin San; Kim, Seonwoo; Yoo, Heejin; Park, Seongbeom; Jang, Young Kyoung; Kim, Hee Jin; Kim, Ko Woon; Kim, Yeshin; Jang, Hyemin; Park, Key-Chung; Yaffe, Kristine; Yang, Jin-Ju; et al. (J Alzheimers Dis, 2018)
BACKGROUND/OBJECTIVE: In this study, we investigated a long-term trajectory of brain aging (from the 20 s to over-80) in cognitively normal (CN) individuals. We further determined whether differences in sex, education years, and apolipoprotein E ε 4 status affect age-related cortical thinning. METHODS: A total of 2,944 CN individuals who underwent high-resolution (3.0-Tesla) magnetic resonance imaging were included in this study. Cortical thickness was measured using a surface-based method. Multiple linear regression analyses were performed to evaluate age-related cortical thinning and related factors. RESULTS: Compared to those in their 20 s/30 s, participants in their 40 s showed thinning primarily in the medial and lateral frontal and inferior parietal regions, and cortical thinning occurred across most of the cortices with increasing age. Notably, the precuneus, inferior temporal and lateral occipital regions were relatively spared until later in life. Male and lower education years were associated with greater cortical thinning with distinct regional specificity. CONCLUSION: Our findings provide an important clue to understanding the mechanism of age-related cognitive decline and new strategies for preventing the acceleration of pathological brain aging.

Transcranial Sonography in Neurodegenerative Diseases with Cognitive Decline. - Favaretto, Silvia; Walter, Uwe; Baracchini, Claudio; Cagnin, Annachiara (J Alzheimers Dis, 2018)
Transcranial sonography (TCS) of the brain parenchyma detects alterations in the substantia nigra (SN), raphe nuclei and basal ganglia; this technique has been established as a tool for the early diagnosis of Parkinson's disease and differential diagnosis from atypical parkinsonian syndromes. Here, we aimed to review the main applications of TCS in neurodegenerative diseases presenting with dementia syndrome, focusing on Alzheimer's disease (AD), dementia with Lewy bodies (DLB), frontotemporal lobar degeneration, idiopathic normal pressure hydrocephalus, and atypical and secondary parkinsonisms. The finding of bilaterally marked hyperechogenicity of the SN appears as a characteristic feature of DLB, while it is found only in a minority of AD patients. SN hyperechogenicity is also detected in most patients with corticobasal degeneration and in about one third of patients with progressive supranuclear palsy, in which is constantly associated with hyperechogenic alterations of the basal ganglia. In conclusion, TCS is a valid supportive tool in the diagnostic workup of patients with dementia due to different neurodegenerative conditions. A promising new application is the differentiation of DLB from AD even at the early stages of these diseases.
Keywords: Cognition Disorders; Humans; Neurodegenerative Diseases; Ultrasonography, Doppler, Transcranial

Translational Research in Alzheimer's and Prion Diseases. - Di Fede, Giuseppe; Giaccone, Giorgio; Salmona, Mario; Tagliavini, Fabrizio (J Alzheimers Dis, 2018)
Translational neuroscience integrates the knowledge derived by basic neuroscience with the development of new diagnostic and therapeutic tools that may be applied to clinical practice in neurological diseases. This information can be used to improve clinical trial designs and outcomes that will accelerate drug development, and to discover novel biomarkers which can be efficiently employed to early recognize neurological disorders and provide information regarding the effects of drugs on the underlying disease biology. Alzheimer's disease (AD) and prion disease are two classes of neurodegenerative disorders characterized by incomplete knowledge of the molecular mechanisms underlying their occurrence and the lack of valid biomarkers and effective treatments. For these reasons, the design of therapies that prevent or delay the onset, slow the progression, or improve the symptoms associated to these disorders is urgently needed. During the last few decades, translational research provided a framework for advancing development of new diagnostic devices and promising disease-modifying therapies for patients with prion encephalopathies and AD. In this review, we provide present evidence of how supportive can be the translational approach to the study of dementias and show some results of our preclinical studies which have been translated to the clinical application following the 'bed-to-bench-and-back' research model.

Traumatic Brain Injury and Age of Onset of Dementia with Lewy Bodies. - Nguyen, Trung P; Schaffert, Jeff; LoBue, Christian; Womack, Kyle B; Hart, John; Cullum, C Munro (J Alzheimers Dis, 2018)
BACKGROUND: Traumatic brain injury (TBI) with loss of consciousness (LOC) has been associated with earlier onset of mild cognitive impairment, frontotemporal dementia, Parkinson's disease, and Alzheimer's disease (AD), but has not been examined as a risk factor for earlier onset of dementia with Lewy bodies (DLB). OBJECTIVE: The purpose of this study was to assess the association between a history of TBI and the age of onset of DLB. METHOD: Data from 576 subjects with a clinical diagnosis of DLB were obtained from the National Alzheimer's Coordinating Center (NACC). Analyses of Covariance examined whether self-reported history of remote TBI with LOC (i.e., >1 year prior to the first Alzheimer's Disease Center visit) was associated with earlier DLB symptom onset. RESULTS: Controlling for sex, those with a history of remote TBI had an approximately 1.5-year earlier clinician-estimated age of onset (F = 0.87, p = 0.35) and 0.75-years earlier age of diagnosis (F = 0.14, p = 0.71) of DLB compared to those without a history of TBI, though the differences did not reach statistical significance. Analysis of subjects with autopsy-confirmed diagnoses was underpowered due to the low number of TBI+ subjects. CONCLUSIONS: Remote TBI with LOC was not significantly associated with DLB onset, despite being a significant risk factor for cognitive decline and earlier age of onset in other neurodegenerative conditions. Replication of these results using a larger cohort of DLB subjects with and without a TBI history who have undergone autopsy is indicated, as our TBI+ subjects did show a slightly earlier onset of about 1.5 years. Further investigations into other potential DLB risk factors are also warranted.

Treatment of Atrial Fibrillation in Patients with Dementia: A Cohort Study from the Swedish Dementia Registry. - Subic, Ana; Cermakova, Pavla; Religa, Dorota; Han, Shuang; von Euler, Mia; Kåreholt, Ingemar; Johnell, Kristina; Fastbom, Johan; Bognandi, Liselia; Winblad, Bengt; Kramberger, Milica G; Eriksdotter, Maria; et al. (J Alzheimers Dis, 2018)
BACKGROUND: Patients with dementia might have higher risk for hemorrhagic complications with anticoagulant therapy prescribed for atrial fibrillation (AF). OBJECTIVE: This study assesses the risks and benefits of warfarin, antiplatelets, and no treatment in patients with dementia and AF. METHODS: Of 49,792 patients registered in the Swedish Dementia Registry 2007-2014, 8,096 (16%) had a previous diagnosis of AF. Cox proportional hazards models were used to calculate the risk for ischemic stroke (IS), nontraumatic intracranial hemorrhage, any-cause hemorrhage, and death. RESULTS: Out of the 8,096 dementia patients with AF, 2,143 (26%) received warfarin treatment, 2,975 (37%) antiplatelet treatment, and 2,978 (37%) had no antithrombotic treatment at the time of dementia diagnosis. Patients on warfarin had fewer IS than those without treatment (5.2% versus 8.7%; p < 0.001) with no differences compared to antiplatelets. In adjusted analyses, warfarin was associated with a lower risk for IS (HR 0.76, CI 0.59-0.98), while antiplatelets were associated with increased risk (HR 1.25, CI 1.01-1.54) compared to no treatment. For any-cause hemorrhage, there was a higher risk with warfarin (HR 1.28, CI 1.03-1.59) compared to antiplatelets. Warfarin and antiplatelets were associated with a lower risk for death compared to no treatment. CONCLUSIONS: Warfarin treatment in Swedish patients with dementia is associated with lower risk of IS and mortality, and a small increase in any-cause hemorrhage. This study supports the use of warfarin in appropriate cases in patients with dementia. The low percentage of patients on warfarin treatment indicates that further gains in stroke prevention are possible.
Keywords: Aged; Aged, 80 and over; Anticoagulants; Atrial Fibrillation; Dementia; Female; Hemorrhage; Humans; Longitudinal Studies; Male; Registries; Risk Factors; Stroke; Survival Analysis; Sweden; Warfarin

TREM1 mRNA Expression in Leukocytes and Cognitive Function in Japanese Patients with Alzheimer's Disease. - Sao, Tomoko; Yoshino, Yuta; Yamazaki, Kiyohiro; Ozaki, Yuki; Mori, Yoko; Ochi, Shinichiro; Yoshida, Taku; Mori, Takaaki; Iga, Jun-Ichi; Ueno, Shu-Ichi (J Alzheimers Dis, 2018)
BACKGROUND: Triggering receptor expressed on myeloid cells 2 (TREM2) activates the innate immune system, promotes phagocytosis by microglia, and is associated with Alzheimer's disease (AD). The possible role of a related molecule, TREM1, in AD remains unknown. OBJECTIVE: We investigated a possible role for TREM1 in AD by determining the gene expression and methylation levels of TREM1 in leukocytes from AD patients. METHODS: Fifty patients with AD and 50 age-matched healthy controls were enrolled. AD patients underwent a battery of neuropsychiatric tests. Peripheral blood samples were obtained from each participant, RNA and DNA were extracted, and samples were assessed for TREM1 mRNA expression and methylation rates at three CpG sites in the TREM1 promoter. RESULTS: TREM1 mRNA expression levels in AD patients were significantly higher than those in controls (p = 0.008). TREM1 mRNA expression levels were not correlated with sex, age, duration of illness, APOE genotype, donepezil treatment, or scores of most neuropsychiatric tests. TREM1 mRNA expression levels in AD patients were correlated with the total score of the Montgomery-Åsberg Depression Rating Scale (p = 0.047, r = - 0.344). Methylation rates at the three CpG sites were significantly lower in AD patients than in controls. We also found a significant correlation between TREM1 mRNA expression and TREM1 DNA methylation rates (p < 0.001). CONCLUSION: TREM1 may be associated with the immune responses in AD, and along with hypomethylation at CpG sites in the TREM1 promoter, may become part of a biomarker panel for AD pathogenesis.

TRPC1 Null Exacerbates Memory Deficit and Apoptosis Induced by Amyloid-β. - Li, Mengzhu; Liu, Enjie; Zhou, Qiuzhi; Li, Shihong; Wang, Xin; Liu, Yanchao; Wang, Lin; Sun, Dongsheng; Ye, Jinwang; Gao, Yuan; Yang, Xifei; Liu, Jianjun; et al. (J Alzheimers Dis, 2018)
The transient receptor potential cation (TRPC) channels are widely expressed in nervous system but their functions remain largely unclear. Here, we found that TRPC1 deletion did not affect learning and memory in physiological conditions, while it aggravated learning and memory deficits induced by amyloid-β (Aβ), the major component of the senile plaques observed in the brains of Alzheimer's disease (AD). Further studies demonstrated that TRPC1 deletion did not affect cell apoptosis in physiological condition, but it exacerbated the Aβ-induced cell death in mouse hippocampus. Moreover, the level of TRPC1 was decreased in AD cell and mouse models, and upregulation of TRPC1 decreased Aβ levels with attenuation of apoptosis in the cells stably overexpressing amyloid-β protein precursor (AβPP). Finally, the transmembrane domain of TRPC1 could bind to AβPP and thus decreased Aβ production. These findings indicate that loss of TRPC1 exacerbates Aβ-induced memory deficit and cell apoptosis, though it does not impair cognitive function or induce cell death in physiological conditions.

TTC7 and Hyccin Regulate Neuronal Aβ42 Accumulation and its Associated Neural Deficits in Aβ42-Expressing Drosophila. - Sun, Minghao; Zhao, Yinghui; Han, Men; Zhang, Baozhu; Zhang, Xiao; Zhang, Qichao; Lim, Nastasia K-H; Wang, Wen-An; Huang, Fu-De (J Alzheimers Dis, 2018)
Neuronal amyloid-β (Aβ) accumulation plays an important role in the pathogenesis of Alzheimer's disease (AD). The conformation and toxicity of Aβ are regulated by lipids on the plasma membrane. Previously, we found downregulation of Rolling Blackout (RBO) or phosphatidylinositol-4-kinase type IIIα (PI4KIIIα) reduces neuronal Aβ accumulation and associated neural deficits in a Drosophila model expressing Aβ42. In mammals, the homologs of RBO and PI4KIIIα were reported to form a plasma membrane-localized complex with a scaffold protein TTC7 and cytosolic protein Hyccin/FAM126A to tightly control the plasmalemmal level of phosphatidylinositol-4-phosphate. Here, we show genetic downregulation of Drosophila TTC7 and Hyccin also reduces neuronal Aβ accumulation and associated synaptic and motor defects as well as premature death in Aβ42-expressing flies, while overexpression of TTC7 and Hyccin produced the opposite effect. These results, together with our previous study, demonstrate that RBO/TTC7/PI4KIIIα/Hyccin regulate neuronal Aβ accumulation and associated neural deficits in the Drosophila model, further supporting the RBO/Efr3-PI4KIIIα complex as a potential therapeutic target for AD.

Ubisol-Q10 (a Nanomicellar Water-Soluble Formulation of CoQ10) Treatment Inhibits Alzheimer-Type Behavioral and Pathological Symptoms in a Double Transgenic Mouse (TgAPEswe, PSEN1dE9) Model of Alzheimer's Disease. - Muthukumaran, Krithika; Kanwar, Annie; Vegh, Caleb; Marginean, Alexandra; Elliott, Austin; Guilbeault, Nicholas; Badour, Alexander; Sikorska, Marianna; Cohen, Jerome; Pandey, Siyaram (J Alzheimers Dis, 2018)
Alzheimer's disease (AD) is one of the most common neurodegenerative pathologies for which there are no effective therapies to halt disease progression. Given the increase in the incidence of this disorder, there is an urgent need for pharmacological intervention. Unfortunately, recent clinical trials produced disappointing results. Molecular mechanisms of AD are converging on the notion that mitochondrial dysfunction, oxidative stress, and accumulation of dysfunctional proteins are involved in AD pathology. Previously, we have shown that a water-soluble formulation of Coenzyme Q10 (Ubisol-Q10), an integral part of the electron transport chain, stabilizes mitochondria and prevents neuronal cell death caused by neurotoxins or oxidative stress both in vitro and in vivo. In this study, we evaluated the neuroprotective effects of Ubisol-Q10 treatment in double transgenic AD mice. In the present study, we report that providing Ubisol-Q10 in drinking water (at a dose of ∼6 mg/kg/day) reduced circulating amyloid-β (Aβ) peptide, improved long term memory, preserved working spatial memory, and drastically inhibited Aβ plaque formation in 18-month-old transgenic mice compared to an untreated transgenic group. Thus Ubisol-Q10 supplementation has the potential to inhibit the progression of neurodegeneration, leading to a better quality of life for humans suffering with AD.
Keywords: Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Animals; Disease Models, Animal; Male; Maze Learning; Memory; Memory Disorders; Mice; Mice, Transgenic; Microglia; Mutation; Nerve Tissue Proteins; Peptide Fragments; Presenilin-1; Ubiquinone; Vitamins

Underlying Biological Processes in Mild Cognitive Impairment: Amyloidosis Versus Neurodegeneration. - Santana, Isabel; Baldeiras, Ines; Santiago, Beatriz; Duro, Diana; Freitas, Sandra; Pereira, Miguel Tábuas; Almeida, Maria Rosário; Oliveira, Catarina Resende (J Alzheimers Dis, 2018)
The amyloid cascade hypothesis proposes amyloid-β (Aβ) as the earliest and key pathological hallmark of Alzheimer's disease (AD), but this mandatory "amyloid-first pathway" has been contested. Longitudinal studies of mild cognitive impairment (MCI) patients represent an opportunity to investigate the intensity of underlying biological processes (amyloidosis versus neurodegeneration) and their relevance for progression to AD. We re-examined our cohort of amnestic MCI, grouped according to cerebrospinal fluid (CSF) biomarkers, aiming at establishing their prognostic value for Alzheimer-type dementia and testing the hypothetical model of biomarkers sequence, based on the amyloid cascade. Our baseline population consisted of 217 MCI patients, 63% with neurodegeneration markers and 47% with amyloidosis. Within the longitudinal study-group (n = 165), 85 progressed to AD and 80 remained cognitively stable. Age, CSF Aβ42, and t-Tau were identified as the best single predictors of conversion to AD. Regarding MCI classification according to the NIA-AA criteria, the high-AD-likelihood group (HL-both amyloid and neurodegeneration markers) was the most frequent (42%); followed by the Suspected Non-Alzheimer Pathophysiology group (SNAP-26%), the low-AD-likelihood group (LL-negative biomarkers-22%), and the Isolated Amyloid Pathology group (IAP-10%). Risk of progression to AD was higher in HL in relation to the LL group (HR = 6.1, 95% CI = 2.1-18.0, p = 0.001). SNAP and IAP groups were equivalent in terms of risk of progression to AD (IAP: HR = 2.6, 95% CI = 0.7-9.3, p = 0.141; SNAP: HR = 3.1, 95% CI = 1.1-9.6; p = 0.046), but only SNAP was significantly different from the LL group. These results support different neurobiological pathways to AD beyond the amyloid hypothesis, highlighting the alternative "neurodegeneration-first pathway" for further investigation.

Understanding Epigenetics in the Neurodegeneration of Alzheimer's Disease: SAMP8 Mouse Model. - Griñán-Ferré, Christian; Corpas, Rubén; Puigoriol-Illamola, Dolors; Palomera-Ávalos, Verónica; Sanfeliu, Coral; Pallas, Merce (J Alzheimers Dis, 2018)
Epigenetics is emerging as the missing link among genetic inheritance, environmental influences, and body and brain health status. In the brain, specific changes in nucleic acids or their associated proteins in neurons and glial cells might imprint differential patterns of gene activation that will favor either cognitive enhancement or cognitive loss for more than one generation. Furthermore, derangement of age-related epigenetic signaling is appearing as a significant risk factor for illnesses of aging, including neurodegeneration and Alzheimer's disease (AD). In addition, better knowledge of epigenetic mechanisms might provide hints and clues in the triggering and progression of AD. Intense research in experimental models suggests that molecular interventions for modulating epigenetic mechanisms might have therapeutic applications to promote cognitive maintenance through an advanced age. The SAMP8 mouse is a senescence model with AD traits in which the study of epigenetic alterations may unveil epigenetic therapies against the AD.

The Unexpected Role of Aβ1-42 Monomers in the Pathogenesis of Alzheimer's Disease. - Tamagno, Elena; Guglielmotto, Michela; Monteleone, Debora; Manassero, Giusi; Vasciaveo, Valeria; Tabaton, Massimo (J Alzheimers Dis, 2018)
Amyloid-β (Aβ) has been proposed as a biomarker and a drug target for the therapy of Alzheimer's disease (AD). The neurotoxic entity and relevance of each conformational form of Aβ to AD pathology is still under debate; Aβ oligomers are considered the major killer form of the peptide whereas monomers have been proposed to be involved in physiological process. Here we reviewed some different effects mediated by monomers and oligomers on mechanisms involved in AD pathogenesis such as autophagy and tau aggregation. Data reported in this review demonstrate that Aβ monomers could have a major role in sustaining the pathogenesis of AD and that AD therapy should be focused not only in the removal of oligomers but also of monomers.

The Uniform Data Set, Czech Version: Normative Data in Older Adults from an International Perspective. - Nikolai, Tomas; Stepankova, Hana; Kopecek, Miloslav; Sulc, Zdenek; Vyhnálek, Martin; Bezdicek, Ondrej (J Alzheimers Dis, 2018)
BACKGROUND: Outside of the United States, international perspectives on normative data for neuropsychological test performance, within diverse populations, have been scarce. The neuropsychological test battery from the Uniform Data Set (UDS) of the Alzheimer's Disease Centers (ADC) program of the United States National Institute on Aging (NIA) is one of the most sensitive batteries for the evaluation of both normal cognitive aging and pathological cognitive decline. OBJECTIVE: This study aimed to determine the feasibility of the Czech Neuropsychological Test Battery from the Uniform Data Set (UDS-Cz 2.0), while also evaluating the results obtained from an international perspective. METHODS: This paper describes data from 520 cognitively normal participants. Regression analyses were used to describe the influence of demographic variables on UDS-Cz test performance. RESULTS: Cognitive performance on all measures declined with age, with patient education level serving as a protective factor. Therefore, the present study provides normative data for the UDS-Cz, adjusted for the demographic variables of age and education. CONCLUSION: The present study determines the psychometric properties of the UDS-Cz and establishes normative values in the aging Czech population, which can be used in clinical settings.
Keywords: Aged; Aged, 80 and over; Alzheimer Disease; Cognition; Czech Republic; Female; Humans; Internationality; Male; Middle Aged; National Institute on Aging (U.S.); Neuropsychological Tests; Psychometrics; Reference Values; Regression Analysis; United States

Untold New Beginnings: Adult Hippocampal Neurogenesis and Alzheimer's Disease. - Teixeira, Catia M; Pallas-Bazarra, Noemí; Bolós, Marta; Terreros-Roncal, Julia; Avila, Jesús; Llorens-Martín, María (J Alzheimers Dis, 2018)
Neurogenesis occurs in a limited number of brain regions during adulthood. Of these, the hippocampus has attracted great interest due to its involvement in memory processing. Moreover, both the hippocampus and the main area that innervates this structure, namely the entorhinal cortex, show remarkable atrophy in patients with Alzheimer's disease (AD). Adult hippocampal neurogenesis is a process that continuously gives rise to newborn granule neurons in the dentate gyrus. These cells coexist with developmentally generated granule neurons in this structure, and both cooperative and competition phenomena regulate the communication between these two types of cells. Importantly, it has been revealed that GSK-3β and tau proteins, which are two of the main players driving AD pathology, are cornerstones of adult hippocampal neurogenesis regulation. We have shown that alterations either promoting or impeding the actions of these two proteins have detrimental effects on the structural plasticity of granule neurons. Of note, these impairments occur both under basal conditions and in response to detrimental and neuroprotective stimuli. Thus, in order to achieve the full effectiveness of future therapies for AD, we propose that attention be turned toward identifying the pathological and physiological actions of the proteins involved in the pathogenesis of this condition.

Unusual Clinical Presentations Challenging the Early Clinical Diagnosis of Creutzfeldt-Jakob Disease. - Baiardi, Simone; Capellari, Sabina; Bartoletti Stella, Anna; Parchi, Piero (J Alzheimers Dis, 2018)
The introduction of prion RT-QuIC, an ultrasensitive specific assay for the in vivo detection of the abnormal prion protein, has significantly increased the potential for an early and accurate clinical diagnosis of Creutzfeldt-Jakob disease (CJD). However, in the clinical setting, the early identification of patients with possible CJD is often challenging. Indeed, CJD patients may present with isolated symptoms that remain the only clinical manifestation for some time, or with neurological syndromes atypical for CJD. To enhance awareness of unusual disease presentations and promote earlier diagnosis, we reviewed the entire spectrum of atypical early manifestations of CJD, mainly reported to date as case descriptions or small case series. They included sensory either visual or auditory disturbances, seizures, isolated psychiatric manifestations, atypical parkinsonian syndromes (corticobasal syndrome, progressive supranuclear palsy-like), pseudobulbar syndrome, isolated involuntary movements (dystonia, myoclonus, chorea, blepharospasm), acute or subacute onsets mimicking a stroke, isolated aphasia, and neuropathy. Since CJD is a rare disease and its clinical course rapidly progressive, an in-depth understanding and awareness of early clinical features are mandatory to enhance the overall diagnostic accuracy in its very early stages and to recruit optimal candidates for future therapeutic trials.

Update on Vascular Cognitive Impairment Associated with Subcortical Small-Vessel Disease. - Wallin, Anders; Román, Gustavo C; Esiri, Margaret; Kettunen, Petronella; Svensson, Johan; Paraskevas, George P; Kapaki, Elisabeth (J Alzheimers Dis, 2018)
Subcortical small-vessel disease (SSVD) is a disorder well characterized from the clinical, imaging, and neuropathological viewpoints. SSVD is considered the most prevalent ischemic brain disorder, increasing in frequency with age. Vascular risk factors include hypertension, diabetes, hyperlipidemia, elevated homocysteine, and obstructive sleep apnea. Ischemic white matter lesions are the hallmark of SSVD; other pathological lesions include arteriolosclerosis, dilatation of perivascular spaces, venous collagenosis, cerebral amyloid angiopathy, microbleeds, microinfarcts, lacunes, and large infarcts. The pathogenesis of SSVD is incompletely understood but includes endothelial changes and blood-brain barrier alterations involving metalloproteinases, vascular endothelial growth factors, angiotensin II, mindin/spondin, and the mammalian target of rapamycin pathway. Metabolic and genetic conditions may also play a role but hitherto there are few conclusive studies. Clinical diagnosis of SSVD includes early executive dysfunction manifested by impaired capacity to use complex information, to formulate strategies, and to exercise self-control. In comparison with Alzheimer's disease (AD), patients with SSVD show less pronounced episodic memory deficits. Brain imaging has advanced substantially the diagnostic tools for SSVD. With the exception of cortical microinfarcts, all other lesions are well visualized with MRI. Diagnostic biomarkers that separate AD from SSVD include reduction of cerebrospinal fluid amyloid-β (Aβ)42 and of the ratio Aβ42/Aβ40 often with increased total tau levels. However, better markers of small-vessel function of intracerebral blood vessels are needed. The treatment of SSVD remains unsatisfactory other than control of vascular risk factors. There is an urgent need of finding targets to slow down and potentially halt the progression of this prevalent, but often unrecognized, disorder.
Keywords: Animals; Cerebrovascular Disorders; Dementia; Humans

Urine-Based Biomarkers for Alzheimer's Disease Identified Through Coupling Computational and Experimental Methods. - Yao, Fang; Hong, Xiaoyu; Li, Shuiming; Zhang, Yan; Zhao, Qing; Du, Wei; Wang, Yong; Ni, Jiazuan (J Alzheimers Dis, 2018)
Alzheimer's disease (AD) is a chronic neurodegenerative disorder contributing to nearly 70% of dementia cases. However, no diagnostic protein biomarkers are available in urine. In this study, we combined computational and experimental methods to identify urinary biomarkers for AD. First, by analyzing brain tissue-based gene expression data of AD, 2,754 differentially expressed genes were identified, 559 of which were predicted to encode urine-excretory proteins that might act as candidate protein biomarkers of AD. GO enrichment analyses implied that they were mainly involved in microtubule-based process, myelin sheath, and calcium ion binding, suggesting that they might be associated with AD pathogenesis. In order to verify these proteins in urine, an iTRAQ experiment was carried out to analyze urine samples from AD patients and healthy controls, and 15 proteins were detected. Based on the expression changes of these proteins, 4 proteins were chosen for further validation by ELISA experiment, and SPP1, GSN, and IGFBP7 were found to be differentially expressed in the urine of AD patients. After a literature survey, we found that they were involved in AD pathophysiology and might serve as new urine biomarkers for AD. To our knowledge, this is the first time that urine biomarkers for AD were identified by combining computational and experimental methods. Furthermore, this is the first time SPP1, GSN, and IGFBP7 have been reported as potential urine protein biomarkers for AD. Therefore, our findings might provide significant guidance for finding early biomarkers of AD in urine.

The Use of Mobile Games to Assess Cognitive Function of Elderly with and without Cognitive Impairment. - Bonnechère, Bruno; Van Vooren, Mélissa; Bier, Jean-Christophe; De Breucker, Sandra; Van Hove, Olivier; Van Sint Jan, Serge; Feipel, Véronique; Jansen, Bart (J Alzheimers Dis, 2018)
BACKGROUND: In the past few years numerous mobile games have been developed to train the brain. There is a lack of information about the relation between the scores obtained in these games and the cognitive abilities of the patients. OBJECTIVE: The aim of this study was to determine whether or not mobile games can be used to assess cognitive abilities of elderly. METHODS: Twenty healthy young adults, 29 old patients with cognitive impairments (Mini-Mental State Exam (MMSE) [20- 24]) and 27-aged controls participated in this study. Scores obtained in 7 mobile games were correlated with MMSE and the Addenbrooke's Cognitive Evaluation revised (ACE-R). RESULTS: Statistically significant differences were found for all games between patients with cognitive impairments and the aged controls. Correlations between the average scores of the games and the MMSE and ACE-R are significant (R = 0.72 [p < 0.001] and R = 0.81 [p < 0.001], respectively). CONCLUSION: Scores of cognitive mobile games could be used as an alternative to MMSE and ACE-R to evaluate cognitive function of aged people with and without cognitive impairment at least when MMSE is higher than 20/30.

Usefulness of Dual-Point Amyloid PET Scans in Appropriate Use Criteria: A Multicenter Study. - Segovia, Fermín; Gómez-Río, Manuel; Sánchez-Vañó, Raquel; Górriz, Juan Manuel; Ramírez, Javier; Triviño-Ibáñez, Eva; Carnero-Pardo, Cristóbal; Martínez-Lozano, María Dolores; Sopena-Novales, Pablo (J Alzheimers Dis, 2018)
BACKGROUND: Biomarkers of neurodegeneration play a major role in the diagnosis of Alzheimer's disease (AD). Information on both amyloid-β accumulation, e.g., from amyloid positron emission tomography (PET), and downstream neuronal injury, e.g., from 18F-fluorodeoxyglucose (FDG) PET, would ideally be obtained in a single procedure. OBJECTIVE: On the basis that the parallelism between brain perfusion and glucose metabolism is well documented, the objective of this work is to evaluate whether brain perfusion estimated in a dual-point protocol of 18F-florbetaben (FBB) PET can be a surrogate of FDG PET in appropriate use criteria (AUC) for amyloid PET. METHODS: This study included 47 patients fulfilling international AUC for amyloid PET. FDG PET, early FBB (pFBB) PET (0-10 min post injection), and standard FBB (sFBB) PET (90-110 min post injection) scans were acquired. Results of clinical subjective reports and of quantitative region of interest (ROI)-based analyses were compared between procedures using statistical techniques such as Pearson's correlation coefficients and t-tests. RESULTS: pFBB and FDG visual reports on the 47 patients showed good agreement (k  >  0.74); ROI quantitative analysis indicated that both data modalities are highly correlated; and the t-test analysis does not reject the null hypothesis that data from pFBB and FDG examinations comes from independent random samples from normal distributions with equal means and variances. CONCLUSIONS: A good agreement was found between pFBB and FDG data as obtained by subjective visual and quantitative analyses. Dual-point FBB PET scans could offer complementary information (similar to that from FDG PET and FBB PET) in a single procedure, considering pFBB as a surrogate of FDG.

Using Neuropsychological Process Scores to Identify Subtle Cognitive Decline and Predict Progression to Mild Cognitive Impairment. - Thomas, Kelsey R; Edmonds, Emily C; Eppig, Joel; Salmon, David P; Bondi, Mark W (J Alzheimers Dis, 2018)
BACKGROUND: We previously operationally-defined subtle cognitive decline (SCD) in preclinical Alzheimer's disease (AD) using total scores on neuropsychological (NP) tests. NP process scores (i.e., provide information about how a total NP score was achieved) may be a useful tool for identifying early cognitive inefficiencies prior to objective impairment seen in mild cognitive impairment (MCI) and dementia. OBJECTIVE: We aimed to integrate process scores into the SCD definition to identify stages of SCD and improve early detection of those at risk for decline. METHODS: Cognitively "normal" participants from the Alzheimer's Disease Neuroimaging Initiative were classified as "early" SCD (E-SCD; >1 SD below norm-adjusted mean on 2 process scores or on 1 process score plus 1 NP total score), "late" SCD (L-SCD; existing SCD criteria of >1 SD below norm-adjusted mean on 2 NP total scores in different domains), or "no SCD" (NC). Process scores considered in the SCD criteria were word-list intrusion errors, retroactive interference, and learning slope. Cerebrospinal fluid AD biomarkers were used to examine pathologic burden across groups. RESULTS: E-SCD and L-SCD progressed to MCI 2.5-3.4 times faster than the NC group. Survival curves for E-SCD and L-SCD converged at 7-8 years after baseline. The combined (E-SCD+L-SCD) group had improved sensitivity to detect progression to MCI relative to L-SCD only. AD biomarker positivity increased across NC, SCD, and MCI groups. CONCLUSIONS: Process scores can be integrated into the SCD criteria to allow for increased sensitivity and earlier identification of cognitively normal older adults at risk for decline prior to frank impairment on NP total scores.

Utility of Amyloid and FDG-PET in Clinical Practice: Differences Between Secondary and Tertiary Care Memory Units. - Lage, Carmen; Suarez, Andrea Gonzalez; Pozueta, Ana; Riancho, Javier; Kazimierczak, Martha; Bravo, María; Jimenez Bonilla, Julio; de Arcocha Torres, Marıa; Quirce, Remedios; Banzo, Ignacio; Vázquez-Higuera, José Luis; Rabinovici, Gil D; et al. (J Alzheimers Dis, 2018)
The clinical utility of amyloid positron emission tomography (PET) has not been fully established. Our aim was to evaluate the effect of amyloid imaging on clinical decision making in a secondary care unit and compare our results with a previous study in a tertiary center following the same methods. We reviewed retrospectively 151 cognitively impaired patients who underwent amyloid (Pittsburgh compound B [PiB]) PET and were evaluated clinically before and after the scan in a secondary care unit. One hundred and fifty concurrently underwent fluorodeoxyglucose (FDG)-PET. We assessed changes between the pre- and post-PET clinical diagnosis and Alzheimer's disease treatment plan. The association between PiB/FDG results and changes in management was evaluated using χ2 and multivariate logistic regression. Concordance between classification based on scan readings and baseline diagnosis was 66% for PiB and 47% for FDG. The primary diagnosis changed after PET in 17.2% of cases. When examined independently, discordant PiB and discordant FDG were both associated with diagnostic change (p < 0.0001). However, when examined together in a multivariate logistic regression, only discordant PiB remained significant (p = 0.0002). Changes in treatment were associated with concordant PiB (p = 0.009) while FDG had no effect on treatment decisions. Based on our regression model, patients with diagnostic dilemmas, a suspected non-amyloid syndrome, and Clinical Dementia Rating <1 were more likely to benefit from amyloid PET due to a higher likelihood of diagnostic change. We found that changes in diagnosis after PET in our secondary center almost doubled those of our previous analysis of a tertiary unit (9% versus 17.2%). Our results offer some clues about the rational use of amyloid PET in a secondary care memory unit stressing its utility in mild cognitive impairment patients.

Utility of Amyloid PET Scans in the Evaluation of Patients Presenting with Diverse Cognitive Complaints. - Shea, Yat-Fung; Barker, Warren; Greig-Gusto, Maria T; Loewenstein, David A; DeKosky, Steven T; Duara, Ranjan (J Alzheimers Dis, 2018)
BACKGROUND: The impact of amyloid positron emission tomography (Aβ-PET) in a "real-world" memory disorders clinic remains poorly studied. OBJECTIVE: We studied the impact of Aβ-PET in diagnosis and management in the memory clinic and factors making the most impact in diagnosis and management. METHODS: We studied 102 patients who had presented at a memory disorders clinic (the Wien Center for Alzheimer's Disease and Memory Disorders, Miami Beach, FL) and had a diagnostic work-up for cognitive complaints, including Aβ-PET scans. RESULTS: Following Aβ-PET, changes were made in diagnosis (37.3%), in specific treatments for Alzheimer's disease (26.5%) and in psychiatric treatments (25.5%). The agreement between diagnosis pre-Aβ-PET versus post-Aβ-PET diagnosis was only fair, with a Cohen's kappa of 0.23 (95% CI 0-0.42). Patients with MRI findings suggestive of AD (medial temporal and/or parietal atrophy) were more frequently amyloid positive than amyloid negative (66.2% versus 33.8%, p = 0.04). Among patients with atypical clinical features for AD, but with MRI findings suggestive of AD, an amyloid negative PET scan had a greater impact than an amyloid positive PET scan on diagnosis (84.2% versus 17.1%, p < 0.001), management (84.2% versus 40%, p < 0.01) and discussion of results and advice on lifestyle (73.7% versus 22.9%, p < 0.001). CONCLUSIONS: We conclude that MRI features suggestive of AD predict a positive amyloid PET scan. However, among those with MRI features suggestive of AD but with atypical clinical features of AD, the clinical impact on diagnosis and management is greater for an amyloid negative than an amyloid positive Aβ-PET scans.

Utility of an Alzheimer's Disease Risk-Weighted Polygenic Risk Score for Predicting Rates of Cognitive Decline in Preclinical Alzheimer's Disease: A Prospective Longitudinal Study. - Porter, Tenielle; Burnham, Samantha C; Milicic, Lidija; Savage, Greg; Maruff, Paul; Lim, Yen Ying; Li, Qiao-Xin; Ames, David; Masters, Colin L; Rainey-Smith, Stephanie; Rowe, Christopher C; Salvado, Olivier; et al. (J Alzheimers Dis, 2018)
BACKGROUND: With the exception of APOE, genetic variants associated with increased Alzheimer's disease (AD) risk are characterized by small effect sizes. Polygenic risk scores (PRS) have shown utility in predicting AD risk; however, their utility for predicting decline in cognition at preclinical stages of AD is poorly understood. OBJECTIVE: To validate associations of a 22-variant AD-risk-weighted PRS with AD risk and related biomarkers and to assess its utility to predict cognitive decline. METHODS: The PRS was evaluated with respect to brain amyloid-β (Aβ) burden, cerebrospinal fluid (CSF) Aβ42, total-tau, and phospho-tau, and decline in cognition in 643 (570 cognitively normal (CN), 73 AD) PET-imaged participants from the longitudinal Australian Imaging, Biomarkers and Lifestyle (AIBL) Study of Ageing. Cognition was assessed using three composite measures; global cognition, verbal episodic memory, and a Pre-Alzheimer's Cognitive Composite (PACC). RESULTS: PRS, both with and without APOE, were positively correlated with brain Aβ burden, CSF total-tau, and phospho-tau in CN older adults. Further, in CN biomarker positive (Aβhigh) participants, significant associations were observed with baseline and longitudinal cognition. However, this association was not observed after the removal of APOE. Partitioning the PRS into quartiles revealed that the PRS associations with cognitive decline in Aβhigh CN older adults is due to a saturating effect of APOE genotype. CONCLUSIONS: An AD-risk-weighted PRS is associated with cognitive decline in CN older adults. However, this association is absent when APOE genotype is excluded from the PRS, suggesting that associations with cognitive decline in this model of polygenic risk are driven by APOE genotype alone. Further research is needed to define appropriate PRSs with greater utility for predicting preclinical AD cognitive decline.

Utility of the LIBRA Index in Relation to Cognitive Functioning in a Clinical Health Seeking Sample. - Pons, Anke; LaMonica, Haley M; Mowszowski, Loren; Köhler, Sebastian; Deckers, Kay; Naismith, Sharon L (J Alzheimers Dis, 2018)
BACKGROUND: Dementia prevalence is expected to increase substantially over the next few decades. Since there is currently no cure for dementia available, there is an urgent need for the early identification of individuals at high risk for dementia, so that primary and secondary prevention strategies can be implemented. Recently, the LIfestyle for BRAin health (LIBRA) index was developed as a new dementia risk algorithm. It specifically focuses on modifiable risk and protective factors that can be targeted in midlife. OBJECTIVE: The objective of this study was to evaluate the LIBRA index in relation to markers of cognitive functioning in a clinical, health-seeking sample of community-based older adults. METHODS: 484 participants (mean age 62.7 years) were recruited from the Healthy Brain Ageing Clinic at the Brain and Mind Centre, Sydney. Participants underwent comprehensive clinical and neuropsychological assessment and completed a self-report survey pack. Participants were rated via consensus as having either subjective cognitive complaints (SCC) or meeting criteria for mild cognitive impairment (MCI). The LIBRA score was calculated based on 11 available risk and protective factors. RESULTS: 65.4% of the sample met criteria for MCI. People with MCI showed a significantly higher LIBRA score compared to people with SCC. Furthermore, multiple cognitive domains, in particular executive functioning, were associated with a higher LIBRA score, with stronger correlations in people with MCI. CONCLUSION: The LIBRA index might be a useful tool to determine lifestyle-attributable risk of cognitive decline in an older health-seeking population, including people with MCI.

Validation of the Delayed Matching-to-Sample Task 48 (DMS48) in Elderly Chinese. - Feng, Xueyan; Zhou, Aihong; Liu, Zhixin; Li, Fangyu; Wei, Cuibai; Zhang, Guili; Jia, Jianping (J Alzheimers Dis, 2018)
BACKGROUND: Delayed Matching-to-Sample Task 48 (DMS48), a brief tool measuring visual recognition memory, is valid to identify the early stage of Alzheimer's disease (AD) in Caucasians. However, little data is available in Chinese. OBJECTIVE: To develop norms and optimal cutoff points for the DMS48 in Chinese elders. METHODS: A cross-sectional study was conducted in seven memory clinics from five cities across China. DMS48 was applied to 369 Chinese aged 50 or older (138 cognitively normal [CN], 112 mild cognitive impairment due to AD (MCI-A), and 119 mild AD dementia). The demographic factors which influence DMS48 scores were investigated and the norms were established considering those factors. Receiver operating characteristic (ROC) analysis was used to determine the optimal cutoff points. RESULTS: Age was shown to influence DMS48 scores (r = -0.36, p < 0.05), and we presented the age-stratified normative data for the DMS48. The optimal cutoff point is 42/43 for identifying cognitive impairment (MCI-A and AD dementia) against CN (sensitivity 97.80% and specificity 89.13%) and MCI-A against CN (sensitivity 86.60% and specificity 94.20%). A cutoff of 39/40 obtained good sensitivity (100.00%) and specificity (94.90%) in discriminating AD dementia from CN. The age-stratified optimal cutoff points for identifying MCI-A were 43/44 for individuals aged 50 to 59 years old, 42/43 for 60 to 69 years old, 41/42 for 70 to 79 years old, and 40/41 for 80 or older, respectively (sensitivity 84.80% and specificity 95.70%). CONCLUSION: This study proved that DMS48 is of good validation in screening MCI-A in elderly Chinese.
Keywords: Aged; Aged, 80 and over; Alzheimer Disease; China; Cognitive Dysfunction; Cross-Sectional Studies; Female; Humans; Linear Models; Male; Memory Disorders; Middle Aged; Neuropsychological Tests; ROC Curve; Sensitivity and Specificity; Severity of Illness Index

Validation of the Spanish Version of the Dementia Knowledge Assessment Tool 2. - Parra-Anguita, Laura; Moreno-Cámara, Sara; López-Franco, María Dolores; Pancorbo-Hidalgo, Pedro L (J Alzheimers Dis, 2018)
BACKGROUND: There are currently no questionnaires to measure the knowledge of nurses about dementia or Alzheimer's disease care in the Spanish language. OBJECTIVE: To validate the Spanish version of the Dementia Knowledge Assessment Tool 2 (DKAT2-Sp). METHODS: The DKAT2 was translated into Spanish and then back-translated. The new Spanish version was validated in a sample of 361 members of the nursing staff from 24 nursing homes and a sample of 297 nursing students in Spain. Psychometric properties were assessed through an item analysis, a Rasch analysis, differential item functioning analysis, construct validity (known groups), and internal consistency (Cronbach's alpha). RESULTS: The 21 items of the DKAT2-Sp fit the model well, showing a wide range of difficulty. Four items have differential items functioning between nursing professionals and students. The DKAT2-Sp shows acceptable internal consistency (Cronbach's alpha = 0.76 for nursing professionals and 0.83 for students). Scores obtained in the known groups test were as hypothesized (Nursing home staff mean = 15.57 versus Nursing student mean = 12.85; p < 0.0001 for mean difference), supporting construct validity. CONCLUSION: The DKAT2-Sp is a reliable and valid questionnaire to measure knowledge about dementia in both nursing professionals and nursing students in Spanish-speaking contexts.

Vascular Cognitive Impairment and the Gut Microbiota. - Li, Sinian; Shao, Yiming; Li, Kanglan; HuangFu, Changmei; Wang, Wenjie; Liu, Zhou; Cai, Zhiyou; Zhao, Bin (J Alzheimers Dis, 2018)
Vascular cognitive impairment (VCI), the second most common cause of dementia in elderly people, is a term that refers to all forms of cognitive disorders that can be attributed to cerebrovascular disease such as manifestations of discrete infarctions, brain hemorrhages, and white matter lesions. The gut microbiota (GM) has emerged recently as an essential player in the development of VCI. The GM may affect the brain's physiological, behavioral, and cognitive functions through the brain-gut axis via neural, immune, endocrine, and metabolic pathways. Therefore, microbiota dysbiosis may mediate or affect atherosclerosis, cerebrovascular disease, and endothelial dysfunction, which are the predominant risk factors for VCI. Moreover, the composition of the GM includes the bacterial component lipopolysaccharides and their metabolic products including trimethylamine-N-oxide and short-chain fatty acids. These products may increase the permeability of the intestinal epithelium, leading to systemic immune responses, low-grade inflammation, and altered signaling pathways that are associated with the pathogenesis of VCI. In this review, we discuss the proposed mechanisms of the GM in the maintenance of VCI and how it is implicated in acquired metabolic diseases, particularly in VCI regulation.

Vascular Effects on Depressive Symptoms in Cognitive Impairment. - Kim, Yeshin; Jang, Hyemin; Kim, Seung Joo; Cho, Soo Hyun; Kim, Si Eun; Kim, Sung Tae; Kim, Hee Jin; Moon, Seung Hwan; Ewers, Michael; Im, Kiho; Kwon, Hunki; Na, Duk L; et al. (J Alzheimers Dis, 2018)
Late life depression is related to pathologic burdens, such as cerebral small vascular disease (CSVD) and amyloid, which are associated with brain network changes and cortical thinning. To examine the associations of various CSVD imaging markers, amyloid, and network changes with depression in cognitively impaired patients, we prospectively recruited 228 cognitively impaired patients having various degrees of amyloid and CSVD who underwent diffuse tensor image and PiB PET. Greater CSVD burden was associated with greater Geriatric Depression Scale (GDS) (white matter hyperintensities, WMH: p = 0.025, lacunes: p < 0.001) but not with amyloid (p = 0.095), and cortical thinning (p = 0.630) was not associated with greater GDS. The changes in white matter networks were related to GDS with decreasing integration (global efficiency: p < 0.001) and increasing segregation (clustering coefficient: p = 0.009). The network changes mediated the relationships of WMH and lacunes with GDS. Our findings provide insight to better understand how CSVD burdens contribute to depression in cognitively impaired patients having varying degrees of amyloid and vascular burdens.

The Vascular Hypothesis of Alzheimer's Disease: A Key to Preclinical Prediction of Dementia Using Neuroimaging. - de la Torre, Jack (J Alzheimers Dis, 2018)
The vascular hypothesis of Alzheimer's disease (VHAD) was proposed 24 years ago from observations made in our laboratory using aging rats subjected to chronic brain hypoperfusion. In recent years, VHAD has become a mother-lode to numerous neuroimaging studies targeting cerebral hemodynamic changes, particularly brain hypoperfusion in elderly patients at risk of developing Alzheimer's disease (AD). There is a growing consensus among neuroradiologists that brain hypoperfusion is likely involved in the pathogenesis of AD and that disturbed cerebral blood flow (CBF) can serve as a key biomarker for predicting conversion of mild cognitive impairment to AD. The use of cerebral hypoperfusion as a preclinical predictor of AD is becoming decisive in stratifying low and high risk patients that may develop cognitive decline and for assessing the effectiveness of therapeutic interventions. There is currently an international research drive from neuroimaging groups to seek new perspectives that can broaden our understanding of AD and improve lifestyle. Diverse neuroimaging methods are currently being used to monitor normal and dyscognitive brain activity. Some techniques are very powerful and can detect, diagnose, quantify, prognose, and predict cognitive decline before AD onset, even from a healthy cognitive state. Multimodal imaging offers new insights in the treatment and prevention of cognitive decline during advanced aging and better understanding of the functional and structural organization of the human brain. This review discusses the impact the VHAD and CBF are having on the neuroimaging technology that can usher practical strategies to help prevent AD.

VEGFR1 and VEGFR2 in Alzheimer's Disease. - Harris, Rachel; Miners, James Scott; Allen, Shelley; Love, Seth (J Alzheimers Dis, 2018)
Vascular endothelial growth factor (VEGF) is a potent angiogenic factor. Despite upregulation of VEGF in the brain in Alzheimer's disease (AD), probably in response to amyloid-β, vasoconstriction, and tissue hypoxia, there is no consequent increase in microvessel density. VEGF binds to and activates VEGF receptor 2 (VEGFR2), but also binds to VEGF receptor 1 (VEGFR1), which exists in less-active membrane-bound and inactive soluble (sVEGFR1) forms and inhibits pro-angiogenic signaling. We have investigated whether altered expression of VEGF receptors might account for the lack of angiogenic response to VEGF in AD. We assessed the cellular distribution and protein level of VEGFR1 and VEGFR2 in parietal cortex from 50 AD and 36 age-matched control brains, and related the findings to measurements of VEGF and von Willebrand factor level (a marker of microvessel density) in the same tissue samples. VEGFR2 was expressed by neurons, astrocytes and endothelial cells. VEGFR1 was expressed predominantly neuronally and was significantly reduced in AD (p = 0.02). Western blot analysis on a subset of brains showed reduction in VEGFR1:sVEGFR1 in AD (p = 0.046). The lack of angiogenesis despite cerebral hypoperfusion in AD is not explained by altered expression of VEGFR2 or total VEGFR1; indeed, the downregulation of VEGFR1 may represent a pro-angiogenic response to the hypoperfusion. However, the relative increase in sVEGFR1 would be expected to have an anti-angiogenic effect which may be a factor in AD.
Keywords: Aged; Aged, 80 and over; Alzheimer Disease; Brain; Case-Control Studies; Endothelial Cells; Female; Gene Expression Regulation; Humans; Male; Middle Aged; Neovascularization, Pathologic; RNA, Messenger; Signal Transduction; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-1; Vascular Endothelial Growth Factor Receptor-2

Ventral Tegmental Area in Prodromal Alzheimer's Disease: Bridging the Gap between Mice and Humans. - D'Amelio, Marcello; Serra, Laura; Bozzali, Marco (J Alzheimers Dis, 2018)
Alzheimer's disease (AD) is a progressive neurological disorder characterized by several cognitive and non-cognitive symptoms, with episodic memory being the earliest and most prominently impaired cognitive function. Dopaminergic signals are required for encoding hippocampal memory for new events and the ventral tegmental area (VTA), together with the locus coeruleus, are the primary sources of dopamine acting on dopaminergic receptors in the hippocampus. With this in mind, a recent study on a validated mouse model of AD highlighted on the hippocampal dysfunction and its correlation with an early degeneration of dopaminergic neurons in the VTA. In this issue, De Marco and Venneri test the hypothesis that the volume of the VTA nucleus in humans might be associated with cognitive features of AD.

Vestibular Loss Predicts Poorer Spatial Cognition in Patients with Alzheimer's Disease. - Wei, Eric X; Oh, Esther S; Harun, Aisha; Ehrenburg, Matthew; Agrawal, Yuri (J Alzheimers Dis, 2018)
The vestibular system is an important contributor to balance control, spatial orientation, and falls risk. Recent evidence has shown that Alzheimer's disease (AD) patients have a higher prevalence of vestibular impairment relative to healthy controls. We sought to evaluate whether vestibular loss is specifically associated with poor spatial cognitive skills among patients with mild cognitive impairment (MCI) and AD. We enrolled 50 patients (22 MCI and 28 AD) from an interdisciplinary Memory Clinic and measured vestibular physiologic function in all patients. Spatial cognitive function was assessed using the Money Road Map Test (MRMT) and the Trail Making Test Part B (TMT-B). General cognitive function was assessed with the Mini-Mental Status Examination (MMSE). In multivariable linear regression analyses adjusted for age, gender, education level, and MMSE, MCI and AD patients with vestibular loss made significantly more errors on the MRMT relative to patients with normal vestibular function (β= 7.3, 95% CI 2.4, 12.1 for unilateral vestibular loss and β= 6.4, 95% CI 1.9, 10.9 for bilateral vestibular loss). We further stratified AD patients into "spatially normal" and "spatially impaired" groups based on MRMT performance, and found that the prevalence of vestibular loss was significantly higher in the spatially impaired AD group relative to the spatially normal AD group. These findings support the hypothesis that vestibular loss contributes specifically to a decline in spatial cognitive ability in MCI and AD patients, independently of general cognitive decline, and may predict a "spatially impaired" subtype of AD.
Keywords: Aged; Aged, 80 and over; Alzheimer Disease; Bilateral Vestibulopathy; Cognitive Dysfunction; Cross-Sectional Studies; Female; Humans; Linear Models; Male; Multivariate Analysis; Neuropsychological Tests; Prospective Studies; Spatial Navigation; Vestibular Function Tests

Visit-To-Visit Blood Pressure Variability and the Risk of Dementia in Older People. - van Middelaar, Tessa; van Dalen, Jan W; van Gool, Willem A; van den Born, Bert-Jan H; van Vught, Lonneke A; Moll van Charante, Eric P; Richard, Edo (J Alzheimers Dis, 2018)
BACKGROUND: High visit-to-visit variability (VVV) in blood pressure (BP) is associated with cerebrovascular lesions on neuroimaging. OBJECTIVE: Our primary objective was to investigate whether VVV is associated with incident all-cause dementia. As a secondary objective, we studied the association of VVV with cognitive decline and cardiovascular disease (CVD). METHODS: We included community-dwelling people (age 70-78 year) from the 'Prevention of Dementia by Intensive Vascular Care' (preDIVA) trial with three to five 2-yearly BP measurements during 6-8 years follow-up. VVV was defined using coefficient of variation (CV; SD/mean×100). Cognitive decline was assessed using the Mini-Mental State Examination (MMSE). Incident CVD was defined as myocardial infarction or stroke. We used a Cox proportional hazard regression and mixed-effects model adjusted for sociodemographic factors and cardiovascular risk factors. RESULTS: In 2,305 participants (aged 74.2±2.5), mean systolic BP over all available visits was 150.1 mmHg (SD 13.6), yielding a CV of 9.0. After 6.4 years (SD 0.8) follow-up, 110 (4.8%) participants developed dementia and 140 (6.1%) CVD. Higher VVV was not associated with increased risk of dementia (hazard ratio [HR] 1.00 per point CV increase; 95% confidence interval [CI] 0.96-1.05), although the highest quartile of VVV was associated with stronger decline in MMSE (β -0.09, 95% CI -0.17 to -0.01). Higher VVV was associated with incident CVD (HR 1.07; 95% CI 1.04-1.11). CONCLUSION: In our study among older people, high VVV is not associated with incident all-cause dementia. It is associated with decline in MMSE and incident CVD.
Keywords: Aged; Antihypertensive Agents; Blood Pressure; Cardiovascular Diseases; Dementia; Female; Humans; Hypertension; Incidence; Male; Netherlands; Proportional Hazards Models; Risk Factors

Visual Processing during Short-Term Memory Binding in Mild Alzheimer's Disease. - Fernández, Gerardo; Orozco, David; Agamennoni, Osvaldo; Schumacher, Marcela; Sañudo, Silvana; Biondi, Juan; Parra, Mario A (J Alzheimers Dis, 2018)
Patients with Alzheimer's disease (AD) typically present with attentional and oculomotor abnormalities that can have an impact on visual processing and associated cognitive functions. Over the last few years, we have witnessed a shift toward the analyses of eye movement behaviors as a means to further our understanding of the pathophysiology of common disorders such as AD. However, little work has been done to unveil the link between eye moment abnormalities and poor performance on cognitive tasks known to be markers for AD patients, such as the short-term memory-binding task. We analyzed eye movement fixation behaviors of thirteen healthy older adults (Controls) and thirteen patients with probable mild AD while they performed the visual short-term memory binding task. The short-term memory binding task asks participants to detect changes across two consecutive arrays of two bicolored object whose features (i.e., colors) have to be remembered separately (i.e., Unbound Colors), or combined within integrated objects (i.e., Bound Colors). Patients with mild AD showed the well-known pattern of selective memory binding impairments. This was accompanied by significant impairments in their eye movements only when they processed Bound Colors. Patients with mild AD remarkably decreased their mean gaze duration during the encoding of color-color bindings. These findings open new windows of research into the pathophysiological mechanisms of memory deficits in AD patients and the link between its phenotypic expressions (i.e., oculomotor and cognitive disorders). We discuss these findings considering current trends regarding clinical assessment, neural correlates, and potential avenues for robust biomarkers.

Visual Processing of Emotional Faces is Preserved in Mild Cognitive Impairment. - McCade, Donna L; Guastella, Adam J; Chen, Nigel T M; Lewis, Simon J G; Naismith, Sharon L (J Alzheimers Dis, 2018)
BACKGROUND: Research suggests that deficits in emotion recognition are evident in individuals with amnestic mild cognitive impairment (aMCI), a group 'at risk' of developing dementia. The mechanisms underlying this deficit, however, are unclear. OBJECTIVE: In this study, we sought to determine whether there are alterations in the way in which individuals with MCI visually explore emotional facial stimuli. METHODS: Eighteen healthy older controls (mean age = 64.6 years) and 32 individuals with MCI were recruited including 18 with the non-amnestic multiple domain (naMCI-md) subtype (mean age = 63.8 years) and 14 with the amnestic multiple domain (aMCI-md) subtype (mean age = 67.9 years). All participants were given a novel eye-tracking paradigm to investigate eye gaze while viewing images of emotional faces on a computer screen. RESULTS: Analyses of eye gaze revealed no significant difference in the percentage of time that groups spent fixating on facial and peripheral facial regions when viewing emotional faces. All participants showed a relative preference for the eye region of faces relative to all other regions. Individuals with aMCI-md were found to be less accurate than controls and naMCI-md on emotion recognition measures. For naMCI-md individuals, significant relationships were found between efficiencies in visual scanning and increased fixation time on the eye region. CONCLUSIONS: Visual processing strategies adopted by aMCI-md individuals when exploring emotional faces do not significantly differ from those of healthy controls or naMCI-md individuals. This suggests that impaired facial emotion recognition in aMCI-md is not likely accounted for by visual processing differences, but rather may reflect an eroded ability to extract meaningful cues from the eye region.

Visualization of Focal Thinning of the Ganglion Cell-Inner Plexiform Layer in Patients with Mild Cognitive Impairment and Alzheimer's Disease. - Shao, Yi; Jiang, Hong; Wei, Yantao; Shi, Yingying; Shi, Ce; Wright, Clinton B; Sun, Xiaoyan; Vanner, Elizabeth A; Rodriguez, Anny D; Lam, Byron L; Rundek, Tatjana; Baumel, Barry S; et al. (J Alzheimers Dis, 2018)
BACKGROUND: A detailed analysis of the tomographic thickness of intraretinal layers may provide more information on neurodegeneration in patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). OBJECTIVE: The goal was to analyze tomographic thickness patterns of intraretinal layers in patients with AD andMCI. METHOD: Forty-nine patients (25 AD and 24 MCI) and 21 cognitively normal (CN) controls were imaged using ultra-high-resolution optical coherence tomography to obtain volumetric data centered on the fovea. The segmented intraretinal layers were retinal nerve fiber layer (RNFL), ganglion cell- inner plexiform layer (GCIPL), inner nuclear layer (INL), outer nuclear layer (ONL), outer plexiform layer (OPL), and retinal photoreceptor (PR), in addition to the total retinal thickness(TRT). RESULTS: The thickness differences were negative (thinning) mainly in TRT, RNFL, and GCIPL in both AD and MCI groups in comparison to CN, while the thickness differences were positive (thickening) mainly in ONL and PR in AD. GCIPL of AD and MCI was thinner in superior, nasal superior, and temporal superior quadrants, compared to CN (p < 0.05). GCIPL of the inner superior, inner nasal superior, inner temporal superior, and outer nasal superior sectors was significantly thinner in AD than CN (p < 0.05). GCIPL of the outer superior, inner temporal superior, outer nasal, and temporal superior sectors was significantly thinner in MCI than CN (p < 0.05). CONCLUSION: Focal thinning of the GCIPL was visualized and quantified by detailed partitions in AD and MCI, which provides specific information about neurodegeneration in MCI and AD.

Volume and Connectivity of the Ventral Tegmental Area are Linked to Neurocognitive Signatures of Alzheimer's Disease in Humans. - De Marco, Matteo; Venneri, Annalena (J Alzheimers Dis, 2018)
BACKGROUND: There is an urgent need to identify the earliest biological changes within the neuropathological cascade of Alzheimer's disease (AD) processes. Recent findings in a murine model of AD showed significant preclinical loss of dopaminergic neurons in the ventral tegmental area (VTA), accompanied by reduced hippocampal innervation and declining memory. It is unknown if these observations can be translated in humans. OBJECTIVE: We tested the hypothesis that VTA volume is associated with the typical clinical markers of AD in a cohort of patients and healthy controls. METHODS: Structural and resting state functional MRI scans, and neuropsychological scores were acquired for 51 healthy adults, 30 patients with a diagnosis of mild cognitive impairment, and 29 patients with a diagnosis of AD dementia. VTA volume was quantified together with other control nuclei. The association between nuclei volume, hippocampal size, memory performance, and linguistic-executive skills was tested. The effect of VTA functional connectivity was also tested. RESULTS: VTA size, but not of control nuclei, yielded a strong association with both hippocampal size and memory competence (but not linguistic-executive performance), and this was particularly strong in healthy adults. In addition, functional connectivity between the VTA and hippocampus was significantly associated with both markers of AD. CONCLUSION: Diminished dopaminergic VTA activity may be crucial for the earliest pathological features of AD and might suggest new strategies for early treatment. Memory encoding processes may represent cognitive operations susceptible to VTA neurodegeneration.

Voxel-Based Acetylcholinesterase PET Study in Early and Late Onset Alzheimer's Disease. - Hirano, Shigeki; Shinotoh, Hitoshi; Shimada, Hitoshi; Ota, Tsuneyoshi; Sato, Koichi; Tanaka, Noriko; Zhang, Ming-Rong; Higuchi, Makoto; Fukushi, Kiyoshi; Irie, Toshiaki; Kuwabara, Satoshi; Suhara, Tetsuya (J Alzheimers Dis, 2018)
BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disorder characterized by chronic progressive cognitive decline and displays underlying brain cholinergic dysfunction, providing a rationale for treatment with cholinomimetic medication. The clinical presentations and courses of AD patients may differ by age of onset. OBJECTIVE: The objective of the present study was to illustrate the regional differences of brain acetylcholinesterase (AChE) activity as quantified by N-[11C]methylpiperidinyl-4-acetate ([11C]MP4A) and PET using parametric whole brain analysis and clarify those differences as a function of age. METHODS: 22 early onset AD (EOAD) with age at onset under 65, the remaining 26 as late onset AD (LOAD), and 16 healthy controls (HC) were enrolled. Voxel-based AChE activity estimation of [11C]MP4A PET images was conducted by arterial input and unconstrained nonlinear least-squares method with subsequent parametrical analyses. Statistical threshold was set as Family Wise Error corrected, p-value <0.05 on cluster-level and cluster extent over 30 voxels. RESULTS: Voxel-based group comparison showed that, compared to HC, both EOAD and LOAD showed cortical AChE decrement in parietal, temporal, and occipital cortices, with wider and stringent cortical involvement in the EOAD group, most prominently demonstrated in the temporal region. There was no significant correlation between age and regional cerebral AChE activity except for a small left superior temporal region in the AD group (Brodmann's area 22, Zmax = 5.13, 396 voxels), whereas no significant cluster was found in the HC counterpart. CONCLUSION: Difference in cortical cholinergic dysfunction between EOAD and LOAD may shed some light on the cholinomimetic drug efficacy in AD.

Walnut Supplementation in the Diet Reduces Oxidative Damage and Improves Antioxidant Status in Transgenic Mouse Model of Alzheimer's Disease. - Pandareesh, Mirazkar D; Chauhan, Ved; Chauhan, Abha (J Alzheimers Dis, 2018)
Our previous study has shown beneficial effects of walnuts on memory and learning skills in transgenic mouse model of Alzheimer's disease (AD-tg). To understand underlying mechanism, we studied here whether walnuts can reduce oxidative stress in AD. From 4 months of age, experimental AD-tg mice were fed diets containing 6% (T6) or 9% walnuts (T9) (equivalent to 1 or 1.5 oz, of walnuts per day in humans) for 5, 10, or 15 months. The control groups, i.e., AD-tg (T0) and wild-type (Wt) mice, were fed diets without walnuts. Free radicals, i.e., reactive oxygen species (ROS), lipid peroxidation, protein oxidation, and antioxidant enzymes were assessed in these mice at different ages. AD-tg mice on control diet (T0) showed significant age-dependent increase in ROS levels, lipid peroxidation, and protein oxidation coupled with impaired activities of antioxidant enzymes [superoxide dismutase, catalase, and glutathione peroxidase] compared to Wt mice. Oxidative stress was significantly reduced in AD-tg mice on diets with walnuts (T6, T9), as evidenced by decreased levels of ROS, lipid peroxidation, and protein oxidation, as well as by enhanced activities of antioxidant enzymes compared to T0 mice. Long-term supplementation with walnuts for 10 or 15 months was more effective in reducing oxidative stress in AD-tg mice. Our findings indicate that walnuts can reduce oxidative stress, not only by scavenging free radicals, but also by protecting antioxidant status, thus leading to reduced oxidative damage to lipids and proteins in AD. Therefore, by reducing oxidative stress, a walnut-enriched diet may help reduce the risk or delay the onset and progression of AD.

What Do We Know About Behavioral Crises in Dementia? A Systematic Review. - Backhouse, Tamara; Camino, Julieta; Mioshi, Eneida (J Alzheimers Dis, 2018)
BACKGROUND: Behavioral crises in dementia are represented by a wide variety of symptoms, regularly require external intervention from professionals, and are reported as a risk factor for hospital admission. Little is known about the factors that are associated with them. OBJECTIVE: To determine the factors associated with dementia-related behavioral crises. METHODS: We searched MEDLINE, CINAHL, PsycINFO, EMBASE, and AMED databases. An additional lateral search including reference lists was conducted. Two researchers screened all records for potential eligibility. Narrative synthesis was used to bring together the findings. RESULTS: Out of the 5,544 records identified, 24 articles (18 distinct studies) met the eligibility criteria. Aggression and agitation were the most common behaviors present at crises. Delusions, wandering/absconding, and hallucinations were also key behaviors contributing to crises. Behavioral crises predominantly happened in the severe stages of dementia (according to MMSE scores), in people with dementia residing in their own homes and in long-term care, and were the catalyst for admissions to psychiatric inpatient settings, specialist-care units, long-term care settings, or for referrals to psychiatric community services. Lack of consistency in assessment of behavior, and management of agitation/aggression in dementia crises were evident. CONCLUSION: Interventions to reduce the likelihood of people with dementia-related behaviors reaching crisis point need to focus on both family and care home settings and incorporate aggression and agitation management. Future research should focus on determining the factors that could be addressed to prevent behavioral crises and the interventions and models of care that may help to prevent crises.

What Factors Predict Family Caregivers' Attendance at Dementia Cafés? - Jones, Susan May; Killett, Anne; Mioshi, Eneida (J Alzheimers Dis, 2018)
BACKGROUND: Dementia Cafés are community support groups which provide post-diagnostic support for families affected by dementia. However, little is known about the characteristics of caregivers who attend Cafés. OBJECTIVES: To describe the demographic and psychosocial characteristics of caregivers who attend Dementia Cafés, and to identify which of those factors may influence the likelihood of family caregivers attending Dementia Cafés. METHODS: A cross-sectional study on caregivers (n = 80; July 2016- July 2017). Resilience (Brief Resilient Coping Scale), Subjective Wellbeing (Personal Wellbeing Index), and Social Support (MOS-Social Support Survey) were measured. Café attendees and non-attendees were compared in regards to demographic characteristics (Chi-Square tests), resilience, subjective wellbeing and social support (independent t-tests). Bivariate and multivariate regression analyses were run to detect associations between predictor variables and café attendance. RESULTS: Caregivers who attended Cafés reported higher resilience (OR: 1.26; 95% CI 1.10-1.45; p = 0.001) and subjective wellbeing (OR: 1.63; 95% CI 1.24-2.142; p = 0.001); no significant difference in social support was detected. Female caregivers were more likely to attend a Café (OR: 3.23; 95% CI 1.14-9.10; p = 0.03). However, only higher subjective wellbeing (OR: 1.63; 95% CI 1.10-24.2; p = 0.02) and fewer years formal education (OR: 4.99; 95% CI 1.12-21.36; p = 0.03) predicted attendance at a café. CONCLUSION: Dementia Cafés may bring about benefits in resilience and subjective wellbeing, or may be best suited to those with higher resilience and wellbeing. Cafes are not being accessed by all caregiver groups. Alternative models of post-diagnostic support should be considered to increase equity of care.

When Art Meets Gardens: Does It Enhance the Benefits? The Nancy Hypothesis of Care for Persons with Alzheimer's Disease. - Jonveaux, Thérèse Rivasseau; Fescharek, Reinhard (J Alzheimers Dis, 2018)
The creation of healing gardens for persons with Alzheimer's disease and related diseases (ADRD) offers vast potential. They can play a role in the scaffolding of cognitive disorders, emotional stress, sensory processing, sense of harmony, and appeasement. These effects are achieved through a distributed interplay of psychological functions with the immediate environment and local culture on the one hand, and dialogue on the other. The garden, a natural canvas created by man, shares with art the ability to foster an esthetic sense for which the perception can be measured by functional neurological imaging exploration. Art represents a mediator for the collaborative realization of distributed psychological functions between different individuals. Based on the hypothesis of an optimization of the therapeutic potential of a garden by a design adapted to the neuro-psycho-social and cultural specificities of its users combined with the thoughtful introduction of an artistic dimension, the "art, memory and life" healing garden was created at the University Hospital of Nancy as a prototype for persons with ADRD. The design concept was based on two hypotheses that we formulate herein, discuss their theoretical foundation, and suggest enhanced design for therapeutic gardens based upon our experience.
Keywords: Alzheimer Disease; Art Therapy; Cognition; Cognitive Behavioral Therapy; France; Gardening; Humans

Which Risk Factors Causally Influence Dementia? A Systematic Review of Mendelian Randomization Studies. - Kuźma, Elżbieta; Hannon, Eilis; Zhou, Ang; Lourida, Ilianna; Bethel, Alison; Levine, Deborah A; Lunnon, Katie; Thompson-Coon, Jo; Hyppönen, Elina; Llewellyn, David J (J Alzheimers Dis, 2018)
BACKGROUND: Numerous risk factors for dementia are well established, though the causal nature of these associations remains unclear. OBJECTIVE: To systematically review Mendelian randomization (MR) studies investigating causal relationships between risk factors and global cognitive function or dementia. METHODS: We searched five databases from inception to February 2017 and conducted citation searches including MR studies investigating the association between any risk factor and global cognitive function, all-cause dementia or dementia subtypes. Two reviewers independently assessed titles and abstracts, full-texts, and study quality. RESULTS: We included 18 MR studies investigating education, lifestyle factors, cardiovascular factors and related biomarkers, diabetes related and other endocrine factors, and telomere length. Studies were of predominantly good quality, however eight received low ratings for sample size and statistical power. The most convincing causal evidence was found for an association of shorter telomeres with increased risk of Alzheimer's disease (AD). Causal evidence was weaker for smoking quantity, vitamin D, homocysteine, systolic blood pressure, fasting glucose, insulin sensitivity, and high-density lipoprotein cholesterol. Well-replicated associations were not present for most exposures and we cannot fully discount survival and diagnostic bias, or the potential for pleiotropic effects. CONCLUSIONS: Genetic evidence supported a causal association between telomere length and AD, whereas limited evidence for other risk factors was largely inconclusive with tentative evidence for smoking quantity, vitamin D, homocysteine, and selected metabolic markers. The lack of stronger evidence for other risk factors may reflect insufficient statistical power. Larger well-designed MR studies would therefore help establish the causal status of these dementia risk factors.

White Matter and Cognition in Traumatic Brain Injury. - Filley, Christopher M; Kelly, James P (J Alzheimers Dis, 2018)
Traumatic brain injury (TBI) is a leading cause of disability and produces a wide range of cognitive, emotional, and physical consequences. The impact of TBI on cognition is among the most important questions in this field but remains incompletely understood. The immediate cognitive effects of concussion, while usually short-lived, may be profound and lasting in some individuals, and long-term sequelae of TBI may include dementia of several varieties including post-traumatic leukoencephalopathy, chronic traumatic encephalopathy, and Alzheimer's disease. Whereas the etiopathogenesis of cognitive dysfunction after TBI remains uncertain, a reasonable point to begin is a focus on the white matter of the brain, where the neuropathological lesion known as diffuse axonal injury (DAI) is routinely identified. White matter is not typically accorded the significance granted to cortical gray matter in discussions of cognitive dysfunction and dementia, but increasing evidence is accumulating to suggest that cognitive decline after TBI is a direct result of white matter injury, and that lesions in this brain component are crucial in the sequence of events leading ultimately to dementia of several types. In this review, we consider the topic of white matter and cognition in TBI, beginning with DAI and proceeding to the role of inflammation in the pathogenesis of cognitive dysfunction and dementia that can follow. A brief review of possible therapeutic options will also be offered, including the use of anti-inflammatory agents and the exploitation of white matter plasticity, to treat acute and post-acute injuries, and lower the incidence of dementia resulting from TBI.

White Matter Hyperintensities and Cognition in Mild Cognitive Impairment and Alzheimer's Disease: A Domain-Specific Meta-Analysis. - van den Berg, Esther; Geerlings, Mirjam I; Biessels, Geert Jan; Nederkoorn, Paul J; Kloppenborg, Raoul P (J Alzheimers Dis, 2018)
BACKGROUND: White matter hyperintensities (WMHs) are related to cognitive dysfunction in the general population. The clinical relevance of WMHs in patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) is, however, unclear. OBJECTIVE: This meta-analysis aimed to quantify the association of WMHs and specific cognitive domains in patients with MCI or AD. METHODS: PubMed (January 1990-January 2017) was searched for studies that used MRI to quantify WMHs, and measured cognitive functioning (≥1 predefined cognitive domain with ≥1 test) in a well-defined population of persons diagnosed with MCI or AD. Fischer's Z was used as the common metric for effect size. Modifying effects of demographics, MMSE, and WMH location were examined. RESULTS: Twelve cross-sectional studies on AD (total n = 1,370, median age 75 years) and 10 studies on MCI (9 cross-sectional, 1 longitudinal; total n = 2,286, median age 73 years) were included. The association between WMHs and overall cognition was significantly stronger for MCI (-0.25, -0.36 to -0.14) than for AD (-0.11, -0.14 to -0.08; QM = 10.7, p < 0.05). For both groups, largest effect sizes were found in attention and executive functions (-0.26, -0.36 to -0.15) and processing speed (-0.21, -0.35 to -0.12). No significant modifying effects of age and gender were found. CONCLUSION: WMHs have a medium-sized association with different cognitive functions in patients with MCI and a small, but statistically significant, association with cognition in AD. These result underscore the role of co-occurring vascular brain damage in MCI and AD.

White Matter Hyperintensity Predicts the Risk of Incident Cognitive Decline in Community Dwelling Elderly. - Ding, Ding; Xiong, Yunyun; Zhao, Qianhua; Guo, Qihao; Chu, Shuguang; Chu, Winnie W C; Luo, Jianfeng; Liang, Xiaoniu; Zheng, Li; Hong, Zhen; Wong, Lawrence K S; Mok, Vincent C T (J Alzheimers Dis, 2018)
BACKGROUND: Unlike western countries, data on white matter hyperintensity (WMH) in community dwelling elderly in Asian population is very limited. OBJECTIVE: To examine the relation between baseline WMH burden and the risk of incident cognitive decline in a community-based cohort with Chinese-dwelling elderly. METHODS: We prospectively evaluated the incident cognitive decline for 226 participants in the Shanghai Aging Study. Baseline WMH severity was visually rated by the age-related white matter changes (ARWMC) scale based on MRI. Cox proportional hazards regression model was used to estimate the relative risk (RR) of total ARWMC scale, global ARWMC score, presence of lacune and microbleed, for incident cognitive decline by adjusting potential confounders. RESULTS: Forty subjects were identified with incident cognitive decline (new onset 34 mild cognitive impairment and 6 dementia) during a median duration of 6 years follow-up. The incidence of cognitive decline was 3.0 (95% confidence interval [CI] 2.2-4.1) per 100 person-years. Increasing total ARWMC scale [RR1.21 (95% CI 1.06-1.39), p = 0.004)], confluent WMH [RR3.16 (95% CI 1.50-6.64), p = 0.002), and presence of lacunes [RR 2.73 (95% CI 1.21-6.15)] at baseline were independent predictors of incident cognitive decline. CONCLUSION: Our study demonstrated that confluent WMH may increase the risk of incident cognitive decline by 3 folds in community dwelling subjects. Small vessel disease may cause heavy burden of cognitive impairment in the elderly in China.
Keywords: Aged; China; Cognitive Dysfunction; Female; Humans; Independent Living; Kaplan-Meier Estimate; Magnetic Resonance Imaging; Male; Middle Aged; Neuropsychological Tests; Proportional Hazards Models; Prospective Studies; Risk Factors; White Matter

Word and Picture Version of the Free and Cued Selective Reminding Test (FCSRT): Is There Any Difference? - Arighi, Andrea; Carandini, Tiziana; Mercurio, Matteo; Carpani, Giovanni; Pietroboni, Anna Margherita; Fumagalli, Giorgio; Ghezzi, Laura; Basilico, Paola; Calvi, Alberto; Scarioni, Marta; De Riz, Milena; Fenoglio, Chiara; et al. (J Alzheimers Dis, 2018)
The Free and Cued Selective Reminding Test (FCSRT) is the most commonly used neuropsychological test to evaluate episodic memory. Two variants of FCSRT exist, using the recall of words (FCSRT-w) or pictures (FCSRT-p). Fourteen patients with mild cognitive impairment underwent neuropsychological evaluation and brain magnetic resonance. We found differences in FCSRT-w and FCSRT-p variants scores. FCSRT-p was correlated with atrophy in areas involved in visual stimuli processing while FCSRT-w was correlated to hippocampal atrophy. Our study suggests that FCSRT-w and FCSRT-p scores are not equivalent, but a larger cohort of patients is needed to validate these results.
Keywords: Aged; Aged, 80 and over; Association Learning; Cognitive Dysfunction; Cues; Female; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Mental Recall; Middle Aged; Neuropsychological Tests; Photic Stimulation; Vocabulary

Zinc Exacerbates Tau Pathology in a Tau Mouse Model. - Craven, Kristen M; Kochen, William R; Hernandez, Carlos M; Flinn, Jane M (J Alzheimers Dis, 2018)
Hyperphosphorylated tau protein is a key pathology in Alzheimer's disease (AD), frontotemporal dementia, chronic traumatic encephalopathy, and Parkinson's disease. The essential trace element zinc exacerbates tauopathy in vitro as well as in a Drosophila model of AD. However, the interaction has never been assessed behaviorally or biochemically in mammals. Zinc supplementation is prevalent in society, finding use as a treatment for macular degeneration and cataracts, and is also taken as an immune system booster with high levels appearing in multivitamins marketed toward the elderly. Using a transgenic mouse model that contains the human gene for tau protein (P301L), we assessed the effects of excess chronic zinc supplementation on tau pathology. Behavioral tests included nest building, circadian rhythm, Morris Water Maze, fear conditioning, and open field. Biochemically, total tau and Ser396 phosphorylation were assessed using western blot. Number of tangles were assessed by Thioflavin-S and free zinc levels were assessed by Zinpyr-1. Tau mice demonstrated behavioral deficits compared to control mice. Zinc supplementation exacerbated tauopathic deficits in circadian rhythm, nesting behavior, and Morris Water Maze. Biochemically, zinc-supplemented tau mice showed increased phosphorylation at pSer396. Zinc supplementation in tau mice also increased tangle numbers in the hippocampus while decreasing free-zinc levels, demonstrating that tangles were sequestering zinc. These results show that zinc intensified the deficits in behavior and biochemistry caused by tau.

18F-AV-1451 PET Imaging in Three Patients with Probable Cerebral Amyloid Angiopathy. - Kim, Hee Jin; Cho, Hanna; Werring, David J; Jang, Young Kyoung; Kim, Yeo Jin; Lee, Jin San; Lee, Juyoun; Jun, Soomin; Park, Seongbeom; Ryu, Young Hoon; Choi, Jae Yong; Cho, Young Seok; et al. (J Alzheimers Dis, 2017)
Cerebrovascular deposition of amyloid-β, known as cerebral amyloid angiopathy (CAA), is associated with MRI findings of lobar hemorrhage, cerebral microbleeds, and cortical superficial siderosis. Although pathological studies suggest that tau may co-localize with vascular amyloid, this has not yet been investigated in CAA in vivo. Three patients with probable CAA underwent 11C-Pittsburgh Compound B (PiB) PET or 18F-florbetaben PET to evaluate amyloid burden, and 18F-AV-1451 PET to evaluate paired helical filament tau burden. Regions that had cerebral microbleeds or cortical superficial siderosis largely overlapped with those showing increased 18F-AV-1451. Our preliminary study raised the possibility that lobar cerebral microbleeds, and cortical superficial siderosis, which are characteristic markers of vascular amyloid, may be associated with local production of paired helical filament tau.
Keywords: Aged; Aged, 80 and over; Aniline Compounds; Brain; Carbolines; Cerebral Amyloid Angiopathy; Female; Humans; Image Processing, Computer-Assisted; Male; Positron-Emission Tomography; Thiazoles

The 2002 NIMH Provisional Diagnostic Criteria for Depression of Alzheimer's Disease (PDC-dAD): Gauging their Validity over a Decade Later. - Sepehry, Amir A; Lee, Philip E; Hsiung, Ging-Yuek R; Beattie, B Lynn; Feldman, Howard H; Jacova, Claudia (J Alzheimers Dis, 2017)
Presented herein is evidence for criterion, content, and convergent/discriminant validity of the NIMH-Provisional Diagnostic Criteria for depression of Alzheimer's Disease (PDC-dAD) that were formulated to address depression in Alzheimer's disease (AD). Using meta-analytic and systematic review methods, we examined criterion validity evidence in epidemiological and clinical studies comparing the PDC-dAD to Diagnostic and Statistical Manual of Mental Disorders fourth edition (DSM-IV), and International Classification of Disease (ICD 9) depression diagnostic criteria. We estimated prevalence of depression by PDC, DSM, and ICD with an omnibus event rate effect-size. We also examined diagnostic agreement between PDC and DSM. To gauge content validity, we reviewed rates of symptom endorsement for each diagnostic approach. Finally, we examined the PDC's relationship with assessment scales (global cognition, neuropsychiatric, and depression definition) for convergent validity evidence. The aggregate evidence supports the validity of the PDC-dAD. Our findings suggest that depression in AD differs from other depressive disorders including Major Depressive Disorder (MDD) in that dAD is more prevalent, with generally a milder presentation and with unique features not captured by the DSM. Although the PDC are the current standard for diagnosis of depression in AD, we identified the need for their further optimization based on predictive validity evidence.

A 24-Week Multi-Modality Exercise Program Improves Executive Control in Older Adults with a Self-Reported Cognitive Complaint: Evidence from the Antisaccade Task. - Heath, Matthew; Shellington, Erin; Titheridge, Sam; Gill, Dawn P; Petrella, Robert J (J Alzheimers Dis, 2017)
Exercise programs involving aerobic and resistance training (i.e., multiple-modality) have shown promise in improving cognition and executive control in older adults at risk, or experiencing, cognitive decline. It is, however, unclear whether cognitive training within a multiple-modality program elicits an additive benefit to executive/cognitive processes. This is an important question to resolve in order to identify optimal training programs that delay, or ameliorate, executive deficits in persons at risk for further cognitive decline. In the present study, individuals with a self-reported cognitive complaint (SCC) participated in a 24-week multiple-modality (i.e., the M2 group) exercise intervention program. In addition, a separate group of individuals with a SCC completed the same aerobic and resistance training as the M2 group but also completed a cognitive-based stepping task (i.e., multiple-modality, mind-motor intervention: M4 group). Notably, pre- and post-intervention executive control was examined via the antisaccade task (i.e., eye movement mirror-symmetrical to a target). Antisaccades are an ideal tool for the study of individuals with subtle executive deficits because of its hands- and language-free nature and because the task's neural mechanisms are linked to neuropathology in cognitive decline (i.e., prefrontal cortex). Results showed that M2 and M4 group antisaccade reaction times reliably decreased from pre- to post-intervention and the magnitude of the decrease was consistent across groups. Thus, multi-modality exercise training improved executive performance in persons with a SCC independent of mind-motor training. Accordingly, we propose that multiple-modality training provides a sufficient intervention to improve executive control in persons with a SCC.

A 3-Month Aerobic Training Program Improves Brain Energy Metabolism in Mild Alzheimer's Disease: Preliminary Results from a Neuroimaging Study. - Castellano, Christian-Alexandre; Paquet, Nancy; Dionne, Isabelle J; Imbeault, Hélène; Langlois, Francis; Croteau, Etienne; Tremblay, Sébastien; Fortier, Mélanie; Matte, J Jacques; Lacombe, Guy; Fülöp, Tamás; Bocti, Christian; et al. (J Alzheimers Dis, 2017)
BACKGROUND: Aerobic training has some benefits for delaying the onset or progression of Alzheimer's disease (AD). Little is known about the implication of the brain's two main fuels, glucose and ketones (acetoacetate), associated with thesebenefits. OBJECTIVE: To determine whether aerobic exercise training modifies brain energy metabolism in mild AD. METHODS: In this uncontrolled study, ten patients with mild AD participated in a 3-month, individualized, moderate-intensity aerobic training on a treadmill (Walking). Quantitative measurement of brain uptake of glucose (CMRglu) and acetoacetate (CMRacac) using neuroimaging and cognitive testing were done before and after the Walking program. RESULTS: Four men and six women with an average global cognitive score (MMSE) of 26/30 and an average age of 73 y completed the Walking program. Average total distance and treadmill speed were 8 km/week and 4 km/h, respectively. Compared to the Baseline, after Walking, CMRacac was three-fold higher (0.6±0.4 versus 0.2±0.1 μmol/100 g/min; p = 0.01). Plasma acetoacetate concentration and the blood-to-brain acetoacetate influx rate constant were also increased by 2-3-fold (all p≤0.03). CMRglu was unchanged after Walking (28.0±0.1 μmol/100 g/min; p = 0.96). There was a tendency toward improvement in the Stroop-color naming test (-10% completion time, p = 0.06). Performance on the Trail Making A&B tests was also directly related to plasma acetoacetate and CMRacac (all p≤0.01). CONCLUSION: In mild AD, aerobic training improved brain energy metabolism by increasing ketone uptake and utilization while maintaining brain glucose uptake, and could potentially be associated with some cognitive improvement.

A 9-microRNA Signature in Serum Serves as a Noninvasive Biomarker in Early Diagnosis of Alzheimer's Disease. - Guo, Rui; Fan, Gang; Zhang, Jian; Wu, Chunxiao; Du, Yifeng; Ye, Hui; Li, Zhang; Wang, Lili; Zhang, Zhihui; Zhang, Lu; Zhao, Yueran; Lu, Zhiming (J Alzheimers Dis, 2017)
Alzheimer's disease (AD) is the most common type of age-related neurodegenerative disorder; nevertheless, nowadays there are no reliable biomarkers or non-invasive techniques available for its early detection. Recent studies have indicated that the circulating level profiles of microRNAs (miRNAs) have the potential to be used as valuable biomarkers for diagnosis, staging, and progress monitoring of various diseases. Here we report a novel 9-miRNA signature (hsa-miR-26a-5p, hsa-miR-181c-3p, hsa-miR-126-5p, hsa-miR-22-3p, hsa-miR-148b-5p, hsa-miR-106b-3p, hsa-miR-6119-5p, hsa-miR-1246, and hsa-miR-660-5p) that can be utilized as biomarker for detecting AD. We respectively profiled the serum miRNAs from 19 AD patients and 9 healthy control (HC) participants using the Next-Generation Sequencing (NGS). The NGS results were validated by quantitative real-time polymerase chain reaction (qRT-PCR) on a larger cohort of 121 AD and 86 HC cases. All the patients were divided into three groups (mild, moderate, and severe AD) based on the Mini-Mental State Examination (MMSE) and Clinical Dementia Rating (CDR). Our research indicates that abnormal expression of distinct serum miRNAs occurs at different stages of AD. The difference of the area under the receiver operator characteristics curve (AUC) between the AD and the HC is between 70% and 85%. Among the 9 miRNAs, hsa-miR-22-3p has the best sensitivity (81.8%) and specificity (70.9%). The miRNA-panel is more valuable for AD diagnosis. The data suggest that the differentially expressed serum miRNAs could be used as biomarkers to improve the diagnosis of AD, particularly at the early stage, and to classify its clinical stages.

ABCA1 Deficiency Affects Basal Cognitive Deficits and Dendritic Density in Mice. - Fitz, Nicholas F; Carter, Alexis Y; Tapias, Victor; Castranio, Emilie L; Kodali, Ravindra; Lefterov, Iliya; Koldamova, Radosveta (J Alzheimers Dis, 2017)
ATP-binding cassette transporter A1 (ABCA1) mediates cholesterol efflux to lipid-free apolipoproteins and regulates the generation of high density lipoproteins. Previously, we have shown that lack of Abca1 significantly increases amyloid deposition and cognitive deficits in Alzheimer's disease model mice expressing human amyloid-β protein precursor (APP). The goal of this study was to determine if ABCA1 plays a role in memory deficits caused by amyloid-β (Aβ) oligomers and examine neurite architecture of pyramidal hippocampal neurons. Our results confirm previous findings that Abca1 deficiency significantly impairs spatial memory acquisition and retention in the Morris water maze and long-term memory in novel object recognition of APP transgenic mice at a stage of early amyloid pathology. Neither test demonstrated a significant difference between Abca1ko and wild-type (WT) mice. We also examined the effect of intra-hippocampal infused Aβ oligomers on cognitive performance of Abca1ko mice, compared to control infusion of scrambled Aβ peptide. Age-matched WT mice undergoing the same infusions were also used as controls. In this model system, we found a statistically significant difference between WT and Abca1ko mice infused with scrambled Aβ, suggesting that Abca1ko mice are vulnerable to the effect of mild stresses. Moreover, examination of neurite architecture in the hippocampi revealed a significant decrease in neurite length, number of neurite segments, and branches in Abca1ko mice when compared to WT mice. We conclude that mice lacking ABCA1 have basal cognitive deficits that prevent them from coping with additional stressors, which is in part due to impairment of neurite morphology in the hippocampus.

Aberrant Co-localization of Synaptic Proteins Promoted by Alzheimer's Disease Amyloid-β Peptides: Protective Effect of Human Serum Albumin. - Domínguez-Prieto, Marta; Velasco, Ana; Vega, Lourdes; Tabernero, Arantxa; Medina, José M (J Alzheimers Dis, 2017)
Amyloid-β (Aβ), Aβ40, Aβ42, and, recently, Aβ25-35 have been directly implicated in the pathogenesis of Alzheimer's disease. We have studied the effects of Aβ on neuronal death, reactive oxygen species (ROS) production, and synaptic assembling in neurons in primary culture. Aβ25-35, Aβ40, and Aβ42 significantly decreased neuronal viability, although Aβ25-35 showed a higher effect. Aβ25-35 showed a more penetrating ability to reach mitochondria while Aβ40 did not enter the neuronal cytosol and Aβ42 was scarcely internalized. We did not observe a direct correlation between ROS production and cell death because both Aβ40 and Aβ42 decreased neuronal viability but Aβ40 did not change ROS production. Rather, ROS production seems to correlate with the penetrating ability of each Aβ. No significant differences were found between Aβ40 and Aβ42 regarding the extent of the deleterious effects of both peptides on neuronal viability or synaptophysin expression. However, Aβ40 elicited a clear delocalization of PSD-95 and synaptotagmin from prospective synapsis to the neuronal soma, suggesting the occurrence of a crucial effect of Aβ40 on synaptic disassembling. The formation of Aβ40- or Aβ42-serum albumin complexes avoided the effects of these peptides on neuronal viability, synaptophysin expression, and PSD-95/synaptotagmin disarrangement suggesting that sequestration of Aβ by albumin prevents deleterious effects of these peptides. We can conclude that Aβ borne by albumin can be safely transported through body fluids, a fact that may be compulsory for Aβ disposal by peripheral tissues.

Abnormalities of Cerebral Deep Medullary Veins on 7 Tesla MRI in Amnestic Mild Cognitive Impairment and Early Alzheimer's Disease: A Pilot Study. - Bouvy, Willem H; Kuijf, Hugo J; Zwanenburg, Jaco J M; Koek, Huiberdina L; Kappelle, L Jaap; Luijten, Peter R; Ikram, M Kamran; Biessels, Geert Jan (J Alzheimers Dis, 2017)
Cerebral small vessel disease (SVD) contributes to cognitive impairment and dementia. SVD may affect veins, but veins are difficult to detect with 1.5 and 3T MRI. We compared deep medullary veins (DMVs) visualized on 7T-MRI between patients with early Alzheimer's disease (eAD; n = 17) or amnestic MCI (aMCI; n = 12) and controls (n = 40). The number and density of DMVs was similar in patients and controls, but tortuosity was higher in eAD (Cohen's d = 0.7, 95% CI: 0.1-1.2, p = 0.02) and aMCI (Cohen's d = 0.8, 95% CI: 0.2-1.5, p = 0.01), independent of brain atrophy. Venous changes provide a new perspective on vascular involvement in dementia.
Keywords: Aged; Aged, 80 and over; Alzheimer Disease; Analysis of Variance; Brain; Cerebral Small Vessel Diseases; Cognitive Dysfunction; Female; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male

Abnormalities of Cortical Neural Synchronization Mechanisms in Subjects with Mild Cognitive Impairment due to Alzheimer's and Parkinson's Diseases: An EEG Study. - Babiloni, Claudio; Del Percio, Claudio; Lizio, Roberta; Noce, Giuseppe; Cordone, Susanna; Lopez, Susanna; Soricelli, Andrea; Ferri, Raffaele; Pascarelli, Maria Teresa; Nobili, Flavio; Arnaldi, Dario; Famá, Francesco; et al. (J Alzheimers Dis, 2017)
The aim of this retrospective and exploratory study was that the cortical sources of resting state eyes-closed electroencephalographic (rsEEG) rhythms might reveal different abnormalities in cortical neural synchronization in groups of patients with mild cognitive impairment due to Alzheimer's disease (ADMCI) and Parkinson's disease (PDMCI) as compared to healthy subjects. Clinical and rsEEG data of 75 ADMCI, 75 PDMCI, and 75 cognitively normal elderly (Nold) subjects were available in an international archive. Age, gender, and education were carefully matched in the three groups. The Mini-Mental State Evaluation (MMSE) was matched between the ADMCI and PDMCI groups. Individual alpha frequency peak (IAF) was used to determine the delta, theta, alpha1, alpha2, and alpha3 frequency band ranges. Fixed beta1, beta2, and gamma bands were also considered. eLORETA estimated the rsEEG cortical sources. Receiver operating characteristic curve (ROC) classified these sources across individuals. Results showed that compared to the Nold group, the posterior alpha2 and alpha3 source activities were more abnormal in the ADMCI than the PDMCI group, while the parietal delta source activities were more abnormal in the PDMCI than the ADMCI group. The parietal delta and alpha sources correlated with MMSE score and correctly classified the Nold and diseased individuals (area under the ROC = 0.77-0.79). In conclusion, the PDMCI and ADMCI patients showed different features of cortical neural synchronization at delta and alpha frequencies underpinning brain arousal and vigilance in the quiet wakefulness. Future prospective cross-validation studies will have to test these rsEEG markers for clinical applications and drug discovery.

Acceleration of Amyloidosis by Inflammation in the Amyloid-Beta Marmoset Monkey Model of Alzheimer's Disease. - Philippens, Ingrid H; Ormel, Paul R; Baarends, Guus; Johansson, Maja; Remarque, Ed J; Doverskog, Magnus (J Alzheimers Dis, 2017)
BACKGROUND: The immune system is increasingly mentioned as a potential target for Alzheimer's disease (AD) treatment. OBJECTIVE: In the present pilot study, the effect of (neuro)inflammation on amyloidopathy was investigated in the marmoset monkey, which has potential as an AD animal model due to its natural cerebral amyloidosis similar to humans. METHODS: Six adult/aged marmosets (Callithrix jacchus) were intracranial injected with amyloid-beta (Aβ) fibrils at three cortical locations in the right hemisphere. Additionally, in half of the monkeys, lipopolysaccharide (LPS) was co-injected with the Aβ fibrils and injected in the other hemisphere without Aβ fibrils. The other three monkeys received phosphate buffered saline instead of LPS, as a control for the inflammatory state. The effect of inflammation on amyloidopathy was also investigated in an additional monkey that suffered from chronic inflammatory wasting syndrome. Mirror histology sections were analyzed to assess amyloidopathy and immune reaction, and peripheral blood for AD biomarker expression. RESULTS: All LPS-injected monkeys showed an early AD immune blood cell expression profile on CD95 and CD45RA. Two out of three monkeys injected with Aβ and LPS and the additional monkey, suffering from chronic inflammation, developed plaques. None of the controls, injected with Aβ only, developed any plaques. CONCLUSION: This study shows the importance of immune modulation on the susceptibility for amyloidosis, a hallmark of AD, which offers new perspectives for disease modifying approaches in AD.

Accuracy of Clinical Diagnosis of Dementia with Lewy Bodies versus Neuropathology. - Skogseth, Ragnhild; Hortobágyi, Tibor; Soennesyn, Hogne; Chwiszczuk, Luiza; Ffytche, Dominic; Rongve, Arvid; Ballard, Clive; Aarsland, Dag (J Alzheimers Dis, 2017)
BACKGROUND: The first consensus criteria for dementia with Lewy bodies (DLB) published in 1996 were revised in 2005, partly because the original clinical criteria had suboptimal sensitivity. Few studies have assessed the accuracy of the 2005 criteria applied prospectively in newly diagnosed patients who have been followed longitudinally. OBJECTIVE: To explore the correlation between clinical and pathological diagnoses in patients with DLB and Parkinson's disease with dementia (PDD). METHODS: From a prospective referral cohort study with enriched recruitment of patients with DLB and PDD, we included the first 56 patients coming to autopsy. Patients had mild dementia at inclusion and were followed annually until death with standardized clinical assessments. Pathological assessment was performed blind to clinical information according to standardized protocols and consensus criteria for DLB. RESULTS: 20 patients received a pathological diagnosis of Lewy body disease; the corresponding clinical diagnoses were probable DLB (n = 11), PDD (n = 5), probable (n = 2) or possible (n = 2) Alzheimer's disease (AD). Of 14 patients with a clinical diagnosis of probable DLB, 11 had DLB/PDD and 3 had AD at pathology. One patient with clinically possible DLB fulfilled criteria for pathological AD. Sensitivity, specificity, positive predictive value, and negative predictive values for probable DLB were 73%, 93%, 79%, and 90%. CONCLUSION: Our findings suggest that the international clinical consensus criteria for DLB perform reasonably well. However, false positive and false negative diagnoses still occur, indicating that the criteria need to be improved, that biomarkers may be needed, and that neuropathological feedback is vital to improve accuracy.

Acidity and Acid-Sensing Ion Channels in the Normal and Alzheimer's Disease Brain. - Gonzales, Eric B; Sumien, Nathalie (J Alzheimers Dis, 2017)
Alzheimer's disease prevalence has reached epidemic proportion with very few treatment options, which are associated with a multitude of side effects. A potential avenue of research for new therapies are protons, and their associated receptor: acid-sensing ion channels (ASIC). Protons are often overlooked neurotransmitters, and proton-gated currents have been identified in the brain. Furthermore, ASICs have been determined to be crucial for proper brain function. While there is more work to be done, this review is intended to highlight protons as neurotransmitters and their role along with the role of ASICs within physiological functioning of the brain. We will also cover the pathophysiological associations between ASICs and modulators of ASICs. Finally, this review will sum up how the studies of protons, ASICs and their modulators may generate new therapeutic molecules for Alzheimer's disease and other neurodegenerative diseases.

Activation of Macrophages and Microglia by Interferon-γ and Lipopolysaccharide Increases Methylglyoxal Production: A New Mechanism in the Development of Vascular Complications and Cognitive Decline in Type 2 Diabetes Mellitus? - Dhananjayan, Karthik; Gunawardena, Dhanushka; Hearn, Nerissa; Sonntag, Tanja; Moran, Chris; Gyengesi, Erika; Srikanth, Velandai; Münch, Gerald (J Alzheimers Dis, 2017)
Methylglyoxal (MGO), a dicarbonyl compound derived from glucose, is elevated in diabetes mellitus and contributes to vascular complications by crosslinking collagen and increasing arterial stiffness. It is known that MGO contributes to inflammation as it forms advanced glycation end products (AGEs), which activate macrophages via the receptor RAGE. The aim of study was to investigate whether inflammatory activation can increase MGO levels, thereby completing a vicious cycle. In order to validate this, macrophage (RAW264.7, J774A.1) and microglial (N11) cells were stimulated with IFN-γ and LPS (5 + 5 and 10 + 10 IFN-γ U/ml or μg/ml LPS), and extracellular MGO concentration was determined after derivatization with 5,6-Diamino-2,4-dihydroxypyrimidine sulfate by HPLC. MGO levels in activated macrophage cells (RAW264.7) peaked at 48 h, increasing 2.86-fold (3.14±0.4 μM) at 5 U/ml IFN-γ+5 μg/ml LPS, and 4.74-fold (5.46±0.30 μM) at 10 U/ml IFN-γ+10 μg/ml LPS compared to the non-activated controls (1.15±0.02 μM). The other two cell lines, J774A.1 macrophages and N11 microglia, showed a similar response. We suggest that inflammation increases MGO production, possibly exacerbating arterial stiffness, cardiovascular complications, and diabetes-related cognitive decline.

Adherence to Clinical Practice Guidelines during Dementia Work-Up in a Real-World Setting: A Study from the Registry of Dementias of Girona. - Turró-Garriga, Oriol; Calvó-Perxas, Laia; Vilalta-Franch, Joan; Hernández-Ferrándiz, Marta; Flaqué, Margarita; Linares, Marta; Cullell, Marta; Gich, Jordi; Casas, Isabel; Perkal, Héctor; Garre-Olmo, Josep (J Alzheimers Dis, 2017)
BACKGROUND: There are several position statements and clinical practice guidelines (CPG) for diagnosing dementia. OBJECTIVE: Our aims were to evaluate the adherence to CPG among specialists in the 7 memory clinics included in the Registry of Dementias of Girona (ReDeGi), and to compare the results between 2007-2011 and 2012-2015. We also determined the time and number of visits required to achieve a diagnosis, the supplementary tests ordered, and the drugs prescribed according to dementia subtypes. METHODS: Medical charts of a stratified random sample of 475 ReDeGi cases were reviewed. Basic dementia work-up was evaluated using as a reference evidence-based CPG. An Index of Adherence (AI) was calculated using the following items in the medical chart: cognitive symptomatology; functional disability evaluation; physical examination; neurological examination; psychiatric examination; brief cognitive examination; activities of daily living performance examination; blood test; structural neuroimaging (CT-scan or MRI). RESULTS: The mean AI to CPG among specialists was of 8.2 points, and it improved from 7.9 points in 2007-2011 to 8.5 points in 2012-2015 (Cohen's d = 0.46). A lower adherence was detected in the most severe cases. A dementia diagnosis required 3.5 visits, regardless of the subtype of dementia, although milder cases required more time, more visits, and more supplementary tests than severe cases. CONCLUSION: The adherence to CPG in the catchment area of the ReDeGi is high, and an epidemiological surveillance system such as the ReDeGi may help in improving it. Dementia guidelines should establish procedures adapted to clinical practice, with simplified recommendations for most severe cases.

Adult-Onset Epilepsy in Presymptomatic Alzheimer's Disease: A Retrospective Study. - DiFrancesco, Jacopo C; Tremolizzo, Lucio; Polonia, Valeria; Giussani, Giorgia; Bianchi, Elisa; Franchi, Carlotta; Nobili, Alessandro; Appollonio, Ildebrando; Beghi, Ettore; Ferrarese, Carlo (J Alzheimers Dis, 2017)
BACKGROUND: The prevalence of epilepsy with onset in adulthood increases with age, mainly due to the accumulation of brain damage. However, a significant proportion of patients experience seizures of unknown cause. Alzheimer's disease (AD) is associated with an increased risk of seizures. Seizure activity is interpreted as a secondary event related to hyperexcitability caused by amyloid-β aggregation. OBJECTIVE: Since neurodegenerative processes begin several years before clinical symptoms, epilepsy could be more frequent in the presymptomatic stages of dementia. METHODS: We retrospectively reviewed the prevalence of epilepsy of unknown origin with adult onset before cognitive decline in a large cohort of AD patients (EPS-AD) recruited based on clinical and neuropsychological data. Data of patients with epilepsy followed by AD were compared with two control groups: patients with AD without seizures (no EPS-AD) and a large reference population (RP). RESULTS: In AD patients, the prevalence of epilepsy of unknown origin, with onset in the adulthood before cognitive decline is 17.1 times higher compared with the RP (95% CI: 10.3-28.3). In EPS-AD, seizures begin on average 4.6 years (median 2.0) before the onset of cognitive symptoms and cognitive decline starts 3.6 years earlier compared with noEPS-AD. CONCLUSIONS: Neurodegenerative processes of dementia could play a key role in the pathogenesis of epilepsy in a subgroup of individuals intended to develop cognitive decline. Adult-onset epilepsy of undefined cause could thus represent a risk factor for the ongoing neurodegenerative damage, even preceding by years the onset of clinical symptoms of dementia.

Aerosol Delivery of Curcumin Reduced Amyloid-β Deposition and Improved Cognitive Performance in a Transgenic Model of Alzheimer's Disease. - McClure, Richard; Ong, Henry; Janve, Vaibhab; Barton, Shawn; Zhu, Meiying; Li, Bo; Dawes, Mary; Jerome, W Gray; Anderson, Adam; Massion, Pierre; Gore, John C; Pham, Wellington (J Alzheimers Dis, 2017)
We report a novel approach for the delivery of curcumin to the brain via inhalation of the aerosol for the potential treatment of Alzheimer's disease. The percentage of plaque fraction in the subiculum and hippocampus reduced significantly when young 5XFAD mice were treated with inhalable curcumin over an extended period of time compared to age-matched nontreated counterparts. Further, treated animals demonstrated remarkably improved overall cognitive function, no registered systemic or pulmonary toxicity associated with inhalable curcumin observed during the course of this work.

Age and Graphomotor Decision Making Assessed with the Digital Clock Drawing Test: The Framingham Heart Study. - Piers, Ryan J; Devlin, Kathryn N; Ning, Boting; Liu, Yulin; Wasserman, Ben; Massaro, Joseph M; Lamar, Melissa; Price, Catherine C; Swenson, Rod; Davis, Randall; Penney, Dana L; Au, Rhoda; et al. (J Alzheimers Dis, 2017)
BACKGROUND: Digital Clock Drawing Test (dCDT) technology enables the examination of detailed neurocognitive behavior as behavior unfolds in real time; a capability that cannot be obtained using a traditional pen and paper testing format. OBJECTIVE: Parameters obtained from the dCDT were used to investigate neurocognitive constructs related to higher-order neurocognitive decision making and information processing speed. The current research sought to determine the effect of age as related to combined motor and non-motor components of drawing, and higher-order decision making latencies. METHODS: A large group of stroke- and dementia- free Framingham Heart Study participants were administered the dCDT to command and copy with hands set for "10 after 11". Six age groups (age range 28-98) were constructed. RESULTS: Differences between age groups were found for total time to completion, total pen stroke count, and higher-order decision making latencies in both command and copy test conditions. CONCLUSION: Longer age-related decision making latencies may reflect a greater need for working memory and increased self-monitoring in older subjects. These latency measures have potential to serve as neurocognitive biomarkers of Alzheimer's disease and other insidious neurodegenerative disorders.

Alcohol Intake and Cognitively Healthy Longevity in Community-Dwelling Adults: The Rancho Bernardo Study. - Richard, Erin L; Kritz-Silverstein, Donna; Laughlin, Gail A; Fung, Teresa T; Barrett-Connor, Elizabeth; McEvoy, Linda K (J Alzheimers Dis, 2017)
To better understand the association of alcohol intake with cognitively healthy longevity (CHL), we explored the association between amount and frequency of alcohol intake and CHL among 1,344 older community-dwelling adults. Alcohol intake was assessed by questionnaire in 1984-1987. Cognitive function was assessed in approximate four-year intervals between 1988 and 2009. Multinomial logistic regression, adjusting for multiple lifestyle and health factors, was used to examine the association between alcohol consumption and CHL (living to age 85 without cognitive impairment), survival to age 85 with cognitive impairment (MMSE score >1.5 standard deviations below expectation for age, sex, and education), or death before age 85. Most participants (88%) reported some current alcohol intake; 49% reported a moderate amount of alcohol intake, and 48% reported drinking near-daily. Relative to nondrinkers, moderate and heavy drinkers (up to 3 drinks/day for women and for men 65 years and older, up to 4 drinks/day for men under 65 years) had significantly higher adjusted odds of survival to age 85 without cognitive impairment (p's < 0.05). Near-daily drinkers had 2-3 fold higher adjusted odds of CHL versus living to at least age 85 with cognitive impairment (odds ratio (OR) = 2.06; 95% confidence interval (CI): 1.21, 3.49) or death before 85 (OR = 3.24; 95% CI: 1.92, 5.46). Although excessive drinking has negative health consequences, these results suggest that regular, moderate drinking may play a role in cognitively healthy longevity.

Algoplus® Scale in Older Patients with Dementia: A Reliable Real-World Pain Assessment Tool. - Monacelli, Fiammetta; Signori, Alessio; Roffredo, Laura; Pace, Katiuscia; Nencioni, Alessio; Pickering, Gisele; Nicolas, Macian; Odetti, Patrizio (J Alzheimers Dis, 2017)
Pain is still a neglected clinical issue in elderly people with dementia and/or communicative disorders, with an unacceptable higher rate of under diagnosis and under treatment. Cognitive deficit and emotional and psychological disturbances entangle pain symptoms, affecting patient self-report. So far, observational pain tools do not have fully adequate clinimetric properties and quality requirements for easy-to-use daily rating. Older patients with dementia represent a clinical challenge. The assessment of pain is important for improving clinical outcomes, such as functional status, frailty trajectories, comorbidity, and quality of life. The PAINAID scale appears to be the most accurate pain tool in people with dementia along with the Algoplus® scale, a recently developed tool to rapidly assess acute pain in hospitals settings. The present study aimed to assess the clinimetric properties of the Algoplus®, as compared to PAINAID, for detecting acute pain in a real-world cohort of hospitalized older patients with dementia.

The Alteration of ZiBuPiYin Recipe on Proteomic Profiling of Forebrain Postsynaptic Density of db/db Mice with Diabetes-Associated Cognitive Decline. - Chen, Jing; Zhan, Libin; Lu, Xiaoguang; Xiao, Chi; Sun, Nijing (J Alzheimers Dis, 2017)
Diabetes-associated cognitive decline (DACD) is a brain injury induced by diabetes mellitus, with cognitive impairment as the major symptom. Growing evidence has revealed that DACD is correlated with disruptions in synapses involved in cognition. Within synapses, more specifically in areas of postsynaptic density (PSD), there is a high concentration of proteins that receive and transduce synaptic information. In the present study, to identify the differentially expressed PSD proteins among DACD mice, ZiBuPiYin recipe (ZBPYR)-treated DACD mice and control mice, we applied isobaric tags for relative and absolute quantitation (iTRAQ) with LC-MS/MS technology, by which three biological replicates and three technical replicates were examined. A total of 24 and 23 differentially expressed proteins were observed in control versus DACD mice and in DACD versus ZBPYR-treated DACD mice, respectively. Notably, we found 'Protein processing in endoplasmic reticulum' and 'PI3K-Akt signaling pathway' might be impaired in DACD pathogenesis, while Growth factor receptor-bound protein 2 might be a crucial protein as a molecular target of the neuroprotective effects of ZBPYR. To our knowledge, this is the first study to provide a reference proteome map for DACD and ZBPYR-treated DACD mouse forebrain PSD to aid understanding the underlying mechanisms of DACD and ZBPYR.

Alterations in the Balance of Amyloid-β Protein Precursor Species in the Cerebrospinal Fluid of Alzheimer's Disease Patients. - Lopez-Font, Inmaculada; Boix, Claudia P; Zetterberg, Henrik; Blennow, Kaj; Sáez-Valero, Javier (J Alzheimers Dis, 2017)
We recently demonstrated that soluble forms of the amyloid-β protein precursor (sAβPP) assemble into multimeric complexes in cerebrospinal fluid (CSF), which contributes to the underestimation of specific sAβPP species when assessed by ELISA. To circumvent this issue, we analyzed by SDS-PAGE large fragments of sAβPP and their variants in the CSF from Alzheimer's disease (AD; n = 20) and control (n = 20) subjects, probing with specific antibodies against particular domains. Similar levels of sAβPPα and sAβPPβ protein were found in CSF samples from AD and controls, yet there appeared to be a shift in the balance of the soluble full-length AβPP (sAβPPf) species in AD samples, with a decrease in the proportion of the lower (∼100 kDa) band relative to the upper (∼120 kDa) band. Similar differences were observed in the contribution of the major KPI-immunoreactive AβPP species. CSF samples also displayed differences in the correlations of AβPP species with classical AD biomarkers, particularly with respect to the Aβ42 peptide. The differences reveal alterations that probably reflect pathophysiological changes in the brain.

Alterations in the Peripheral Immune System in Dementia. - Busse, Mandy; Michler, Enrico; von Hoff, Franz; Dobrowolny, Henrik; Hartig, Roland; Frodl, Thomas; Busse, Stefan (J Alzheimers Dis, 2017)
Alterations in the immune response that result in inflammation might play a role in the pathology of dementias. In order to analyze changes of the peripheral immune system associated with different types of dementias, we determined several innate and adaptive cell populations in whole blood using flow cytometry. We included patients with Alzheimer's disease (AD; n = 60), vascular dementia (VaD; n = 20), and frontotemporal dementia (FTD; n = 12) at the time point of diagnosis and 24 age-matched neuropsychiatric healthy persons. Monocytes and NK cells were diminished in VaD, but not in AD and FTD. B cell and T cell numbers were decreased in all investigated forms of dementia. Changes in the contribution of naïve/memory T cells were only present in AD. Correlation and regression analyses revealed associations between altered immune cell populations and Q Albumin as marker for the integrity of the blood-cerebrospinal fluid-barrier, Mini-Mental State Examination values, and age. The peripheral immune system is altered in AD, VaD, and FTD. However, each disorder presents unique changes in the investigated cell types indicating different mechanisms underlying the pathology.

Alterations of Clock Gene RNA Expression in Brain Regions of a Triple Transgenic Model of Alzheimer's Disease. - Bellanti, Francesco; Iannelli, Giuseppina; Blonda, Maria; Tamborra, Rosanna; Villani, Rosanna; Romano, Adele; Calcagnini, Silvio; Mazzoccoli, Gianluigi; Vinciguerra, Manlio; Gaetani, Silvana; Giudetti, Anna Maria; Vendemiale, Gianluigi; et al. (J Alzheimers Dis, 2017)
A disruption to circadian rhythmicity and the sleep/wake cycle constitutes a major feature of Alzheimer's disease (AD). The maintenance of circadian rhythmicity is regulated by endogenous clock genes and a number of external Zeitgebers, including light. This study investigated the light induced changes in the expression of clock genes in a triple transgenic model of AD (3×Tg-AD) and their wild type littermates (Non-Tg). Changes in gene expression were evaluated in four brain areas¾suprachiasmatic nucleus (SCN), hippocampus, frontal cortex and brainstem¾of 6- and 18-month-old Non-Tg and 3×Tg-AD mice after 12 h exposure to light or darkness. Light exposure exerted significant effects on clock gene expression in the SCN, the site of the major circadian pacemaker. These patterns of expression were disrupted in 3×Tg-AD and in 18-month-old compared with 6-month-old Non-Tg mice. In other brain areas, age rather than genotype affected gene expression; the effect of genotype was observed on hippocampal Sirt1 expression, while it modified the expression of genes regulating the negative feedback loop as well as Rorα, Csnk1ɛ and Sirt1 in the brainstem. In conclusion, during the early development of AD, there is a disruption to the normal expression of genes regulating circadian function after exposure to light, particularly in the SCN but also in extra-hypothalamic brain areas supporting circadian regulation, suggesting a severe impairment of functioning of the clock gene pathway. Even though this study did not demonstrate a direct association between these alterations in clock gene expression among brain areas with the cognitive impairments and chrono-disruption that characterize the early onset of AD, our novel results encourage further investigation aimed at testing this hypothesis.

Altered Gut Microbiome Composition and Tryptic Activity of the 5xFAD Alzheimer's Mouse Model. - Brandscheid, Carolin; Schuck, Florian; Reinhardt, Sven; Schäfer, Karl-Herbert; Pietrzik, Claus U; Grimm, Marcus; Hartmann, Tobias; Schwiertz, Andreas; Endres, Kristina (J Alzheimers Dis, 2017)
The regulation of physiological gut functions such as peristalsis or secretion of digestive enzymes by the central nervous system via the Nervus vagus is well known. Recent investigations highlight that pathological conditions of neurological or psychiatric disorders might directly interfere with the autonomous neuronal network of the gut - the enteric nervous system, or even derive from there. By using a murine Alzheimer's disease model, we investigated a potential influence of disease-associated changes on gastrointestinal properties. 5xFAD mice at three different ages were compared to wild type littermates in regard to metabolic parameters and enzymes of the gut by fluorimetric enzyme assay and western blotting. Overexpression of human amyloid-β protein precursor (AβPP) within the gut was assessed by qPCR and IHC; fecal microbiome analysis was conducted by 16SrRNA quantitation of selected phyla and species. While general composition of fecal samples, locomotion, and food consumption of male 5xFAD animals were not changed, we observed a reduced body weight occurring at early pathological stages. Human AβPP was not only expressed within the brain of these mice but also in gut tissue. Analysis of fecal proteins revealed a reduced trypsin amount in the 5xFAD model mice as compared to the wild type. In addition, we observed changes in fecal microbiota composition along with age. We therefore suggest that the presence of the mutated transgenes (AβPP and PS1), which are per se the basis for the genetic form of Alzheimer's disease in humans, directly interferes with gut function as shown here for the disease model mice.

Altered Gut Microbiota in a Mouse Model of Alzheimer's Disease. - Zhang, Ling; Wang, Ying; Xiayu, Xia; Shi, Changhua; Chen, Wei; Song, Nan; Fu, Xinjing; Zhou, Rui; Xu, Yan-Feng; Huang, Lan; Zhu, Hua; Han, Yunlin; et al. (J Alzheimers Dis, 2017)
The topic of gut microbiota is currently attracting considerable interest as a potential factor in Alzheimer's disease (AD). However, the extent and time course of alterations in the gut microbiota, and their effects on AD pathology remain uncertain. Herein, we compared the fecal microbiomes and fecal short chain fatty acid composition (SCFAs) between wild-type and AD model mice at different ages under strictly controlled specific pathogen free conditions, and also conducted microscopic investigations of intestinal structures. Our results showed that the microbiota composition and diversity were perturbed and the level of SCFAs was reduced in AD mice, predicting alterations in more than 30 metabolic pathways, which may be associated with amyloid deposition and ultrastructural abnormalities in AD mouse intestine. These findings indicate that AD pathology might not only affect brain function directly, but also exacerbate cognitive deficits through reducing the level of SCFAs via alterations of gut microbiota induced by intestinal amyloid deposition. Our data may support a role of gut microbiota, and suggest a novel route for therapeutic intervention in AD.

Altered Sphingolipid Balance in Capillary Cerebral Amyloid Angiopathy. - de Wit, Nienke M; Snkhchyan, Hripsime; den Hoedt, Sandra; Wattimena, Darcos; de Vos, Rob; Mulder, Monique T; Walter, Jochen; Martinez-Martinez, Pilar; Hoozemans, Jeroen J; Rozemuller, Annemieke J; De Vries, Helga E (J Alzheimers Dis, 2017)
BACKGROUND: The majority of patients with Alzheimer's disease (AD) exhibit amyloid-β (Aβ) deposits at the brain vasculature, a process referred to as cerebral amyloid angiopathy (CAA). In over 51% of AD cases, Aβ also accumulates in cortical capillaries, which is termed capillary CAA (capCAA). It has been postulated that the presence of capCAA in AD is a specific subtype of AD, although underlying mechanisms are not yet fully understood. Sphingolipids (SLs) are implicated in neurodegenerative disorders, including AD. However, to date it remains unknown whether alterations in the SL pathway are involved in capCAA pathogenesis and if these differ from AD. OBJECTIVE: To determine whether AD cases with capCAA have an altered SL profile compared to AD cases without capCAA. METHODS: Immunohistochemistry was performed to assess the expression and localization of ceramide, acid sphingomyelinase (ASM), and sphingosine-1-phosphate receptors (S1P1, S1P3). In addition, we determined the concentrations of S1P as well as different chain-lengths of ceramides using HPLC-MS/MS. RESULTS: Immunohistochemical analysis revealed an altered expression of ceramide, ASM, and S1P receptors by reactive astrocytes and microglial cells specifically associated with capCAA. Moreover, a shift in the balance of ceramides with different chain-lengths and S1P content is observed in capCAA. CONCLUSION: Here we provide evidence of a deregulated SL balance in capCAA. The increased levels of ASM and ceramide in activated glia cells suggest that the SL pathway is involved in the neuroinflammatory response in capCAA pathogenesis. Future research is needed to elucidate the role of S1P in capCAA.

Alzheimer's Disease as the Product of a Progressive Energy Deficiency Syndrome in the Central Nervous System: The Neuroenergetic Hypothesis. - Blonz, Edward R (J Alzheimers Dis, 2017)
The decreased availability of metabolizable energy resources in the central nervous system is hypothesized to be a key factor in the pathogenesis of Alzheimer's disease. More specifically, the age-related decline in the ability of glucose to cross the blood-brain barrier creates a metabolic stress that shifts the normal, benign processing of amyloid-β protein precursor toward pathways associated with the production of amyloid-β plaques and tau-containing neurofibrillary tangles that are characteristic of the disease. The neuroenergetic hypothesis provides insight into the etiology of Alzheimer's disease and illuminates new approaches for diagnosis, monitoring, and treatment.

Alzheimer's Disease Biomarkers and Future Decline in Cognitive Normal Older Adults. - Dumurgier, Julien; Hanseeuw, Bernard J; Hatling, Frances B; Judge, Kelly A; Schultz, Aaron P; Chhatwal, Jasmeer P; Blacker, Deborah; Sperling, Reisa A; Johnson, Keith A; Hyman, Bradley T; Gómez-Isla, Teresa (J Alzheimers Dis, 2017)
BACKGROUND: Identifying older adults at risk of cognitive decline represents a challenge as Alzheimer's disease (AD) modifying therapies move toward preclinical stages. OBJECTIVE: To investigate the relationship between AD biomarkers and subsequent change in cognition in a cohort of cognitively intact older adults. METHODS: 84 cognitively normal subjects (mean age 72.0 years, 59% women) were recruited through the Massachusetts Alzheimer's Disease Research Center and the Harvard Aging Brain Study and followed over 3 years. Measurements of amyloid-β 1-42 (Aβ42), total Tau (t-Tau), and Tau phosphorylated at threonine 181 (p-Tau181) in the cerebrospinal fluid (CSF) at study entry were available in all cases. Baseline brain MRI, FDG-PET, and PiB-PET data were available in the majority of participants. Relationship between baseline AD biomarkers and longitudinal change in cognition was assessed using Cox proportional hazard regression and linear mixed models. RESULTS: 14% participants increased their global Clinical Dementia Rating (CDR) score from 0 to 0.5 during follow-up. A CDR score increase was associated with higher baseline CSF t-Tau and p-Tau181, higher global cortical PiB retention, and lower hippocampal volume. The combination of high CSF t-Tau and low Aβ42 or low hippocampal volume was more strongly related to cognitive outcome than each single biomarker. Higher CSF t-Tau was the only biomarker associated with subsequent decline in MMSE score. CONCLUSIONS: Baseline CSF t-Tau and p-Tau181, in vivo amyloid load, and hippocampal volume were all independently associated with future decline in cognition. The discriminatory ability of these biomarkers to predict risk of cognitive decline, however, was only modest.

Alzheimer's Disease Biomarkers Interactively Influence Physical Activity, Mobility, and Cognition Associations in a Non-Demented Aging Population. - Thibeau, Sherilyn; McFall, G Peggy; Camicioli, Richard; Dixon, Roger A (J Alzheimers Dis, 2017)
BACKGROUND: Alzheimer's disease (AD) risk-reduction strategies (e.g., increasing physical activity, improving mobility) have garnered increasing attention in the literature. However, the effect of such modifiable factors on the preclinical trajectories of brain and cognitive health may be moderated by non-modifiable biomarkers associated with AD. OBJECTIVE: In a longitudinal sample of non-demented older adults, we examine the independent predictors everyday physical activity (EPA) and mobility on executive function (EF) performance and change. Next, we test whether these predictions are modified by interactions between age and AD genetic risk. METHODS: This accelerated longitudinal design included adults (n = 532, M age = 70.4, age range 53-95) from the Victoria Longitudinal Study. We tested the independent effects of EPA and Mobility (i.e., gait, balance), moderation by Apolipoprotein E (i.e., APOEɛ4+, ɛ4-) and age (young-old, middle-old, old-old), and interactions between APOE and age on performance and 9-year change in an EF latent variable. RESULTS: First, higher levels of both EPA and Mobility were associated with better EF performance and less decline. Second, the interaction between age and APOE showed that low EPA and older age was associated with poorer EF performance and steeper EF decline for APOEɛ4 + carriers, and low mobility was associated with poorer EF performance and steeper EF decline for APOEɛ4 + carriers than the non-risk carriers. CONCLUSION: In non-demented older adults, age moderated the effects of both EPA and Mobility on EF performance and change. However, this moderation occurs differentially across APOE4 status.

Alzheimer's Disease: Characterization of the Brain Sites of the Initial Tau Cytoskeletal Pathology Will Improve the Success of Novel Immunological Anti-Tau Treatment Approaches. - Rüb, Udo; Stratmann, Katharina; Heinsen, Helmut; Seidel, Kay; Bouzrou, Mohamed; Korf, Horst-Werner (J Alzheimers Dis, 2017)
Alzheimer's disease (AD) represents the most frequent neurodegenerative disease of the human brain worldwide. Currently practiced treatment strategies for AD only include some less effective symptomatic therapeutic interventions, which unable to counteract the disease course of AD. New therapeutic attempts aimed to prevent, reduce, or remove the extracellular depositions of the amyloid-β protein did not elicit beneficial effects on cognitive deficits or functional decline of AD. In view of the failure of these amyloid-β-based therapeutic trials and the close correlation between the brain pathology of the cytoskeletal tau protein and clinical AD symptoms, therapeutic attention has since shifted to the tau cytoskeletal protein as a novel drug target. The abnormal hyperphosphorylation and intraneuronal aggregation of this protein are early events in the evolution of the AD-related neurofibrillary pathology, and the brain spread of the AD-related tau aggregation pathology may possibly follow a corruptive protein templating and seeding-like mechanism according to the prion hypothesis. Accordingly, immunotherapeutic targeting of the tau aggregation pathology during the very early pre-tangle phase is currently considered to represent an effective and promising therapeutic approach for AD. Recent studies have shown that the initial immunoreactive tau aggregation pathology already prevails in several subcortical regions in the absence of any cytoskeletal changes in the cerebral cortex. Thus, it may be hypothesized that the subcortical brain regions represent the "port of entry" for the pathogenetic agent from which the disease ascends anterogradely as an "interconnectivity pathology".
Keywords: Alzheimer Disease; Amyloid beta-Peptides; Animals; Brain; Humans; Immunotherapy; tau Proteins

Alzheimer's Disease Diagnosis Relies on a Twofold Clinical-Biological Algorithm: Three Memory Clinic Case Reports. - Levy Nogueira, Marcel; Samri, Dalila; Epelbaum, Stéphane; Lista, Simone; Suppa, Per; Spies, Lothar; Hampel, Harald; Dubois, Bruno; Teichmann, Marc (J Alzheimers Dis, 2017)
The International Working Group recently provided revised criteria of Alzheimer's disease (AD) proposing that the diagnosis of typical amnesic AD should be established by a clinical-biological signature, defined by the phenotype of an "amnesic syndrome of the hippocampal type" (ASHT) combined with positive in vivo evidence of AD pathophysiology in the cerebrospinal fluid (CSF) or on amyloid PET imaging. The application and clinical value of this refined diagnostic algorithm, initially intended for research purposes, is explored in three memory clinic cases presenting with different cognitive profiles including an ASHT, hippocampal atrophy, and CSF AD-biomarker data. The case reports highlight that the isolated occurrence of one of the two proposed AD criteria, ASHT or positive pathophysiological markers, does not provide a reliable diagnosis of typical AD. It is proposed that the twofold diagnostic IWG algorithm can be applied and operationalized in memory clinic settings to improve the diagnostic accuracy of typical amnesic AD in clinical practice.