%0 Journal Article %J J Alzheimers Dis %D 2018 %T The Emergence of a New Conceptual Framework for Alzheimer's Disease. %A Dubois, Bruno %X

The New Criteria for the diagnosis of Alzheimer's disease (AD), published by a group of experts in 2007, have resulted in a revolution in the comprehension of the disease. Before 2007, the diagnosis of AD dementia was done through a process of exclusion: it was considered in the case of patients with a dementia syndrome without identified etiologies. This traditional algorithm had three major limitations that penalize the disease: 1) a low accuracy of the performance which may share responsibility for negative results in clinical trials; 2) a late identification of the patients only when they reach the threshold of dementia which may delay the activation of optimal care; and last but not least, 3) an absence of clear recognition of AD as a disease because of the lack of specific arguments for its identification. Since 2007, the disease has gained a clear definition based on positive evidence: a specific clinical phenotype (the amnestic syndrome of the hippocampal type) and the presence of biomarkers, considered as a biological signature of the disease. Thanks to these positive arguments, AD is a clinically and biologically well-delineated disease, no longer defined as "probable". It is now possible to certify that a given patient has or does not have the disease. Like diabetes, cancer, hyperthyroidism or any other disorder, AD has now a clear definition with well-defined borders. The disease has entered the world of medicine with identified diseases with a biological fingerprint. This is the story of this adventure that we will present now.

%B J Alzheimers Dis %V 62 %P 1059-1066 %8 2018 %G eng %N 3 %1 http://www.ncbi.nlm.nih.gov/pubmed/29036825?dopt=Abstract %R 10.3233/JAD-170536 %0 Journal Article %J J Alzheimers Dis %D 2018 %T Influence of Lewy Pathology on Alzheimer's Disease Phenotype: A Retrospective Clinico-Pathological Study. %A Roudil, Jennifer %A Deramecourt, Vincent %A Dufournet, Boris %A Dubois, Bruno %A Ceccaldi, Mathieu %A Duyckaerts, Charles %A Pasquier, Florence %A Lebouvier, Thibaud %X

BACKGROUND: Studies have shown the frequent coexistence of Lewy pathology (LP) in Alzheimer's Disease (AD).

OBJECTIVE: The aim of this study was to determine the influence of LP on the clinical and cognitive phenotype in a cohort of patients with a neuropathological diagnosis of AD.

METHODS: We reviewed neuropathologically proven AD cases, reaching Braak stages V and VI in the brain banks of Lille and Paris between 1993 and 2016, and classified them according to LP extension (amygdala, brainstem, limbic, or neocortical). We then searched patient files for all available clinical and neuropsychiatric features and neuropsychological data.

RESULTS: Thirty-three subjects were selected for this study, among which 16 were devoid of LP and 17 presented AD with concomitant LP. The latter were stratified into two subgroups according to LP distribution: 7 were AD with amygdala LP and 10 were AD with 'classical' (brainstem, limbic or neocortical) LP. When analyzing the incidence of each clinical feature at any point during the disease course, we found no significant difference in symptom frequency between the three groups. However, fluctuations appeared significantly earlier in patients with classical LP (2±3.5 years) than in patients without LP (7±1.7 years) or with amygdala LP (8±2.8 years; p < 0.01). There was no significant difference in cognitive profiles.

CONCLUSION: Our findings suggest that the influence of LP on the clinical phenotype of AD is subtle. Core features of dementia with Lewy bodies do not allow clinical diagnosis of a concomitant LP on a patient-to-patient basis.

%B J Alzheimers Dis %V 63 %P 1317-1323 %8 2018 %G eng %N 4 %1 http://www.ncbi.nlm.nih.gov/pubmed/29758938?dopt=Abstract %R 10.3233/JAD-170914 %0 Journal Article %J J Alzheimers Dis %D 2018 %T Parietal Involvement in the Semantic Variant of Primary Progressive Aphasia with Alzheimer's Disease Cerebrospinal Fluid Profile. %A Bera, Géraldine %A Migliaccio, Raffaella %A Michelin, Thibaut %A Lamari, Foudil %A Ferrieux, Sophie %A Nogues, Marie %A Bertin, Hugo %A Habert, Marie Odile %A Dubois, Bruno %A Teichmann, Marc %A Kas, Aurélie %X

Semantic variant of primary progressive aphasia (svPPA) is typically associated with non-Alzheimer's disease (AD) pathology. However, some anatomopathological studies have found AD lesions in those patients. We compared brain perfusion SPECT of 18 svPPA patients with cerebrospinal fluid (CSF) biomarkers indicative of non-AD pathology (svPPA-nonAD) and three svPPA patients with CSF biomarkers indicative of underlying AD (svPPA-AD). All svPPA patients had severe left temporopolar hypoperfusion. SvPPA-nonAD had additional anterior cingulate and mediofrontal hypoperfusion, whereas svPPA-AD had greater left parietal and posterior cingulate involvement. Parietal damage in svPPA constitutes a biomarker for underlying Alzheimer pathology thus refining the classification of this PPA variant.

%B J Alzheimers Dis %V 66 %P 271-280 %8 2018 %G eng %N 1 %1 http://www.ncbi.nlm.nih.gov/pubmed/30282352?dopt=Abstract %R 10.3233/JAD-180087 %0 Journal Article %J J Alzheimers Dis %D 2018 %T Revolution of Alzheimer Precision Neurology. Passageway of Systems Biology and Neurophysiology. %A Hampel, Harald %A Toschi, Nicola %A Babiloni, Claudio %A Baldacci, Filippo %A Black, Keith L %A Bokde, Arun L W %A Bun, René S %A Cacciola, Francesco %A Cavedo, Enrica %A Chiesa, Patrizia A %A Colliot, Olivier %A Coman, Cristina-Maria %A Dubois, Bruno %A Duggento, Andrea %A Durrleman, Stanley %A Ferretti, Maria-Teresa %A George, Nathalie %A Genthon, Remy %A Habert, Marie-Odile %A Herholz, Karl %A Koronyo, Yosef %A Koronyo-Hamaoui, Maya %A Lamari, Foudil %A Langevin, Todd %A Lehéricy, Stéphane %A Lorenceau, Jean %A Neri, Christian %A Nisticò, Robert %A Nyasse-Messene, Francis %A Ritchie, Craig %A Rossi, Simone %A Santarnecchi, Emiliano %A Sporns, Olaf %A Verdooner, Steven R %A Vergallo, Andrea %A Villain, Nicolas %A Younesi, Erfan %A Garaci, Francesco %A Lista, Simone %K Alzheimer Disease %K Animals %K Brain %K Humans %K Neurology %K Neurophysiology %K Precision Medicine %K Systems Biology %K Translational Medical Research %X

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.

%B J Alzheimers Dis %V 64 %P S47-S105 %8 2018 %G eng %U https://content.iospress.com/download/journal-of-alzheimers-disease/jad179932?id=journal-of-alzheimers-disease%2Fjad179932 %N s1 %1 http://www.ncbi.nlm.nih.gov/pubmed/29562524?dopt=Abstract %R 10.3233/JAD-179932 %0 Journal Article %J J Alzheimers Dis %D 2017 %T Alzheimer's Disease Diagnosis Relies on a Twofold Clinical-Biological Algorithm: Three Memory Clinic Case Reports. %A Levy Nogueira, Marcel %A Samri, Dalila %A Epelbaum, Stéphane %A Lista, Simone %A Suppa, Per %A Spies, Lothar %A Hampel, Harald %A Dubois, Bruno %A Teichmann, Marc %X

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.

%B J Alzheimers Dis %V 60 %P 577-583 %8 2017 %G eng %N 2 %1 http://www.ncbi.nlm.nih.gov/pubmed/28869481?dopt=Abstract %R 10.3233/JAD-170574 %0 Journal Article %J J Alzheimers Dis %D 2017 %T Cerebrospinal Fluid Neurogranin as a Biomarker of Neurodegenerative Diseases: A Cross-Sectional Study. %A Lista, Simone %A Toschi, Nicola %A Baldacci, Filippo %A Zetterberg, Henrik %A Blennow, Kaj %A Kilimann, Ingo %A Teipel, Stefan J %A Cavedo, Enrica %A Dos Santos, Antonio Melo %A Epelbaum, Stéphane %A Lamari, Foudil %A Dubois, Bruno %A Nisticò, Robert %A Floris, Roberto %A Garaci, Francesco %A Hampel, Harald %X

We investigated cerebrospinal fluid (CSF) concentrations of the postsynaptic biomarker neurogranin at baseline in cognitively healthy controls (HC) compared to individuals with mild cognitive impairment (MCI), patients with Alzheimer's disease (AD) dementia, and patients with frontotemporal dementia (FTD). CSF neurogranin was quantified using an in-house immunoassay in a cross-sectional multicenter study of 108 participants [AD dementia (n = 35), FTD (n = 9), MCI (n = 41), cognitively HC (n = 23)]. CSF neurogranin concentrations were significantly higher in AD patients compared with both HC subjects and FTD patients, suggesting that increased CSF neurogranin concentrations may indicate AD-related pathophysiology. CSF neurogranin was independently associated with both total tau and hyperphosphorylated tau proteins, whereas a non-significant correlation with the 42-amino acid-long amyloid-β peptide was evident. CSF neurogranin, however, was not superior to core AD biomarkers in differentiating HC from the three diagnostic groups, and it did not improve their diagnostic accuracy. We conclude that further classification and longitudinal studies are required to shed more light into the potential role of neurogranin as a pathophysiological biomarker of neurodegenerative diseases.

%B J Alzheimers Dis %V 59 %P 1327-1334 %8 2017 %G eng %N 4 %1 http://www.ncbi.nlm.nih.gov/pubmed/28731449?dopt=Abstract %R 10.3233/JAD-170368 %0 Journal Article %J J Alzheimers Dis %D 2017 %T Low Cognitive Awareness, but Not Complaint, is a Good Marker of Preclinical Alzheimer's Disease. %A Cacciamani, Federica %A Tandetnik, Caroline %A Gagliardi, Geoffroy %A Bertin, Hugo %A Habert, Marie-Odile %A Hampel, Harald %A Boukadida, Laurie %A Révillon, Marie %A Epelbaum, Stéphane %A Dubois, Bruno %X

BACKGROUND: Subjective cognitive decline (SCD) may result from many conditions, including Alzheimer's disease (AD).

OBJECTIVE: In this study, we searched for a specific pattern of SCD in asymptomatic individuals at risk for AD.

METHODS: Cognitively normal older adults (N = 318) reporting SCD and their informants were enrolled in the INSIGHT-PreAD cohort. We examined the relationship between six SCD measures and both cognitive scores and AD neuroimaging markers (amyloid burden, hippocampal atrophy and brain hypometabolism). An awareness of cognitive decline index (ACDI) has been introduced based on the subject-informant discrepancy in a questionnaire of SCD and participants with low versus high awareness were compared.

RESULTS: Scores in the INSIGHT-PreAD SCD questionnaires did not correlate with AD neuroimaging markers. As well, no correlation has been found between SCD measures and cognitive scores. Comparing subjects with a low (n = 19) and high (n = 86) level of awareness, no significant difference in terms of demography, neuropsychiatric symptoms, autonomy, quality of life, cognition, and hippocampal volume was found. However, the "low awareness" group showed greater amyloid burden and lower cortical metabolism, compared to the "high awareness" group.

CONCLUSION: This study provided additional evidence that reporting SCD by itself is not a specific symptom of preclinical AD. Conversely, a low cognitive awareness (namely, when subjects report fewer difficulties than their relatives do) may represent a very early form of anosognosia and serve as a specific indicator of preclinical AD. This finding is of key importance as an enrichment factor to consider in both clinical practice and research trials.

%B J Alzheimers Dis %V 59 %P 753-762 %8 2017 %G eng %N 2 %1 http://www.ncbi.nlm.nih.gov/pubmed/28671134?dopt=Abstract %R 10.3233/JAD-170399 %0 Journal Article %J J Alzheimers Dis %D 2017 %T Low Prevalence and Clinical Effect of Vascular Risk Factors in Early-Onset Alzheimer's Disease. %A Chen, Yaohua %A Sillaire, Adeline Rollin %A Dallongeville, Jean %A Skrobala, Emilie %A Wallon, David %A Dubois, Bruno %A Hannequin, Didier %A Pasquier, Florence %X

BACKGROUND: Determinants of early-onset Alzheimer's disease (EOAD) are not well known. In late-onset AD, vascular risk factors (VRFs) are associated with earlier clinical manifestation.

OBJECTIVE: The objective of this study was to assess the putative association between VRFs and EOAD.

METHODS: We studied participants with dementia meeting criteria for EOAD (recruited into the French CoMAJ prospective cohort study from 1 June 2009 to 28 February 2014) and age-, gender-matched controls (ratio 1:3, drawn randomly from the French MONA-LISA population-based survey between 2005 and 2007). Demographic data, VRFs, comorbidities, treatments, and APOE genotypes were compared in multivariable logistic regression analyses.

RESULTS: We studied 102 participants with dementia (mean±standard deviation age: 59.5±3.8; women: 59.8%) and 306 controls. Compared with controls, EOAD participants had spent less time in formal education (9.9±2.9 versus 11.7±3.8 y; p < 0.0001), were less likely to be regular alcohol consumers (p < 0.0001), had a lower body mass index (-2 kg/m2; p < 0.0004), and a lower mean systolic blood pressure (-6.2 mmHg; p = 0.0036). The prevalence of APOE ɛ4 allele was higher in participants with dementia than in controls (50% versus 29.4%; p = 0.0002), as was the prevalence of depression (48% versus 32%; p < 0.001). Similar results were observed in multivariable analysis. Compared with EOAD participants lacking VRFs, EOAD participants with at least one VRF had a higher prevalence of depression (29.6% versus 53.3%, respectively; p = 0.03).

CONCLUSION: The prevalence of VRFs is not elevated in EOAD patients (in contrast to older AD patients). Extensive genetic testing should be considered more frequently in the context of EOAD.

%B J Alzheimers Dis %V 60 %P 1045-1054 %8 2017 %G eng %N 3 %1 http://www.ncbi.nlm.nih.gov/pubmed/28984595?dopt=Abstract %R 10.3233/JAD-170367 %0 Journal Article %J J Alzheimers Dis %D 2016 %T Comparison of Different Matrices as Potential Quality Control Samples for Neurochemical Dementia Diagnostics. %A Lelental, Natalia %A Brandner, Sebastian %A Kofanova, Olga %A Blennow, Kaj %A Zetterberg, Henrik %A Andreasson, Ulf %A Engelborghs, Sebastiaan %A Mroczko, Barbara %A Gabryelewicz, Tomasz %A Teunissen, Charlotte %A Mollenhauer, Brit %A Parnetti, Lucilla %A Chiasserini, Davide %A Molinuevo, José Luis %A Perret-Liaudet, Armand %A Verbeek, Marcel M %A Andreasen, Niels %A Brosseron, Frederic %A Bahl, Justyna M C %A Herukka, Sanna-Kaisa %A Hausner, Lucrezia %A Frölich, Lutz %A Labonte, Anne %A Poirier, Judes %A Miller, Anne-Marie %A Zilka, Norbert %A Kovacech, Branislav %A Urbani, Andrea %A Suardi, Silvia %A Oliveira, Catarina %A Baldeiras, Ines %A Dubois, Bruno %A Rot, Uros %A Lehmann, Sylvain %A Skinningsrud, Anders %A Betsou, Fay %A Wiltfang, Jens %A Gkatzima, Olymbia %A Winblad, Bengt %A Buchfelder, Michael %A Kornhuber, Johannes %A Lewczuk, Piotr %K Amyloid beta-Peptides %K Animals %K Anti-Bacterial Agents %K Biomarkers %K Cattle %K Clinical Chemistry Tests %K Dementia %K Humans %K Peptide Fragments %K Quality Control %K Reference Standards %K Serum Albumin, Bovine %K Sodium Azide %K tau Proteins %K Time Factors %K Tissue Preservation %X

BACKGROUND: Assay-vendor independent quality control (QC) samples for neurochemical dementia diagnostics (NDD) biomarkers are so far commercially unavailable. This requires that NDD laboratories prepare their own QC samples, for example by pooling leftover cerebrospinal fluid (CSF) samples.

OBJECTIVE: To prepare and test alternative matrices for QC samples that could facilitate intra- and inter-laboratory QC of the NDD biomarkers.

METHODS: Three matrices were validated in this study: (A) human pooled CSF, (B) Aβ peptides spiked into human prediluted plasma, and (C) Aβ peptides spiked into solution of bovine serum albumin in phosphate-buffered saline. All matrices were tested also after supplementation with an antibacterial agent (sodium azide). We analyzed short- and long-term stability of the biomarkers with ELISA and chemiluminescence (Fujirebio Europe, MSD, IBL International), and performed an inter-laboratory variability study.

RESULTS: NDD biomarkers turned out to be stable in almost all samples stored at the tested conditions for up to 14 days as well as in samples stored deep-frozen (at - 80°C) for up to one year. Sodium azide did not influence biomarker stability. Inter-center variability of the samples sent at room temperature (pooled CSF, freeze-dried CSF, and four artificial matrices) was comparable to the results obtained on deep-frozen samples in other large-scale projects.

CONCLUSION: Our results suggest that it is possible to replace self-made, CSF-based QC samples with large-scale volumes of QC materials prepared with artificial peptides and matrices. This would greatly facilitate intra- and inter-laboratory QC schedules for NDD measurements.

%B J Alzheimers Dis %V 52 %P 51-64 %8 2016 03 01 %G eng %N 1 %1 http://www.ncbi.nlm.nih.gov/pubmed/26967210?dopt=Abstract %R 10.3233/JAD-150883 %0 Journal Article %J J Alzheimers Dis %D 2016 %T Functional Connectivity of Ventral and Dorsal Visual Streams in Posterior Cortical Atrophy. %A Migliaccio, Raffaella %A Gallea, Cécile %A Kas, Aurélie %A Perlbarg, Vincent %A Samri, Dalila %A Trotta, Laura %A Michon, Agnès %A Lacomblez, Lucette %A Dubois, Bruno %A Lehéricy, Stéphane %A Bartolomeo, Paolo %K Aged %K Alzheimer Disease %K Atrophy %K Case-Control Studies %K Cerebral Cortex %K Female %K Humans %K Image Processing, Computer-Assisted %K Magnetic Resonance Imaging %K Male %K Mental Status Schedule %K Middle Aged %K Neuropsychological Tests %K Oxygen %K Visual Pathways %X

BACKGROUND: Posterior cortical atrophy (PCA) induces progressive dysfunction of ventral and dorsal visual networks. Little is known, however, about corresponding changes in functional connectivity (FC).

OBJECTIVES: To investigate FC changes in the visual networks, their relationship with cortical atrophy, and the association with Alzheimer's disease (AD) pathology.

METHODS: Ten PCA patients and 28 age-matched controls participated in the study. Using resting state fMRI, we measured FC in ventral and dorsal cortical visual networks, defined on the basis of a priori knowledge of long-range white matter connections. To assess the relationships with AD, we determined AD biomarkers in cerebrospinal fluid and FC in the default mode network (DMN), which is vulnerable to AD pathology. Voxel-based morphometry analysis assessed the pattern of grey matter (GM) atrophy.

RESULTS: PCA patients showed GM atrophy in bilateral occipital and inferior parietal regions. PCA patients had lower FC levels in a ventral network than controls, but higher FC in inferior components of the dorsal network. In particular, the increased connectivity correlated with greater GM atrophy in occipital regions. All PCA patients had positive cerebrospinal fluid biomarkers for AD; however, FC in global DMN did not differ from controls.

CONCLUSIONS: FC in PCA reflects brain structure in a non-univocal way. Hyperconnectivity of dorsal networks may indicate aberrant communication in response to posterior brain atrophy or processes of neural resilience during the initial stage of brain dysfunction. The lack of difference from controls in global DMN FC highlights the atypical nature of PCA with respect to typical AD.

%B J Alzheimers Dis %V 51 %P 1119-30 %8 2016 %G eng %N 4 %1 http://www.ncbi.nlm.nih.gov/pubmed/26923019?dopt=Abstract %R 10.3233/JAD-150934 %0 Journal Article %J J Alzheimers Dis %D 2016 %T Performance of Hippocampus Volumetry with FSL-FIRST for Prediction of Alzheimer's Disease Dementia in at Risk Subjects with Amnestic Mild Cognitive Impairment. %A Suppa, Per %A Hampel, Harald %A Kepp, Timo %A Lange, Catharina %A Spies, Lothar %A Fiebach, Jochen B %A Dubois, Bruno %A Buchert, Ralph %K Aged %K Aging %K Alzheimer Disease %K Area Under Curve %K Cognitive Dysfunction %K Databases, Factual %K Disease Progression %K Hippocampus %K Humans %K Image Interpretation, Computer-Assisted %K Magnetic Resonance Imaging %K Neuropsychological Tests %K Organ Size %K Pattern Recognition, Automated %K Prognosis %K Reproducibility of Results %K Risk %K ROC Curve %K Sensitivity and Specificity %K Time Factors %X

MRI-based hippocampus volume, a core feasible biomarker of Alzheimer's disease (AD), is not yet widely used in clinical patient care, partly due to lack of validation of software tools for hippocampal volumetry that are compatible with routine workflow. Here, we evaluate fully-automated and computationally efficient hippocampal volumetry with FSL-FIRST for prediction of AD dementia (ADD) in subjects with amnestic mild cognitive impairment (aMCI) from phase 1 of the Alzheimer's Disease Neuroimaging Initiative. Receiver operating characteristic analysis of FSL-FIRST hippocampal volume (corrected for head size and age) revealed an area under the curve of 0.79, 0.70, and 0.70 for prediction of aMCI-to-ADD conversion within 12, 24, or 36 months, respectively. Thus, FSL-FIRST provides about the same power for prediction of progression to ADD in aMCI as other volumetry methods.

%B J Alzheimers Dis %V 51 %P 867-73 %8 2016 %G eng %N 3 %1 http://www.ncbi.nlm.nih.gov/pubmed/26923010?dopt=Abstract %R 10.3233/JAD-150804 %0 Journal Article %J J Alzheimers Dis %D 2016 %T So Close Yet So Far: Executive Contribution to Memory Processing in Behavioral Variant Frontotemporal Dementia. %A Bertoux, Maxime %A Ramanan, Siddharth %A Slachevsky, Andrea %A Wong, Stephanie %A Henriquez, Fernando %A Musa, Gada %A Delgado, Carolina %A Flanagan, Emma %A Bottlaender, Michel %A Sarazin, Marie %A Hornberger, Michael %A Dubois, Bruno %X

BACKGROUND: Memory impairment in behavioral variant frontotemporal dementia (bvFTD) is traditionally considered to be mild and attributed to prefrontal cortex dysfunction. Recent studies, however, indicated that some patients can present with a memory impairment of the hippocampal type, showing storage and consolidation deficits in addition to the more executive/prefrontal related encoding and strategic difficulties.

OBJECTIVE: This study aimed to study the relationship between executive functions (EF) and memory processes in bvFTD via a data-driven approach.

METHOD: Participants consisted of 71 bvFTD (among which 60.6% had a lumbar puncture showing non-Alzheimer biomarker profile) and 60 controls (among which 45% had amyloid imaging showing a normal profile). EF were assessed by the Frontal Assessment Battery, semantic/lexical verbal fluency tests, and forward/backward digit spans. Patients were split into amnestic (n = 33) and non-amnestic (n = 38) subgroups based on normative data (total recall score) from the Free and Cued Selective Reminding Test (FCSRT). Relationships between FCSRT subscores and EF measures were explored through hierarchical clustering analysis, partial correlation analysis with an EF component, and automated linear modeling.

RESULTS: Convergent findings across the statistical approaches show that, overall, memory performance was independent from EF in bvFTD whereas the relationship was stronger in controls. Indeed, in bvFTD, memory performance did not cluster with EF, was not correlated with the EF component, and was only partially (4% - 12.7%) predicted by EF.

DISCUSSION: These findings show that executive dysfunctions cannot solely explain the memory deficits occurring in bvFTD. Indeed, some patients present with a genuine amnesia affecting storage and consolidation abilities, which are independent from executive dysfunctions. On the clinical level, this study highlights the importance of revising the neuropsychological diagnosis criteria for bvFTD.

%B J Alzheimers Dis %V 54 %P 1005-1014 %8 2016 Oct 04 %G eng %N 3 %1 http://www.ncbi.nlm.nih.gov/pubmed/27567869?dopt=Abstract %R 10.3233/JAD-160522 %0 Journal Article %J J Alzheimers Dis %D 2016 %T Social Cognition Deficits: The Key to Discriminate Behavioral Variant Frontotemporal Dementia from Alzheimer's Disease Regardless of Amnesia? %A Bertoux, Maxime %A de Souza, Leonardo Cruz %A O'Callaghan, Claire %A Greve, Andrea %A Sarazin, Marie %A Dubois, Bruno %A Hornberger, Michael %K Aged %K Alzheimer Disease %K Amnesia %K Cognition %K Diagnosis, Differential %K Emotions %K Female %K Frontotemporal Dementia %K Humans %K Male %K Memory, Episodic %K Neuropsychological Tests %K Social Perception %X

Relative sparing of episodic memory is a diagnostic criterion of behavioral variant frontotemporal dementia (bvFTD). However, increasing evidence suggests that bvFTD patients can show episodic memory deficits at a similar level as Alzheimer's disease (AD). Social cognition tasks have been proposed to distinguish bvFTD, but no study to date has explored the utility of such tasks for the diagnosis of amnestic bvFTD. Here, we contrasted social cognition performance of amnestic and non-amnestic bvFTD from AD, with a subgroup having confirmed in vivo pathology markers. Ninety-six participants (38 bvFTD and 28 AD patients as well as 30 controls) performed the short Social-cognition and Emotional Assessment (mini-SEA). BvFTD patients were divided into amnestic versus non-amnestic presentation using the validated Free and Cued Selective Reminding Test (FCSRT) assessing episodic memory. As expected, the accuracy of the FCSRT to distinguish the overall bvFTD group from AD was low (69.7% ) with ∼50% of bvFTD patients being amnestic. By contrast, the diagnostic accuracy of the mini-SEA was high (87.9% ). When bvFTD patients were split on the level of amnesia, mini-SEA diagnostic accuracy remained high (85.1% ) for amnestic bvFTD versus AD and increased to very high (93.9% ) for non-amnestic bvFTD versus AD. Social cognition deficits can distinguish bvFTD and AD regardless of amnesia to a high degree and provide a simple way to distinguish both diseases at presentation. These findings have clear implications for the diagnostic criteria of bvFTD. They suggest that the emphasis should be on social cognition deficits with episodic memory deficits not being a helpful diagnostic criterion in bvFTD.

%B J Alzheimers Dis %V 49 %P 1065-74 %8 2016 %G eng %N 4 %1 http://www.ncbi.nlm.nih.gov/pubmed/26756325?dopt=Abstract %R 10.3233/JAD-150686 %0 Journal Article %J J Alzheimers Dis %D 2016 %T Timely Diagnosis for Alzheimer's Disease: A Literature Review on Benefits and Challenges. %A Dubois, Bruno %A Padovani, Alessandro %A Scheltens, Philip %A Rossi, Andrea %A Dell'Agnello, Grazia %K Alzheimer Disease %K Databases, Bibliographic %K Humans %K Time Factors %X

BACKGROUND: Timely diagnosis of Alzheimer's disease (AD) refers to a diagnosis at the stage when patients come to the attention of clinicians because of concerns about changes in cognition, behavior, or functioning and can be still free of dementia and functionally independent.

OBJECTIVES: To comprehensively review existing scientific evidence on the benefits and potential challenges of making a timely diagnosis of AD.

METHODS: Relevant studies were identified by searching electronic databases (Medline, Embase) and bibliographies for studies published in English between 1 January 2000 and 2 June 2014 on the consequences of a timely diagnosis of AD.

RESULTS: Nine studies were identified that investigated the consequences of diagnosing AD at the initial stages; none were specifically focused on prodromal AD. A timely diagnosis potentially offers the opportunities of early intervention, implementation of coordinated care plans, better management of symptoms, patient safety, cost savings, and postponement of institutionalization. Barriers to making a timely diagnosis include stigma, suicide risk, lack of training, diagnostic uncertainty, shortage of specialized diagnostic services, and the reluctance of healthcare providers to make a diagnosis when no effective disease-modifying options are available.

CONCLUSIONS: Despite its potential benefits, few published studies have explored the advantages or risks of a timely diagnosis of AD. In light of the cultural shift toward diagnosis at the initial stage of the disease continuum, when the patient does not yet have dementia, more investigations are needed to evaluate the benefits and address the barriers that may impede making a timely AD diagnosis.

%B J Alzheimers Dis %V 49 %P 617-31 %8 2016 %G eng %N 3 %1 http://www.ncbi.nlm.nih.gov/pubmed/26484931?dopt=Abstract %R 10.3233/JAD-150692 %0 Journal Article %J Lancet Neurol %D 2014 %T Advancing research diagnostic criteria for Alzheimer's disease: the IWG-2 criteria. %A Dubois, Bruno %A Feldman, Howard H %A Jacova, Claudia %A Hampel, Harald %A Molinuevo, José Luis %A Blennow, Kaj %A DeKosky, Steven T %A Gauthier, Serge %A Selkoe, Dennis %A Bateman, Randall %A Cappa, Stefano %A Crutch, Sebastian %A Engelborghs, Sebastiaan %A Frisoni, Giovanni B %A Fox, Nick C %A Galasko, Douglas %A Habert, Marie-Odile %A Jicha, Gregory A %A Nordberg, Agneta %A Pasquier, Florence %A Rabinovici, Gil %A Robert, Philippe %A Rowe, Christopher %A Salloway, Stephen %A Sarazin, Marie %A Epelbaum, Stéphane %A de Souza, Leonardo C %A Vellas, Bruno %A Visser, Pieter J %A Schneider, Lon %A Stern, Yaakov %A Scheltens, Philip %A Cummings, Jeffrey L %K Alzheimer Disease %K Biomarkers %K Humans %K International Cooperation %K Phenotype %K Practice Guidelines as Topic %K Societies, Medical %X

In the past 8 years, both the International Working Group (IWG) and the US National Institute on Aging-Alzheimer's Association have contributed criteria for the diagnosis of Alzheimer's disease (AD) that better define clinical phenotypes and integrate biomarkers into the diagnostic process, covering the full staging of the disease. This Position Paper considers the strengths and limitations of the IWG research diagnostic criteria and proposes advances to improve the diagnostic framework. On the basis of these refinements, the diagnosis of AD can be simplified, requiring the presence of an appropriate clinical AD phenotype (typical or atypical) and a pathophysiological biomarker consistent with the presence of Alzheimer's pathology. We propose that downstream topographical biomarkers of the disease, such as volumetric MRI and fluorodeoxyglucose PET, might better serve in the measurement and monitoring of the course of disease. This paper also elaborates on the specific diagnostic criteria for atypical forms of AD, for mixed AD, and for the preclinical states of AD.

%B Lancet Neurol %V 13 %P 614-29 %8 2014 Jun %G eng %N 6 %1 http://www.ncbi.nlm.nih.gov/pubmed/24849862?dopt=Abstract %R 10.1016/S1474-4422(14)70090-0 %0 Journal Article %J Alzheimers Dement %D 2011 %T The diagnosis of mild cognitive impairment due to Alzheimer's disease: recommendations from the National Institute on Aging-Alzheimer's Association workgroups on diagnostic guidelines for Alzheimer's disease. %A Albert, Marilyn S %A DeKosky, Steven T %A Dickson, Dennis %A Dubois, Bruno %A Feldman, Howard H %A Fox, Nick C %A Gamst, Anthony %A Holtzman, David M %A Jagust, William J %A Petersen, Ronald C %A Snyder, Peter J %A Carrillo, Maria C %A Thies, Bill %A Phelps, Creighton H %K Alzheimer Disease %K Biomarkers %K Cognition Disorders %K Diagnosis, Differential %K Diagnostic Imaging %K Humans %K National Institute on Aging (U.S.) %K Practice Guidelines as Topic %K Societies, Medical %K United States %X

The National Institute on Aging and the Alzheimer's Association charged a workgroup with the task of developing criteria for the symptomatic predementia phase of Alzheimer's disease (AD), referred to in this article as mild cognitive impairment due to AD. The workgroup developed the following two sets of criteria: (1) core clinical criteria that could be used by healthcare providers without access to advanced imaging techniques or cerebrospinal fluid analysis, and (2) research criteria that could be used in clinical research settings, including clinical trials. The second set of criteria incorporate the use of biomarkers based on imaging and cerebrospinal fluid measures. The final set of criteria for mild cognitive impairment due to AD has four levels of certainty, depending on the presence and nature of the biomarker findings. Considerable work is needed to validate the criteria that use biomarkers and to standardize biomarker analysis for use in community settings.

%B Alzheimers Dement %V 7 %P 270-9 %8 2011 May %G eng %N 3 %1 http://www.ncbi.nlm.nih.gov/pubmed/21514249?dopt=Abstract %R 10.1016/j.jalz.2011.03.008