%0 Journal Article %J J Alzheimers Dis %D 2021 %T Cerebrospinal Fluid Amyloid-β Oligomer Levels in Patients with Idiopathic Normal Pressure Hydrocephalus. %A Kawamura, Kaito %A Miyajima, Masakazu %A Nakajima, Madoka %A Kanai, Mitsuyasu %A Motoi, Yumiko %A Nojiri, Shuko %A Akiba, Chihiro %A Ogino, Ikuko %A Xu, Hanbing %A Kamohara, Chihiro %A Yamada, Shinya %A Karagiozov, Kostadin %A Ikeuchi, Takeshi %A Kondo, Akihide %A Arai, Hajime %X

BACKGROUND: The amyloid-β oligomers, consisting of 10-20 monomers (AβO10-20), have strong neurotoxicity and are associated with cognitive impairment in Alzheimer's disease (AD). However, their role in patients with idiopathic normal pressure hydrocephalus (iNPH) is poorly understood.

OBJECTIVE: We hypothesized that cerebrospinal fluid (CSF) AβO10-20 accumulates in patients with iNPH, and its clearance after CSF shunting contributes to neurological improvement. We measured CSF AβO10-20 levels before and after CSF shunting in iNPH patients evaluating their diagnostic and prognostic role.

METHODS: We evaluated two iNPH cohorts: "evaluation" (cohort-1) with 32 patients and "validation" (cohort-2) with 13 patients. Comparison cohorts included: 27 neurologically healthy controls (HCs), and 16 AD, 15 Parkinson's disease (PD), and 14 progressive supranuclear palsy (PSP) patients. We assessed for all cohorts CSF AβO10-20 levels and their comprehensive clinical data. iNPH cohort-1 pre-shunting data were compared with those of comparison cohorts, using cohort-2 for validation. Next, we compared cohort-1's clinical and CSF data: 1) before and after CSF shunting, and 2) increased versus decreased AβO10-20 levels at baseline, 1 and 3 years after shunting.

RESULTS: Cohort-1 had higher CSF AβO10-20 levels than the HCs, PD, and PSP cohorts. This result was validated with data from cohort-2. CSF AβO10-20 levels differentiated cohort-1 from the PD and PSP groups, with an area under receiver operating characteristic curve of 0.94. AβO10-20 levels in cohort-1 decreased after CSF shunting. Patients with AβO10-20 decrease showed better cognitive outcome than those without.

CONCLUSION: AβO10-20 accumulates in patients with iNPH and is eliminated by CSF shunting. AβO10-20 can be an applicable diagnostic and prognostic biomarker.

%B J Alzheimers Dis %V 83 %P 179-190 %8 2021 Aug 31 %G eng %N 1 %R 10.3233/JAD-210226 %0 Journal Article %J J Alzheimers Dis %D 2018 %T Change of Amyloid-β 1-42 Toxic Conformer Ratio After Cerebrospinal Fluid Diversion Predicts Long-Term Cognitive Outcome in Patients with Idiopathic Normal Pressure Hydrocephalus. %A Akiba, Chihiro %A Nakajima, Madoka %A Miyajima, Masakazu %A Ogino, Ikuko %A Motoi, Yumiko %A Kawamura, Kaito %A Adachi, Satoshi %A Kondo, Akihide %A Sugano, Hidenori %A Tokuda, Takahiko %A Irie, Kazuhiro %A Arai, Hajime %X

BACKGROUND: Alzheimer's disease (AD) pathology in idiopathic normal pressure hydrocephalus (iNPH) contributes to poor shunt responses. Amyloid-β 1- 42 (Aβ42) toxic conformer was recently identified with features of rapid oligomerization, strong neurotoxicity and synaptotoxicity.

OBJECTIVE: This observational study points to Aβ42 toxic conformer as a biomarker for AD pathology and for poor postoperative prognosis in patients with iNPH.

METHODS: The first cohort consisted of patients with AD (n = 17) and iNPH (n = 17), and cognitively normal individuals (CN, n = 12). The second cohort, consisted of 51 patients with iNPH, was divided into two groups according to phosphorylated Tau (pTau) level (low- and high-pTau groups); the low-pTau group was further subdivided according to one-year postoperative change in Aβ42 toxic conformer ratio (%) [Aβ42 toxic conformer/Aβ42×100] (decreased- and increased-conformer subgroups). Enzyme-linked immunosorbent assay was used to measure pTau, Aβ42, and Aβ42 toxic conformer in cerebrospinal fluid. Outcomes were evaluated using neuropsychological tests one- and two-years postoperatively.

RESULTS: In the first cohort, Aβ42 toxic conformer ratio in the iNPH group (10.8%) was significantly higher than that in the CN group (6.3%) and significantly lower than that in the AD group (17.2%). In the second cohort, the high-pTau group showed cognitive decline two-years postoperatively compared to baseline. However, the low-pTau group showed favorable outcomes one-year postoperatively; furthermore, the increased-conformer subgroup showed cognitive decline two-years postoperatively while the decreased-conformer subgroup maintained the improvement.

CONCLUSIONS: Change in Aβ42 toxic conformer ratio predicts long-term cognitive outcome in iNPH, even in the low-pTau group.

%B J Alzheimers Dis %V 63 %P 989-1002 %8 2018 %G eng %N 3 %1 http://www.ncbi.nlm.nih.gov/pubmed/29710721?dopt=Abstract %R 10.3233/JAD-180059 %0 Journal Article %J J Alzheimers Dis %D 2018 %T Preoperative Phosphorylated Tau Concentration in the Cerebrospinal Fluid Can Predict Cognitive Function Three Years after Shunt Surgery in Patients with Idiopathic Normal Pressure Hydrocephalus. %A Nakajima, Madoka %A Miyajima, Masakazu %A Ogino, Ikuko %A Akiba, Chihiro %A Kawamura, Kaito %A Kamohara, Chihiro %A Fusegi, Keiko %A Harada, Yoshinao %A Hara, Takeshi %A Sugano, Hidenori %A Tange, Yuichi %A Karagiozov, Kostadin %A Kasuga, Kensaku %A Ikeuchi, Takeshi %A Tokuda, Takahiko %A Arai, Hajime %X

BACKGROUND: Idiopathic normal pressure hydrocephalus (iNPH) is commonly treated by cerebrospinal fluid (CSF) shunting. However, the long-term efficacy of shunt intervention in the presence of comorbid Alzheimer's disease (AD) pathology is debated.

OBJECTIVE: To identify AD-associated CSF biomarkers predictive of shunting surgery outcomes in patients with iNPH.

METHODS: Preoperative levels of total and phosphorylated Tau (p-Tau) were measured in 40 patients with iNPH divided into low (<30 pg/mL) and high (≥30 pg/mL) p-Tau groups and followed up for three years after lumboperitoneal shunting. The modified Rankin Scale (mRS), Mini-Mental State Examination (MMSE), Frontal Assessment Battery, and iNPH Grading Scale scores were compared between the age-adjusted low (n = 24; mean age 75.7 years [SD 5.3]) and high (n = 11; mean age 76.0 years [SD 5.6]) p-Tau groups.

RESULTS: Cognitive function improved early in the low p-Tau group and was maintained thereafter (p = 0.005). In contrast, the high p-Tau group showed a gradual decline to baseline levels by the third postoperative year (p = 0.040). Although the p-Tau concentration did not correlate with the preoperative MMSE score, a negative correlation appeared and strengthened during follow-up (R2 = 0.352, p < 0.001). Furthermore, the low p-Tau group showed rapid and sustained mRS grade improvement, whereas mRS performance gradually declined in the high p-Tau group.

CONCLUSIONS: Preoperative CSF p-Tau concentration predicted some aspects of cognitive function after shunt intervention in patients with iNPH. The therapeutic effects of shunt treatment were shorter-lasting in patients with coexisting AD pathology.

%B J Alzheimers Dis %V 66 %P 319-331 %8 2018 %G eng %N 1 %1 http://www.ncbi.nlm.nih.gov/pubmed/30248058?dopt=Abstract %R 10.3233/JAD-180557