Correlation between serum 25-hydroxyvitamin D concentrations and regional cerebral blood flow in degenerative dementia

Background Chronic low serum vitamin D concentrations are common among the elderly. Recent studies have suggested that its metabolite, 25-hydroxyvitamin D (25-OHD), might be important for preserving cognitive functions through specific brain protective effects. However, this hypothesis is still under discussion. The aim of this study was to assess the correlation between serum 25-OHD concentrations and regional cerebral blood flow in neurodegenerative diseases such as Alzheimer's disease (AD) and dementia of Lewy bodies (DLB). Patients and methods Radionuclide brain single-photon emission computed tomography/computed tomography (SPECT/CT) images and 25-OHD dosage in noninstitutionalized patients were obtained within 14 days. SPECT/CT examination was carried out using technetium-99m-ethyl cysteinate dimer in 20 consecutive patients (12 AD and eight DLB). Reconstructed images were spatially normalized using Statistical Parametric Mapping version 5 software to a default SPECT template. Voxel-based multiple regression correlation analyses, with age and mini mental state examination scores as confounding factors, were carried out. Findings were considered significant for a threshold P-value less than 0.01 (corrected at cluster level). Results A positive correlation was found between 25-OHD concentrations and regional cerebral blood flow in the left precuneus cortex (Talairach coordinates: -14, -42, 63) in AD patients. No correlation was detected in DLB patients. Conclusion The results of this study confirm the relationship between 25-OHD concentrations and AD and therefore underline the hypothesis of a potential neuroprotective effect against brain degeneration. These encouraging findings need to be confirmed by larger prospective correlation series. Nucl Med Commun 33:1048-1052 (C) 2012 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins

Twenty‐year trends in patient referrals throughout the creation and development of a regional memory clinic network

Introduction: Memory clinics (MCs) are the main model for dementia diagnosis and care. Following the development of a MC network in Northern France, our objectives were to assess its impact on patient characteristics over 20 years.Methods: The characteristics of new consultants were studied from 1997 to 2016.Results: New consultants increased from 774 per year in 1997 to 26258 per year in 2016, as the number of MCs increased from 12 to 29. Over time, patients were progressively older and less educated, and more were living alone. A greater proportion of patients were referred by specialists. Referral delay and home-to-MC distance kept decreasing. The oldest patients were referred at a progressively less-severe stage. The proportion of young patients kept increasing in the tertiary referral center.Discussions: The development of a region-wide MC network led to increased referral of vulnerable patients and differentiation of the tertiary referral center over time

Distribution of Cerebrospinal Fluid Biomarker Profiles in Patients Explored for Cognitive Disorders

CSF Alzheimer's disease (AD) biomarkers allow classifying individuals based on their levels of amyloid and neurodegeneration pathologies

Primary Progressive Aphasia in the Network of French Alzheimer Plan Memory Centers.

Few demographical data about primary progressive aphasia (PPA) are available, and most knowledge regarding PPA is based on tertiary centers' results. Our aims were to describe demographical characteristics of the PPA population in a large sample of PPA patients from the network of French Alzheimer plan memory centers (Sample 1), and to describe the stratification of cerebrospinal fluid (CSF) biomarkers in two different samples of PPA patients (Samples 2 and 3). All registered PPA patients in the French Alzheimer's disease (AD) databank (Sample 1: n = 2,035) and a subsample (Sample 2: n = 65) derived from a multicentric prospective cohort with CSF biomarker analysis were analyzed. A multicentric retrospective cohort from language expert tertiary centers (Sample 3: n = 97) with CSF biomarker analysis was added. Sample 3 was added to replicate the CSF results of the Sample 2 and to evaluate repartition of AD pathology in the three variant of PPA according to the latest classification. Non-Fluent/Agrammatic, Logopenic, and Unclassifiable PPA patients (NF/A-Logo-Unclass PPA) were older and more frequent than Semantic PPA patients (2.2 versus 0.8/100,000 inhabitants; p < 0.00001). Male predominance occurred after the age of 80 (p < 0.00001). A higher level of education was observed in the PPA population compared to a typical amnesic AD group. No demographical significant difference between PPA due to AD and not due to AD was observed. The Logopenic variant was most frequent with 85% of AD CSF biomarker profiles (35% in NF/A PPA; 20% in Semantic PPA). PPA occurs also in an elderly population, especially in male patients over 80. CSF biomarkers are useful to stratify PPA. The epidemiology of PPA should be further investigated to confirm gender and cognitive reserve role in PPA to better understand the factors and mechanisms leading to this language-predominant deficit during neurodegenerative diseases

Primary Progressive Aphasia in the Network of French Alzheimer Plan Memory Centers

International audienceBACKGROUND:Few demographical data about primary progressive aphasia (PPA) are available, and most knowledge regarding PPA is based on tertiary centers' results.OBJECTIVE:Our aims were to describe demographical characteristics of the PPA population in a large sample of PPA patients from the network of French Alzheimer plan memory centers (Sample 1), and to describe the stratification of cerebrospinal fluid (CSF) biomarkers in two different samples of PPA patients (Samples 2 and 3).METHODS:All registered PPA patients in the French Alzheimer's disease (AD) databank (Sample 1: n = 2,035) and a subsample (Sample 2: n = 65) derived from a multicentric prospective cohort with CSF biomarker analysis were analyzed. A multicentric retrospective cohort from language expert tertiary centers (Sample 3: n = 97) with CSF biomarker analysis was added. Sample 3 was added to replicate the CSF results of the Sample 2 and to evaluate repartition of AD pathology in the three variant of PPA according to the latest classification.RESULTS:Non-Fluent/Agrammatic, Logopenic, and Unclassifiable PPA patients (NF/A-Logo-Unclass PPA) were older and more frequent than Semantic PPA patients (2.2 versus 0.8/100,000 inhabitants; p < 0.00001). Male predominance occurred after the age of 80 (p < 0.00001). A higher level of education was observed in the PPA population compared to a typical amnesic AD group. No demographical significant difference between PPA due to AD and not due to AD was observed. The Logopenic variant was most frequent with 85% of AD CSF biomarker profiles (35% in NF/A PPA; 20% in Semantic PPA).CONCLUSION:PPA occurs also in an elderly population, especially in male patients over 80. CSF biomarkers are useful to stratify PPA. The epidemiology of PPA should be further investigated to confirm gender and cognitive reserve role in PPA to better understand the factors and mechanisms leading to this language-predominant deficit during neurodegenerative diseases

Plasma Amyloid Beta Predicts Conversion to Dementia in Subjects with Mild Cognitive Impairment: The BALTAZAR Study

International audienceINTRODUCTION: Blood-based biomarkers are the next challenge for Alzheimer's disease (AD) diagnosis and prognosis. METHODS: Mild cognitive impairment (MCI) participants (N = 485) of the BALTAZAR study, a large-scale longitudinal multicenter cohort, were followed-up for 3 years. A total of 165 of them converted to dementia (95% AD). Associations of conversion and plasma amyloid beta (Aβ)1-42 , Aβ1-40 , Aβ1-42 /Aβ1-40 ratio were analyzed with logistic and Cox models. RESULTS: Converters to dementia had lower level of plasma Aβ1-42 (37.1 pg/mL [12.5] vs. 39.2 [11.1] , P value = .03) and lower Aβ1-42 /Aβ1-40 ratio than non-converters (0.148 [0.125] vs. 0.154 [0.076], P value = .02). MCI participants in the highest quartile of Aβ1-42 /Aβ1-40 ratio (>0.169) had a significant lower risk of conversion (hazard ratio adjusted for age, sex, education, apolipoprotein E \epsilon4, hippocampus atrophy = 0.52 (95% confidence interval [0.31-0.86], P value = .01). DISCUSSION: In this large cohort of MCI subjects we identified a threshold for plasma Aβ1-42 /Aβ1-40 ratio that may detect patients with a low risk of conversion to dementia within 3 years

Plasma amyloid levels within the Alzheimer's process and correlations with central biomarkers

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Plasma amyloid levels within the Alzheimer's process and correlations with central biomarkers

International audienceINTRODUCTION:Diagnostic relevance of plasma amyloid β (Aβ) for Alzheimer's disease (AD) process yields conflicting results. The objective of the study was to assess plasma levels of Aβ42 and Aβ40 in amnestic mild cognitive impairment (MCI), nonamnestic MCI, and AD patients and to investigate relationships between peripheral and central biomarkers.METHODS:One thousand forty participants (417 amnestic MCI, 122 nonamnestic MCI, and 501 AD) from the Biomarker of AmyLoïd pepTide and AlZheimer's diseAse Risk multicenter prospective study with cognition, plasma, cerebrospinal fluid (CSF), and magnetic resonance imaging assessments were included.RESULTS:Plasma Aβ1-42 and Aβ1-40 were lower in AD (36.9 [11.7] and 263 [80] pg/mL) than in amnestic MCI (38.2 [11.9] and 269 [68] pg/mL) than in nonamnestic MCI (39.7 [10.5] and 272 [52] pg/mL), respectively (P = .01 for overall difference between groups for Aβ1-42 and P = .04 for Aβ1-40). Globally, plasma Aβ1-42 correlated with age, Mini-Mental State Examination, and APOE ε4 allele. Plasma Aβ1-42 correlated with all CSF biomarkers in MCI but only with CSF Aβ42 in AD.DISCUSSION:Plasma Aβ was associated with cognitive status and CSF biomarkers, suggesting the interest of plasma amyloid biomarkers for diagnosis purpose.Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved