Search results for "ALZHEIMER"
showing 10 items of 706 documents
Physical Activity and Amyloid-β Brain Levels in Elderly Adults with Intact Cognition and Mild Cognitive Impairment
2015
Objectives To examine the associations between amyloid-β brain deposition and physical activity (PA) in elderly adults without dementia and to investigate whether the association has a dose-response relationship. Design Cross-sectional study. Setting French community-dwelling people. Participants Elderly adults with normal or mildly impaired cognition (mean age 74.7 ± 4.2; 60.4% female) with available information on current self-reported PA and amyloid-β brain deposition measured using positron emission tomography (PET) using the PET-ligand florbetapir F 18 (n = 268). Measurements A standardized uptake value ratio (SUVR) was obtained for each subject. Participants were divided according to …
Neurogranin as a Novel Biomarker in Alzheimer's Disease
2020
Abstract Background In this study, we investigated the possible role of 2 novel biomarkers of synaptic damage, namely, neurogranin and α-synuclein, in Alzheimer disease (AD). Methods The study was performed in a cohort consisting of patients with AD and those without AD, including individuals with other neurological diseases. Cerebrospinal fluid (CSF) neurogranin and α-synuclein levels were measured by sensitive enzyme-linked immunosorbent assays (ELISAs). Results We found significantly increased levels of CSF neurogranin and α-synuclein in patients with AD than those without AD. Neurogranin was correlated with total tau (tTau) and phosphorylated tau (pTau), as well as with cognitive declin…
The EADC-ADNI Harmonized Protocol for manual hippocampal segmentation on magnetic resonance : Evidence of validity
2014
BackgroundAn international Delphi panel has defined a harmonized protocol (HarP) for the manual segmentation of the hippocampus on MR. The aim of this study is to study the concurrent validity of the HarP toward local protocols, and its major sources of variance.MethodsFourteen tracers segmented 10 Alzheimer's Disease Neuroimaging Initiative (ADNI) cases scanned at 1.5 T and 3T following local protocols, qualified for segmentation based on the HarP through a standard web-platform and resegmented following the HarP. The five most accurate tracers followed the HarP to segment 15 ADNI cases acquired at three time points on both 1.5 T and 3T.ResultsThe agreement among tracers was relatively low…
Increased cortical curvature reflects white matter atrophy in individual patients with early multiple sclerosis
2014
Objective White matter atrophy occurs independently of lesions in multiple sclerosis. In contrast to lesion detection, the quantitative assessment of white matter atrophy in individual patients has been regarded as a major challenge. We therefore tested the hypothesis that white matter atrophy (WMA) is present at the very beginning of multiple sclerosis (MS) and in virtually each individual patient. To find a new sensitive and robust marker for WMA we investigated the relationship between cortical surface area, white matter volume (WMV), and whole-brain-surface-averaged rectified cortical extrinsic curvature. Based on geometrical considerations we hypothesized that cortical curvature increa…
Lymphocytic Mitochondrial Aconitase Activity is Reduced in Alzheimer's Disease and Mild Cognitive Impairment
2015
Background: Specific mechanisms behind the role of oxidative/nitrosative stress and mitochondrial dysfunction in Alzheimer's disease (AD) pathogenesis remain elusive. Mitochondrial aconitase (ACO2) is a Krebs cycle enzyme sensitive to free radicalmediated damage. Objective: We assessed activity and expression of ACO2 extracted from blood lymphocytes of subjects with AD, mild cognitive impairment (MCI), older adults with normal cognition (OCN, age >= 65 years), and younger adults with normal cognition (YCN, age < 65 years). Plasma levels and activities of antioxidants were also measured. Methods: Blood samples were collected from 28 subjects with AD, 22 with MCI, 21 OCN, and 19 YCN. ACO2 act…
Allocortical neurofibrillary changes in progressive supranuclear palsy.
1992
Silver techniques for intraneuronal cytoskeleton abnormalities (neurofibrillary tangles and neuropil threads) and extracellular A4-amyloid deposits were used to examine lesions of the cerebral cortex in six cases of progressive supranuclear palsy (three were mentally unimpaired and three showed moderate degrees of dementia). Deposits of A4-amyloid protein occurred in small numbers or were absent. Neurofibrillary tangles and neuropil threads were present in all cases and were largely confined to the allocortex. A characteristic pattern of changes was found in the entorhinal cortex. The three mentally unimpaired individuals had mild cortical changes virtually confined to the transentorhinal r…
Ultrastructural Hippocampal and White Matter Alterations in Mild Cognitive Impairment: A Diffusion Tensor Imaging Study
2003
Mild cognitive impairment (MCI) is considered to be a transitional stage between normal aging and dementia. In Alzheimer’s disease (AD), white matter structural pathology is due to Wallerian degeneration and central angiopathy. However, in MCI patients, the presence and extent of white matter alterations as a possible correlate of impaired memory function and as predictor of subsequent progression to AD is not clarified yet. Diffusion tensor imaging (DTI) reveals the ultrastructural integrity of cerebral white matter tracts. Therefore, it could detect pathological processes that modify tissue integrity in patients with MCI. In our prospective study, conventional and diffusion tensor MR scan…
Validating the DemTect with 18-Fluoro-2-Deoxy-Glucose Positron Emission Tomography as a Sensitive Neuropsychological Screening Test for Early Alzheim…
2005
<i>Objectives:</i> The first study to validate the diagnostic value of the DemTect, a short neuropsychological screening test for dementia (8–10 min), using 18-fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) in patients of a memory clinic. <i>Methods:</i> DemTect results were compared to the clinical diagnosis and to FDG-PET as a reference method for the early in vivo detection of Alzheimer’s disease (AD). <i>Results:</i> 38 patients (age 65.2 ± 9.8 years, 16 men, 22 women) were investigated using clinical standard examination, FDG-PET, and cranial magnetic resonance imaging. According to NINCDS-ADRDA and Petersen’s criteria, 18 patients had…
Limited agreement between biomarkers of neuronal injury at different stages of Alzheimer's disease
2013
Abstract New diagnostic criteria for Alzheimer's disease (AD) treat different biomarkers of neuronal injury as equivalent. Here, we quantified the degree of agreement between hippocampal volume on structural magnetic resonance imaging, regional glucose metabolism on positron emission tomography, and levels of phosphorylated tau in cerebrospinal fluid (CSF) in 585 subjects from all phases of the AD Neuroimaging Initiative. The overall chance-corrected agreement was poor (Cohen κ, 0.24–0.34), in accord with a high rate of conflicting findings (26%–41%). Neither diagnosis nor APOE e4 status significantly influenced the distribution of agreement between the biomarkers. The degree of agreement t…
Stage-dependent and sector-specific neuronal loss in hippocampus during Alzheimer's disease
2000
Recent stereological studies documented a severe loss of hippocampal neurons in end-stage Alzheimer's disease. The development of the disease, however, is progressive and slow, over clinically inconspicuous decades. The Braak-staging system distinguishes six histopathological stages some of which are not accompanied by clinical symptoms. We analyzed hippocampal cell loss in correlation to Braak stages. Neuron numbers were determined with unbiased stereological principles in a defined subportion of the hippocampus of 28 subjects. There were no age-dependent neuronal losses in any of the hippocampal subdivisions examined. Compared to stage I, pyramidal cell loss in CA1 was reduced by 33% in s…