Dataset Information

Decreased hippocampal metabolism in high-amyloid mild cognitive impairment.

ABSTRACT:

Introduction

Hippocampal volume (HV), cortical metabolism, and thickness are decreased in mild cognitive impairment (MCI). Hippocampal metabolism (HM) studies comparing MCI and clinically normal (CN) elderly gave inconsistent results. As hippocampus is a key region in Alzheimer's disease, we hypothesized that HM is specifically decreased in high-amyloid MCI.

Methods

Overall, 250 CN and 45 MCI underwent three-dimensional magnetic resonance imaging, fludeoxyglucose-positron emission tomography, and fluorodeoxyglucose-positron emission tomography (PET), and Pittsburgh Compound B (PiB) PET. We investigated the interaction between clinical and amyloid status on HM, HV, cortical metabolism, and thickness using linear models, covarying age, gender, and education. Analyses were conducted with and without correction for multiple comparisons and for partial volume effects.

Results

Volume-adjusted HM was decreased in high-amyloid MCI but close to normal in low-amyloid MCI and in high-amyloid CN. Both MCI groups had hippocampal atrophy, although less severe in low-amyloid MCI. High-amyloid CN and high-amyloid MCI had cortical hypometabolism.

Discussion

HM is decreased when both cognitive impairment and amyloid are present.

SUBMITTER: Hanseeuw BJ

PROVIDER: S-EPMC5148703 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Decreased hippocampal metabolism in high-amyloid mild cognitive impairment.

Hanseeuw Bernard J BJ Schultz Aaron P AP Betensky Rebecca A RA Sperling Reisa A RA Johnson Keith A KA

Alzheimer's & dementia : the journal of the Alzheimer's Association 20160713 12

<h4>Introduction</h4>Hippocampal volume (HV), cortical metabolism, and thickness are decreased in mild cognitive impairment (MCI). Hippocampal metabolism (HM) studies comparing MCI and clinically normal (CN) elderly gave inconsistent results. As hippocampus is a key region in Alzheimer's disease, we hypothesized that HM is specifically decreased in high-amyloid MCI.<h4>Methods</h4>Overall, 250 CN and 45 MCI underwent three-dimensional magnetic resonance imaging, fludeoxyglucose-positron emission ...[more]

PMID: 27421609

Similar Datasets

Project description:BackgroundPrevious publications indicate that Alzheimer's Disease (AD) related cortical atrophy may develop in asymmetric patterns, with accentuation of the left hemisphere. Since fluorodeoxyglucose positron emission tomography (FDG PET) measurements of the regional cerebral metabolic rate of glucose (rCMRgl) provide a sensitive and specific marker of neurodegenerative disease progression, we sought to investigate the longitudinal pattern of rCMRgl in amyloid-positive persons with mild cognitive impairment (MCI) and dementia, hypothesizing asymmetric declines of cerebral glucose metabolism.MethodsUsing florbetapir PET and cerebrospinal fluid (CSF) measures to define amyloid-β (Aβ) positivity, 40 Aβ negative (Aβ-) cognitively unimpaired controls (CU; 76 ± 5y), 76 Aβ positive (Aβ+) persons with MCI (76 ± 7y) and 51 Aβ + persons with probable AD dementia (75 ± 7y) from the AD Neuroimaging Initiative (ADNI) were included in this study with baseline and 2-year follow-up FDG PET scans. The degree of lateralization of longitudinal rCMRgl declines in subjects with Aβ + MCI and AD in comparison with Aβ- CU were statistically quantified via bootstrapped lateralization indices [(LI); range - 1 (right) to 1 (left)].ResultsCompared to Aβ- CU, Aβ + MCI patients showed marked left hemispheric lateralization (LI: 0.78). In contrast, modest right hemispheric lateralization (LI: -0.33) of rCMRgl declines was found in Aβ + persons with probable AD dementia. Additional comparisons of Aβ + groups (i.e. MCI and probable AD dementia) consequently indicated right hemispheric lateralization (LI: -0.79) of stronger rCMRgl declines in dementia stages of AD. For all comparisons, voxel-based analyses confirmed significant (pFWE<0.05) declines of rCMRgl within AD-typical brain regions. Analyses of cognitive data yielded predominant decline of memory functions in both MCI and dementia stages of AD.ConclusionsThese data indicate that in early stages, AD may be characterized by a more lateralized pattern of left hemispheric rCMRgl declines. However, metabolic differences between hemispheres appear to diminish with further progression of the disease.

Project description:Beta-amyloid deposition is one of the earliest pathological markers associated with Alzheimer's disease. Mild cognitive impairment in the setting of beta-amyloid deposition is considered to represent a preclinical manifestation of Alzheimer's disease. In vivo imaging studies are unique in their potential to advance our understanding of the role of beta-amyloid deposition in cognitive deficits in Alzheimer's disease and in mild cognitive impairment. Previous work has shown an association between global cortical measures of beta-amyloid deposition ('amyloid positivity') in mild cognitive impairment with greater cognitive deficits and greater risk of progression to Alzheimer's disease. The focus of the present study was to examine the relationship between the regional distribution of beta-amyloid deposition and specific cognitive deficits in people with mild cognitive impairment and cognitively normal elderly individuals. Forty-seven participants with multi-domain, amnestic mild cognitive impairment (43% female, aged 57-82 years) and 37 healthy, cognitively normal comparison subjects (42% female, aged 55-82 years) underwent clinical and neuropsychological assessments and high-resolution positron emission tomography with the radiotracer 11C-labelled Pittsburgh compound B to measure beta-amyloid deposition. Brain-behaviour partial least-squares analysis was conducted to identify spatial patterns of beta-amyloid deposition that correlated with the performance on neuropsychological assessments. Partial least-squares analysis identified a single significant (P < 0.001) latent variable which accounted for 80% of the covariance between demographic and cognitive measures and beta-amyloid deposition. Performance in immediate verbal recall (R = -0.46 ± 0.07, P < 0.001), delayed verbal recall (R = -0.39 ± 0.09, P < 0.001), immediate visual-spatial recall (R = -0.39 ± 0.08, P < 0.001), delayed visual-spatial recall (R = -0.45 ± 0.08, P < 0.001) and semantic fluency (R = -0.33 ± 0.11, P = 0.002) but not phonemic fluency (R = -0.05 ± 0.12, P < 0.705) negatively covaried with beta-amyloid deposition in the identified regions. Partial least-squares analysis of the same cognitive measures with grey matter volumes showed similar associations in overlapping brain regions. These findings suggest that the regional distribution of beta-amyloid deposition and grey matter volumetric decreases is associated with deficits in executive function and memory in mild cognitive impairment. Longitudinal analysis of these relationships may advance our understanding of the role of beta-amyloid deposition in relation to grey matter volumetric decreases in cognitive decline.

Dataset Information

Decreased hippocampal metabolism in high-amyloid mild cognitive impairment.

Introduction

Methods

Results

Discussion

Publications

Decreased hippocampal metabolism in high-amyloid mild cognitive impairment.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets