White matter hyperintensities influence distal cortical β-amyloid accumulation in default mode network pathways.
Doaa G Ali, Ahmed A Bahrani, Riham H El Khouli, Brian T Gold, Yang Jiang, Valentinos Zachariou, Donna M Wilcock, Gregory A Jicha
Brain and Behavior October 2023 DOI: 10.1002/brb3.3209 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Cross-sectional observational study Longitudinal Peer reviewed |
|---|---|
| Sample size | 72 |
| Population | Clinically unimpaired older adults (Mini-Mental State Examination ≥26, mean age 74.96 years) from the Alzheimer's Disease Neuroimaging Initiative (ADNI3) |
| Measures | regional standardized uptake value ratio (SUVr) from Aβ-PET, white matter hyperintensity (WMH) volumes from three-dimensional MRI FLAIR images |
| Topics | Default mode network |
| Keywords | Neuroimaging Preclinical alzheimer's disease White matter hyperintensities |
| Key findings | Increased white matter hyperintensity volumes in the superior longitudinal fasciculus were associated with increased regional amyloid-beta PET standardized uptake value ratios in the inferior parietal lobule (p = .011). The authors suggest that amyloid-beta in parietal cortex is related to small vessel disease in downstream white matter pathways in preclinical Alzheimer's disease. |
Abstract
Cerebral small vessel disease (SVD) has been suggested to contribute to the pathogenesis of Alzheimer's disease (AD). Yet, the role of SVD in potentially contributing to AD pathology is unclear. The main objective of this study was to test the hypothesis that WMHs influence amyloid β (Aβ) levels within connected default mode network (DMN) tracts and cortical regions in cognitively unimpaired older adults. Regional standard uptake value ratios (SUVr) from Aβ-PET and white matter hyperintensity (WMH) volumes from three-dimensional magnetic resonance imaging FLAIR images were analyzed across a sample of 72 clinically unimpaired (mini-mental state examination ≥26), older adults (mean age 74.96 and standard deviation 8.13) from the Alzheimer's Disease Neuroimaging Initiative (ADNI3). The association of WMH volumes in major fiber tracts projecting from cortical DMN regions and Aβ-PET SUVr in the connected cortical DMN regions was analyzed using linear regression models adjusted for age, sex, ApoE, and total brain volumes. The regression analyses demonstrate that increased WMH volumes in the superior longitudinal fasciculus were associated with increased regional SUVr in the inferior parietal lobule (p = .011). The findings suggest that the relation between Aβ in parietal cortex is associated with SVD in downstream white matter (WM) pathways in preclinical AD. The biological relationships and interplay between Aβ and WM microstructure alterations that precede overt WMH development across the continuum of AD progression warrant further study.
Comparable studies
Other cross-sectional and survey studies on default mode network, most cited first.
Citations in the library
Cites 3
- Resting-State Functional Connectivity Reflects Structural Connectivity in the Default Mode Network Cerebral Cortex April 9, 2008
- Default Mode Network Activity and Connectivity in Psychopathology Annual Review of Clinical Psychology March 29, 2012
- Increased posterior default mode network activity and structural connectivity in young adult APOE-ε4 carriers: a multimodal imaging investigation Neurobiology of Aging September 22, 2018