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Windham, B. G.

Publications and source records attributed to Windham, B. G..

2 recordsLinked to original sources

Spatial Patterns of White Matter Hyperintensities and Cognitive Function in Older Adults: A Community-Based Study

Abstract Objectives White matter hyperintensities (WMH) are associated with cognitive decline in older adults. We examined whether anatomically defined spatial WMH patterns are associated with cognitive performance and subsequent decline in a large community-based cohort with approximately six years of follow-up. Methods We analyzed 1,667 participants (mean age 76 years) from the Atherosclerosis Risk in Communities Neurocognitive Study. WMH were segmented from FLAIR images and mapped to 112 white matter regions using deep-learning-based parcellation. Principal component analysis identified dominant WMH distribution patterns; candidate components were selected by Horn's parallel analysis and retained if stable across resampled split samples. Linear mixed-effects models examined associations between WMH patterns and cognitive performance at baseline and follow-up, adjusting for demographic, genomic, and vascular risk factors. Robustness was assessed using analyses accounting for total WMH burden, study center, and selective attrition. Results Of 14 candidate principal components (PCs) identified by parallel analysis, eight met the resampling stability criterion and were retained, together explaining 42% of the variance. Three components were associated with cross-sectional or future cognition. PC3, characterized by deep white matter burden in the corpus callosum and anterior corona radiata with relative preservation of superficial white matter, showed no cross-sectional association at baseline but was associated with accelerated decline across multiple domains. Interpretation A deep spatial pattern of WMH loading on the corpus callosum and anterior corona radiata was associated with subsequent cognitive decline in the absence of a cross-sectional association at baseline, independent of total lesion burden.

neuroscience↗

Diffusion MRI based biomarkers reveal a Prolonged Pre Lesional Phase of Cerebral Small Vessel Disease

BackgroundWhite matter hyperintensities (WMH) are widely used to assess cerebral small vessel disease (SVD) but reflect late-stage injury. Diffusion MRI based biomarkers have been proposed to capture earlier SVD-related microstructural damage but their temporal progression relative to WMH and the risk factors associated with this progression have not been explored. MethodsWe analyzed longitudinal neuroimaging data from 2,047 participants from a population-based cohort study (aged 49-101 years, 47% female). Using multi-output nonlinear mixed-effects models, we characterized the temporal progression of WMH and four diffusion MRI based biomarkers: fractional anisotropy of the genu of the corpus callosum (Genu-FA), peak width of skeletonized mean diffusivity (PSMD), free water (FW), and Arteriolosclerosis-score (ARTS). Models incorporated participant-specific time shifts, correlations between biomarkers, and effects of risk factors (sex, education, APOE {varepsilon}4 status, and cardiometabolic conditions). ResultsARTS, Genu-FA, FW, and PSMD became abnormal in 50% of the study population 16, 12, 10, and 7 years before WMH, respectively. Global markers (ARTS, FW, PSMD, WMH) were correlated, indicating shared substrates of widespread white matter injury. Genu-FA, a vascular risk microstructural injury biomarker, was weakly coupled with WMH and had an earlier but more linear worsening across adulthood. Cardiometabolic conditions predicted earlier worsening of all biomarkers. Females showed earlier WMH, Genu-FA, and ARTS abnormalities whereas males exhibited earlier PSMD and FW abnormalities. ConclusionsDiffusion MRI based biomarkers capture microstructural injury at least a decade before appearance of WMH, revealing a prolonged phase of early SVD and highlighting their potential for SVD prevention.

neuroscience↗