Quantification of small vessel disease in frontal and parietal white matter, genu and splenium

Background Cerebral small vessel disease (SVD) encompasses progressive fibrosis/hyalinosis of the small arteries (lipohyalinosis) and arterioles (arteriolosclerosis) of the white matter (WM) resulting in ischemic WM damage. SVD is commonly assessed using a broad semi‐quantitative (SQ) criterion. We implemented sclerotic index (SI) assessment to quantitatively assess vessel wall thickness in small arteries and arterioles separately in four regions known to exhibit WM changes. Method The cohort consisted of 75 cases from the University of California Davis Alzheimer’s Disease Centre Biorepository, neuropathological diagnosed as controls (n=18), intermediate Alzheimer’s disease neuropathologic change (n=13), definite Alzheimer’s disease (n=33), or cerebrovascular disease (n=11). H&E sections that included frontal and parietal WM, genu, or splenium were SQ assessed for SVD and images of small arteries (150‐800μm diameter) and arterioles (40‐150μm diameter) were captured. SI assessment was performed, and mean SI scores were calculated for arteries, arterioles, and an overall total. Result Age was not associated with any SQ or SI measure in any region (p>0.106). SI and SQ scores of both arteries and arterioles were highly correlated in all regions (rho >0.551, p