Arachnoid Granulation Morphologies Associate with β-Amyloid and Tau Pathology in Older Adults.

INTRODUCTION: Arachnoid granulations (AG) enlarge with age, yet limited studies evaluate AG in neurodegeneration. Here, we investigate associations of AG morphology with Alzheimer's disease (AD) pathology. METHODS: Macroscopic AG properties were systematically evaluated along dorsal postmortem brain specimens from older adults (n=882). Regression models were used to analyze their associations with AD neuropathologic indices, controlling for demographic factors. RESULTS: Participants died at mean age of 90.62 (SD=6.98) years. β-amyloid (Odds ratio/OR, 0.79 [95% CI, 0.66-0.95]) and neurofibrillary tangles (OR, 0.84 [95% CI, 0.71-0.98]) inversely associated with global AG count. Similarly, β-amyloid (OR, 0.78 [95% CI, 0.65-0.92]) and B (Braak) score (OR, 0.80 [95% CI, 0.66-0.96]) inversely associated with global AG patch count. DISCUSSION: β-amyloid and tau pathology are associated with AG morphologies. Future studies should explore the mechanisms underlying these associations across disease stage and demographic factors.