Arachnoid granulation morphologies and β-amyloid and tau pathology in older adults.

INTRODUCTION

Arachnoid granulations (AG) prominently enlarge with age, yet limited studies evaluate AG in neurodegeneration. Here, we investigate the associations of AG morphologies with Alzheimer's disease (AD).

METHODS

Macroscopic AG properties were evaluated along dorsal post mortem brain specimens (n = 882). Regression models were used to analyze their associations with AD neuropathology and dementia, adjusting for demographics.

RESULTS

Participants died at mean age of 90.62 (SD = 6.98) years. β-amyloid (odds ratio [OR], 0.79 [95% confidence interval {CI}, 0.66-0.95]) and neurofibrillary tangles (OR, 0.84 [95% CI, 0.71-0.98]) inversely associated with AG count. 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 AG patch count. Linear type AG in frontal (OR, 1.46 [95% CI, 1.03-2.07]) and parietal (OR, 1.57 [95% CI, 1.02-2.43]) regions was associated with higher odds of dementia.

DISCUSSION: Select AG morphologic properties associate with AD outcomes. Future studies should explore mechanisms underlying these associations.