Abstract
INTRODUCTION: Tau pathology, a hallmark of Alzheimer's disease, is observed in the brains of virtually all individuals over 70 years. METHODS: Using (18)F-AV-1451 ((18)F-flortaucipir) positron emission tomography, we evaluated tau pathology in 54 cognitively normal participants (mean age: 77.5 years, SD: 8.9) from the Baltimore Longitudinal Study of Aging. We assessed associations between positron emission tomography signal and age, sex, race, and amyloid positivity. We investigated relationships between regional signal and retrospective rates of change in regional volumes and cognitive function adjusting for age, sex, and amyloid status. RESULTS: Greater age, male sex, black race, and amyloid positivity were associated with higher (18)F-AV-1451 retention in distinct brain regions. Retention in the entorhinal cortex was associated with lower entorhinal volume (β = -1.124, SE = 0.485, P = .025) and a steeper decline in memory performance (β = -0.086, SE = 0.039, P = .029). DISCUSSION: Assessment of medial temporal tau pathology will provide insights into early structural brain changes associated with later cognitive impairment and Alzheimer's disease.