Regional amyloid accumulation predicts memory decline in initially cognitively unimpaired individuals

Introduction The value of quantitative longitudinal and regional amyloid beta (A beta) measurements in predicting cognitive decline in initially cognitively unimpaired (CU) individuals remains to be determined. Methods We selected 133 CU individuals with two or more [C-11]Pittsburgh compound B ([C-11]PiB) scans and neuropsychological data from Open Access Series of Imaging Studies (OASIS-3). Baseline and annualized distribution volume ratios were computed for a global composite and four regional clusters. The predictive value of A beta measurements (baseline, slope, and interaction) on longitudinal cognitive performance was examined. Results Global performance could only be predicted by A beta burden in an early cluster (precuneus, lateral orbitofrontal, and insula) and the precuneus region of interest (ROI) by itself significantly improved the model. Precuneal A beta burden was also predictive of immediate and delayed episodic memory performance. In A beta subjects at baseline (N = 93), lateral orbitofrontal A beta burden predicted working and semantic memory performance. Discussion Quantifying longitudinal and regional changes in A beta can improve the prediction of cognitive functioning in initially CU individuals.