Journal of the International Neuropsychological Society. 2014 Apr;20(4):422-33.
The relative influence of amyloid burden, neuronal structure and function, and prior cognitive performance on prospective memory decline among asymptomatic late middle-aged individuals at risk for Alzheimer’s disease (AD) is currently unknown. We investigated this using longitudinal cognitive data from 122 middle-aged adults (21 “Decliners” and 101 “Stables”) enrolled in the Wisconsin Registry for Alzheimer’s Prevention who underwent multimodality neuroimaging (11C-Pittsburgh Compound B (PiB), 18F-fluorodeoxyglucose (FDG), and structural/functional MRI) 5.7±1.4 years (range=2.9-8.9) after their baseline cognitive assessment. Covariate-adjusted regression analyses revealed that the only imaging measure that significantly distinguished Decliners from Stables (p=.027) was a Neuronal Function composite derived from FDG and fMRI. In contrast, several cognitive measures, especially those that tap episodic memory, significantly distinguished the groups (p’s < .05). Complementary receiver operating characteristic curve analyses identified the Brief Visuospatial Memory Test-Revised (BVMT-R) Total (.82±.05, p<.001), the BVMT-R Delayed Recall (.73±.06, p=.001), and the Reading subtest from the Wide-Range Achievement Test-III (.72±.06, p=.002) as the top three measures that best discriminated the groups. These findings suggest that early memory test performance might serve a more clinically-pivotal role in forecasting future cognitive course than is currently presumed.