Diffusion Tensor Imaging Predictors of Episodic Memory Decline in Healthy Elders at Genetic Risk for Alzheimer's Disease. J Int Neuropsychol Soc 2016 Nov;22(10):1005-1015
Date
12/03/2016Pubmed ID
27903333Pubmed Central ID
PMC5916766DOI
10.1017/S1355617716000904Scopus ID
2-s2.0-85001052362 (requires institutional sign-in at Scopus site) 20 CitationsAbstract
OBJECTIVES: White matter (WM) integrity within the mesial temporal lobe (MTL) is important for episodic memory (EM) functioning. The current study investigated the ability of diffusion tensor imaging (DTI) in MTL WM tracts to predict 3-year changes in EM performance in healthy elders at disproportionately higher genetic risk for Alzheimer's disease (AD).
METHODS: Fifty-one cognitively intact elders (52% with family history (FH) of dementia and 33% possessing an Apolipoprotein E ε4 allelle) were administered the Rey Auditory Verbal Learning Test (RAVLT) at study entry and at 3-year follow-up. DTI scanning, conducted at study entry, examined fractional anisotropy and mean, radial and axial diffusion within three MTL WM tracts: uncinate fasciculus (UNC), cingulate-hippocampal (CHG), and fornix-stria terminalis (FxS). Correlations were performed between residualized change scores computed from RAVLT trials 1-5, immediate recall, and delayed recall scores and baseline DTI measures; MTL gray matter (GM) and WM volumes; demographics; and AD genetic and metabolic risk factors.
RESULTS: Higher MTL mean and axial diffusivity at baseline significantly predicted 3-year changes in EM, whereas baseline MTL GM and WM volumes, FH, and metabolic risk factors did not. Both ε4 status and DTI correlated with change in immediate recall.
CONCLUSIONS: Longitudinal EM changes in cognitively intact, healthy elders can be predicted by disruption of the MTL WM microstructure. These results are derived from a sample with a disproportionately higher genetic risk for AD, suggesting that the observed WM disruption in MTL pathways may be related to early neuropathological changes associated with the preclinical stage of AD. (JINS, 2016, 22, 1005-1015).
Author List
Lancaster MA, Seidenberg M, Smith JC, Nielson KA, Woodard JL, Durgerian S, Rao SMAuthors
Melissa A. Lancaster PhD Assistant Professor in the Neurology department at Medical College of WisconsinKristy Nielson PhD Professor in the Psychology department at Marquette University
MESH terms used to index this publication - Major topics in bold
AftercareAged
Aged, 80 and over
Aging
Alzheimer Disease
Apolipoprotein E4
Diffusion Tensor Imaging
Female
Humans
Male
Memory, Episodic
Prognosis
Risk
Temporal Lobe
White Matter
