Document Type

Conference Proceeding

Language

eng

Format of Original

1 p.

Publication Date

2012

Publisher

MIT Press

Source Publication

Journal of Cognitive Neuroscience

Source ISSN

0898-929X

Abstract

The apolipoprotein ε4 allele is a risk factor for Alzheimer's disease. ε4 carriers diagnosed with AD or MCI exhibit an increased rate of atrophy on MRI relative to non-carriers. Few longitudinal studies have examined the rate of atrophy and cognitive change in older ε4 carriers who were cognitively intact at study entry. In this study, structural MRI and episodic memory testing were administered on two occasions separated by 5 years to 45 cognitively intact older adults, ages 65-90 years, divided into two groups: (1) carriers with one or both ε4 alleles (n=24) and (2) demographically-matched non-carriers (n=21). Longitudinal analysis of whole brain gray matter, whole brain white matter, and hippocampal volumes were derived from Freesurfer software. Analysis of variance indicated a significant group x time interaction for both left and right cortical gray matter (p's < .05; 2% decrease) and left hippocampus (p < .001; 5.6% decrease); right hippocampus showed a marginal effect (p=.086; 4.9% decrease). In all instances, the ε4 group showed greater atrophy over the five-year interval than non-carriers. White matter brain volume significantly decreased over retest intervals (3.5%), but did not differ between groups. Over the same retest interval, the ε4 group also showed significantly greater decline than non-carriers on delayed word recall and percent retention on a list-learning task. These data suggest that the presence of an ε4 allele carries an increased risk for cortical gray matter and hippocampal atrophy and memory loss among older participants who were cognitively intact at study entry.

Comments

Published version. Published as part of the proceedings of the conference, 2012 Cognitive Neuroscience Society Annual Meeting, 2012: 149. Publisher Link. © 2012 Massachusetts Institute of Technology (MIT Press). Used with permission.

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