Apolipoprotein E epsilon 4 allele is associated with increased atrophy in progressive mild cognitive impairment: A vaxel-based morphometric study

Background. The apolipoprotein E (APOE) epsilon 4 allele is a risk factor for Alzheimer's disease. Earlier studies have shown differences in brain structure according to the APOE 64 status. Objective: To assess possible differences in brain structure according to the APOE epsilon 4 status in mild cognitive impairment (MCI) subjects in relation to conversion to dementia. Methods: In a follow-up study of 56 MCI subjects, 13 MCI subjects progressed to dementia (PMCI) during a mean follow-up time of 31 months. Brain structure differences in both stable MCI (SMCI) and PMCl epsilon 4 carriers and noncarriers in the baseline MRI scan were assessed with voxel-based morphometry. Results: The SMCI epsilon 4 carriers had atrophy in the amygdala and hippocampus compared to the SMCI noncarriers. The PMCl epsilon 4 carriers revealed atrophy of the left inferior frontal gyrus and parietal cortex compared to the PMCI noncarriers. Conclusion: The rate of brain atrophy in certain brain areas may be increased in epsilon 4-positive MCI subjects progressing to dementia. Copyright (c) 2008 S. Karger AG, Basel.