Morphological and Structural Network Analysis of Sporadic Alzheimer’s Disease Brains Based on the APOE4 Gene

Abstract

Background: Alzheimer’s disease (AD) is an increasingly common type of dementia. Apolipoprotein E (APOE) gene is a strong risk factor for AD. Objective: Here, we explored alterations in grey matter structure (GMV) and networks in AD, as well as the effects of the APOE ɛ4 allele on neuroimaging regions based on structural magnetic resonance imaging (sMRI). Methods: All subjects underwent an sMRI scan. GMV and cortical thickness were calculated using voxel-based morphological analysis, and structural networks were constructed based on graph theory analysis to compare differences between AD and normal controls. Results: The volumes of grey matter in the bilateral inferior temporal gyrus, right middle temporal gyrus, right inferior parietal lobule, right limbic lobe, right frontal lobe, left anterior cingulate gyrus, and bilateral olfactory cortex of patients with AD were significantly decreased. The cortical thickness in patients with AD was significantly reduced in the left lateral occipital lobe, inferior parietal lobe, orbitofrontal region, precuneus, superior parietal gyrus, right precentral gyrus, middle temporal gyrus, pars opercularis gyrus, insular gyrus, superior marginal gyrus, bilateral fusiform gyrus, and superior frontal gyrus. In terms of local properties, there were significant differences between the AD and control groups in these areas, including the right bank, right temporalis pole, bilateral middle temporal gyrus, right transverse temporal gyrus, left postcentral gyrus, and left parahippocampal gyrus. Conclusion: There were significant differences in the morphological and structural covariate networks between AD patients and healthy controls under APOE ɛ4 allele effects.