Subregions of the inferior parietal lobule are associated with progression to Alzheimer's disease in participants of the Alzheimer's Disease Neuroimaging Initiative

Abstract

Several regions within the brain have been associated with progression from normal to Alzheimer's disease (AD) based on magnetic resonance imaging (MRI) studies, including the hippocampus, entorhinal cortex, and more recently, the inferior parietal lobule (IPL). In this study, the IPL was divided into three regions: the gyrus (G‐IPL), the banks of the sulcus (B‐IPL), and the fundus (F‐IPL) to determine if these regions were associated with the progression from normal to AD. Participants of the ADNI (n=12, 50% male, average age 78) underwent a structural MRI scan and neuropsychological exam (NP), and were categorized as normal controls, mild cognitively impaired (MCI), or AD. FreeSurfer was used to measure these regions. Once scans were processed, each IPL region was manually traced based on automated curvature intensities and corrected for head size. Multivariate analysis of variance determined that the B‐IPL was different among groups (p<0.05) in the right (RH) and left (LH) hemisphere, and G‐IPL was different in the LH. Correlations between these regions and NP scores were as follows (p<0.05): LH B‐IPL with Auditory Verbal Learning immediate and delayed, and both LH and RH G‐IPL with the categories test. These findings suggest that the banks and gyral portions of the IPL are impacted by AD pathology before the fundus of the IPL in individuals with MCI and AD.Grant Funding SourceNone