A Pilot Study for Investigating Differences between Alzheimer’s Patients with and without Significant Vascular Pathology

Abstract

Distinguishing Alzheimer’s disease (AD) from mixed Alzheimer’s and vascular dementia (VD) is a challenging task. In this study, we explored the differences between AD patients and a group with a mixed pathology of AD with cerebrovascular disease (CVD) by analyzing the volumes of several brain regions vulnerable to AD and evidenced by white matter hyper-intensities (WMHs). Moreover, we investigated the correlation between brain volumes and the Alzheimer’s Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) scores of the AD and AD-CVD groups. We collected T1-weighted Magneti-zation Prepared Acquisition with Gradient Echo (MPRAGE) MRI scans from 9 AD participants and 8 AD-CVD participants. Then, we performed the region of interest (ROI) analysis over the MRI data to measure the gray matter (GM) volume of the hippocampus, frontal gyrus, and precuneus as well as the cerebrospinal fluid (CSF) volume of ventricles. Also, we calculated the volume of white matter hyper-intensities (WMHs) of the whole brain and of the frontal-temporal (FT) area. The results did not show any correlation between the baseline ADAS-Cog scores of AD participants and their volumes of above-affected areas and WMHs, while in the AD-CVD group, the CSF volume in ventricles showed a high correlation with ADAS-Cog scores (Spearman’s ρ = 0.714). We did not observe any statistically significant difference in these volumes between AD patients and AD-CVD group.