White Matter Hyperintensities and Changes in White Matter Integrity in Patients with Alzheimer’s Disease

• Type of Material: Article
• Authors: Liya Wang, Emory University; Felicia Goldstein, Emory University; Allan I Levey, Emory University; James J Lah, Emory University; Carolyn Meltzer, Emory University; Chad A Holder, Emory University; Hui Mao, Emory University
• Language: English
• Date: 2012-04-22
• Publisher: Springer Verlag (Germany)
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © Springer-Verlag 2010
• Final Published Version (URL): http://www.springerlink.com/content/21lpv07ll5912725/
• Title of Journal or Parent Work: Neuroradiology
• ISSN: 0028-3940
• Volume: 53
• Issue: 5
• Start Page: 373
• End Page: 381
• Grant/Funding Information: This study was supported in part by a grant from NIH (R21AG027335 to HM) and a pilot project grant from The Emory Alzheimer’s Disease Research Center (NIH-NIA P50 AG025688 to HM).
• Keywords: Magnetic Resonance Imaging; Diffusivity; White Matter Hyperintensity; Diffusion Tensor; Alzheimer’s Disease; White Matter
• Research Categories: Health Sciences, Radiology

Abstract

Purpose White matter hyperintensities (WMHs) are a risk factor for Alzheimer’s disease (AD). This study investigated the relationship between WMHs and white matter changes in AD using diffusion tensor imaging (DTI) and the sensitivity of each DTI index in distinguishing AD with WMHs. Subjects and Methods Forty-four subjects with WMHs were included. Subjects were classified into three groups based on the Scheltens rating scale: 15 AD patients with mild WMHs, 12 AD patients with severe WMHs, and 17 controls with mild WMHs. Fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (DR) and axial diffusivity (DA) were analyzed using the region of interest and Tract-Based Spatial Statistics methods. Sensitivity and specificity of DTI indices in distinguishing AD groups from the controls were evaluated. Results AD patients with mild WMHs exhibited differences from control subjects in most DTI indices in the medial temporal and frontal areas; however, differences in DTI indices from AD patients with mild WMHs and AD patients with severe WMHs were found in the parietal and occipital areas. FA and DR were more sensitive measurements than MD and DA in differentiating AD patients from controls, while MD was a more sensitive measurement in distinguishing AD patients with severe WMHs from those with mild WMHs. Conclusions WMHs may contribute to the white matter changes in AD brains, specifically in temporal and frontal areas. Changes in parietal and occipital lobes may be related to the severity of WMHs. DR may serve as an imaging marker of myelin deficits associated with AD.