Diagnostic Utility of Cerebral White Matter Integrity in Early Alzheimer's Disease

David K. Johnson, Willis Barrow, RaeAnn Anderson, Amith Harsha, Robyn Honea, William M. Brooks, Jeffrey M. Burns
2010 International Journal of Neuroscience  
We compared white matter integrity with brain atrophy in healthy controls and participants with very mild dementia (Clinical Dementia Rating 0 vs. 0.5) from the Brain Aging Project, a longitudinal study of aging and memory at the University of Kansas Medical Center. Structural magnetic resonance imaging and diffusion tensor imaging (DTI) including fractional anisotropy and mean diffusivity were performed on 27 patients with very mild dementia (Clinical Dementia Rating = 0.5) of the Alzheimer's
more » ... ype (DAT), and 32 cognitively normal subjects. Patient groups were compared across 6 volumetric measures and 14 DTI regions of interest. Very mildly demented patients showed expected disease-related patterns of brain atrophy with reductions in whole-brain and hippocampal volumes most prominent. DTI indices of white matter integrity were mixed. Right parahippocampus showed significant but small disease-related reductions in fractional anisotropy. Right parahippocampus and left internal capsule showed greater mean diffusivity in early DAT compared with controls. A series of discriminant analyses demonstrated that gray matter atrophy was a significantly better predictor of dementia status than were DTI indices. Brain atrophy was most strongly related to very mild DAT. Modest disease-related white matter anomalies were present in temporal cortex, and deep white matter had limited discriminatory diagnostic power, probably because of the very mild stage of disease in these participants. Keywords Alzheimer's disease; brain atrophy; diffusion tensor imaging (DTI); white matter disease White matter disease (WMD) is seen in neuropathologic examination in over 50% of confirmed cases of Alzheimer's disease (AD). In these moderate-to late-stage dementia of the Alzheimer's type (DAT) individuals, WMD appears global in nature, showing a nonspecific pattern of distribution (Englund & Brun, 1990) . In life, the prevalence of white matter hyperintensities visible by neuroimaging are increased in AD (Scheltens et al., 1992)
doi:10.3109/00207454.2010.494788 pmid:20615058 pmcid:PMC3108435 fatcat:fzqpb7z44jebtbvaphssgn6v7e