White Matter Integrity on DTI and the Pathologic Staging of Alzheimer’s Disease

Publication date: Available online 4 May 2017
Source:Neurobiology of Aging
Author(s): Kejal Kantarci, Melissa E. Murray, Christopher G. Schwarz, Robert Reid, Scott A. Przybelski, Timothy Lesnick, Samantha M. Zuk, Mekala R. Raman, Matthew L. Senjem, Jeffrey L. Gunter, Bradley F. Boeve, David S. Knopman, Joseph E. Parisi, Ronald C. Petersen, Clifford R. Jack, Dennis Dickson
Pattern of diffusion tensor MRI (DTI) alterations were investigated in pathologically-staged Alzheimer's disease (AD) patients (n=46). Patients with antemortem DTI studies and a range of AD pathology at autopsy were included. Patients with a high neurofibrillary tangle (NFT) stage (Braak IV-VI) had significantly elevated mean diffusivity (MD) in the crus of fornix and ventral cingulum tracts, precuneus, and entorhinal white matter on voxel-based analysis after adjusting for age and time from MRI to death (p<0.001). Higher MD and lower fractional anisotropy (FA) in the ventral cingulum tract, entorhinal and precuneus white matter was associated with higher Braak NFT stage and clinical disease severity. There were no MD and FA differences among the low (none and sparse) and high (moderate and frequent) β-amyloid neuritic plaque groups. The NFT pathology of AD is associated with DTI alterations involving the medial temporal limbic connections and medial parietal white matter. This pattern of diffusion abnormalities is also associated with clinical disease severity.



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