Andreana Benitez1,
Els Fieremans2, Jens H. Jensen1, Maria F. Falangola1,
Ali Tabesh1, Rachael L. Deardorff1, James S. Babb2,
Dmitry S. Novikov2, Joseph A. Helpern1
1Center
for Biomedical Imaging, Department of Radiology and Radiological Science,
Medical University of South Carolina, Charleston, SC, United States; 2Center
for Biomedical Imaging, Department of Radiology, New York University, New
York, United States
We applied DKI-based white matter tract integrity metrics to the study of Alzheimers disease within the framework of retrogenesis; late-myelinating (LM) tracts are more susceptible to aging and AD, and are therefore hypothesized to decline more so than early-myelinating (EM) tracts, which remain comparatively stable. In our sample (N=41) of matched normal controls, amnestic mild cognitive impairment, and AD subjects, using atlas-based ROI analyses we found that in the course of AD, axonal density loss and myelin breakdown occur in LM tracts, but largely not in EM tracts, and that myelin breakdown in LM tracts correlates with poorer verbal fluency.