A Diffusion Tensor Imaging Study of Cross-Sectional and Longitudinal White Matter Alterations in Frontotemporal Lobar Degeneration

Yu Zhang^1,2, Maria Carmela Tartaglia², Norbert Schuff^1,2, Gloria Chiang^1,2, Christopher Ching^1,2, Howard J. Rosen², Bruce L. Miller², Michael W. Weiner^1,2

Behavioral variant frontotemporal dementia (bvFTD), semantic dementia (SD) and progressive nonfluent aphasia (PNFA) are three major clinical subtypes of frontotemporal lobar degeneration (FTLD). In this study, cross-sectional and a preliminary longitudinal diffusion tensor imaging (DTI) analyses were performed in 12 bvFTD, 6 SD, 6 PNFA, and 19 healthy control (CN) subjects. Cross-sectional analysis revealed bvFTD is associated with a characteristic pattern of fractional anisotropy (FA) reductions in the frontal and temporal regions, SD predominantly affects the uncinate fasciculus, and PNFA affects the left arcuate fasciculus. Preliminary longitudinal analysis suggests that DTI captures disease progression in FTLD.