title: White matter damage in frontotemporal lobar degeneration spectrum.
abstract: White matter (WM) tract damage was assessed in patients with the behavioral variant frontotemporal dementia (bvFTD) and the 3 primary progressive aphasia (PPA) variants and compared with the corresponding brain atrophy patterns. Thirteen bvFTD and 20 PPA patients were studied. Tract-based spatial statistics and voxel-based morphometry were used. Patients with bvFTD showed widespread diffusion tensor magnetic resonance imaging (DT MRI) abnormalities affecting most of the WM bilaterally. In PPA patients, WM damage was more focal and varied across the 3 syndromes: left frontotemporoparietal in nonfluent, left frontotemporal in semantic, and left frontoparietal in logopenic patients. In each syndrome, DT MRI changes extended beyond the topography of gray matter loss. Left uncinate damage was the best predictor of frontotemporal lobar degeneration diagnosis versus controls. DT MRI measures of the anterior corpus callosum and left superior longitudinal fasciculus differentiated bvFTD from nonfluent cases. The best predictors of semantic PPA compared with both bvFTD and nonfluent cases were diffusivity abnormalities of the left uncinate and inferior longitudinal fasciculus. This study provides insights into the similarities and differences of WM damage in bvFTD and PPA variants. DT MRI metrics hold promise to serve as early markers of WM integrity loss that only at a later stage may be detectable by volumetric measures.
authors: Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, 20132 Milan, Italy.
authors: F
authors: F
authors: Agosta
authors: E
authors: E
authors: Scola
authors: E
authors: E
authors: Canu
authors: A
authors: A
authors: Marcone
authors: G
authors: G
authors: Magnani
authors: L
authors: L
authors: Sarro
authors: M
authors: M
authors: Copetti
authors: F
authors: F
authors: Caso
authors: C
authors: C
authors: Cerami
authors: G
authors: G
authors: Comi
authors: S F
authors: SF
authors: Cappa
authors: A
authors: A
authors: Falini
authors: M
authors: M
authors: Filippi
mesh_terms: D000368:Aged; D018888:Aphasia, Primary Progressive / Q000473:pathology*; D001284:Atrophy; D001921:Brain / Q000473:pathology*; D003937:Diagnosis, Differential; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D057174:Frontotemporal Lobar Degeneration / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity