title: Isolated U-fiber involvement in MS: preliminary observations.
abstract: We studied the frequency and location of isolated U-fiber involvement in MS and correlated these findings exploratively with physical disability and neuropsychological impairment. Fifty-three MS patients were examined. Three-millimeter-thick, fast spin-echo T2-weighted MR images and spin-echo postgadolinium T1-weighted images were obtained. Computer software that which had been validated previously for quantitation of MS lesions was used to detect lesions on the T2-weighted images. The Expanded Disability Status Scale (EDSS), Ambulation Index (AI), and a battery of neurocognitive tests were performed on each patient. Forty-two arcuate hyperintensities along the U-fiber were detected by the software in 28 patients (53%). Twenty-seven lesions (64.3%) were seen in the frontal lobe, eight (19.0%) in the temporal lobe, three (7.1%) in the parietal lobe, three (7.1%) in the occipital lobe, and one (2.4%) in both frontal and parietal lobes. Four lesions (9.5%) showed gadolinium enhancement. Seventeen lesions (40%) were hypointense on the T1-weighted images. Scores of three of the 11 neuropsychological tests reflecting performance in executive control and memory were significantly different at least at the p = 0.05 level between the eight patients with multiple, isolated U-fiber lesions and the 45 patients without any or with only a single U-fiber lesion. No significant difference was noted for EDSS or AI. Isolated U-fiber involvement is an underappreciated MR finding in MS. Our preliminary hypothesis is that U-fiber lesions may contribute to neuropsychological impairment, although our observation requires confirmation.
authors.affiliation: Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia 19104-4283, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Miki
authors.forename: R I
authors.initials: RI
authors.lastname: Grossman
authors.forename: J K
authors.initials: JK
authors.lastname: Udupa
authors.forename: L
authors.initials: L
authors.lastname: Wei
authors.forename: D L
authors.initials: DL
authors.lastname: Kolson
authors.forename: L J
authors.initials: LJ
authors.lastname: Mannon
authors.forename: M
authors.initials: M
authors.lastname: Grossman
mesh_terms: D000328:Adult; D003072:Cognition Disorders / Q000503:physiopathology*; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000503:physiopathology* / Q000523:psychology; D009412:Nerve Fibers / Q000502:physiology*; D009483:Neuropsychological Tests; D012984:Software