title: Diffuse and focal corticospinal tract disease and its impact on patient disability in multiple sclerosis.
abstract: OBJECTIVE
  We investigated the impact of focal and diffuse corticospinal tracts damage on sensory-motor disability in multiple sclerosis (MS) patients.
  
  
  METHODS
  Twenty-five MS patients underwent 3.0 Tesla (3T) magnetic resonance imaging with diffusion tensor imaging (DTI). The Expanded Disability Status Scale (EDSS) and the Timed 25-Foot Walk test (T25FW) quantified patient physical disability. Fractional anisotropy (FA) and mean diffusivity (MD) of the corticospinal tracts, whole brain and corticospinal tracts lesion volume were also computed. Spearman rank correlation analyses measured the associations between DTI-derived metrics and other measures of disease. Partial correlation analyses between DTI and disability measures were performed and corrected for lesion volumes as appropriate.
  
  
  RESULTS
  Significant associations were seen between FA of the corticospinal tracts and EDSS (r = -.500, P = .0011), motor-EDSS (r = -.519, P = .008), and T25WF (r = -.637, P = .001) scores and MD of the corticospinal tracts and motor-EDSS (r = .469, P = .018) and T25WF (r = .428, P = .033) scores. When correcting for lesion volumes, only the association between FA of the corticospinal tracts and EDSS (r ≤ -.516, p ≤ .01) or motor-EDSS score (r ≤ -.516, p ≤ .01) persisted.
  
  
  CONCLUSIONS
  DTI at 3T shows that the impact of diffuse corticospinal tracts disease on sensory-motor disability is greatly mediated by focal lesions in MS.
authors.affiliation: Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke (NINDS), National Institute of Health (NIH), Bethesda, MD.|D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil.|Institute of Biomedical Sciences and National Center of Structural Biology and Bioimaging (CENABIO), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Tovar-Moll
authors.affiliation: Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke (NINDS), National Institute of Health (NIH), Bethesda, MD.
authors.forename: Iordanis E
authors.initials: IE
authors.lastname: Evangelou
authors.affiliation: Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke (NINDS), National Institute of Health (NIH), Bethesda, MD.
authors.forename: Annie W
authors.initials: AW
authors.lastname: Chiu
authors.affiliation: Office of the Clinical Director, NINDS, NIH, Bethesda, MD.
authors.forename: Sungyoung
authors.initials: S
authors.lastname: Auh
authors.affiliation: Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke (NINDS), National Institute of Health (NIH), Bethesda, MD.
authors.forename: Christina
authors.initials: C
authors.lastname: Chen
authors.affiliation: Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke (NINDS), National Institute of Health (NIH), Bethesda, MD.
authors.forename: Mary
authors.initials: M
authors.lastname: Ehrmantraut
authors.affiliation: Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke (NINDS), National Institute of Health (NIH), Bethesda, MD.
authors.forename: Joan M
authors.initials: JM
authors.lastname: Ohayon
authors.affiliation: Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke (NINDS), National Institute of Health (NIH), Bethesda, MD.
authors.forename: Nancy
authors.initials: N
authors.lastname: Richert
authors.affiliation: Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke (NINDS), National Institute of Health (NIH), Bethesda, MD.
authors.forename: Francesca
authors.initials: F
authors.lastname: Bagnato
mesh_terms: D000328:Adult; D056324:Diffusion Tensor Imaging / Q000379:methods*; D004185:Disability Evaluation; D005260:Female; D020233:Gait Disorders, Neurologic / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications / Q000473:pathology*; D011712:Pyramidal Tracts; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013118:Spinal Cord Diseases / Q000150:complications / Q000473:pathology*
keywords: Multiple sclerosis; black holes; diffusion tensor imaging; white matter damage