title: Abnormal cervical cord function contributes to fatigue in multiple sclerosis.
abstract: BACKGROUND/OBJECTIVE  We aimed to investigate whether cervical cord damage and dysfunction is associated with the presence and severity of fatigue in multiple sclerosis (MS) using a multiparametric magnetic resonance (MR) approach.
  
  
  METHODS
  Cervical cord functional magnetic resonance imaging (fMRI) during a tactile stimulation of the right hand, and structural brain and cord MRI were acquired from 20 controls, 15 MS patients without fatigue (NF) and 20 MS patients with fatigue (F). Between-group differences in the extent of focal lesions and diffusivity abnormalities in the brain and cord, cord-normalized cross-sectional area (CSAn) and fMRI activity were assessed.
  
  
  RESULTS
  All structural MRI measures differed significantly among groups, except for cord lesion number and CSAn. Compared with controls, NF-MS patients experienced higher cord recruitment (p=0.04). Compared with F-MS, NF-MS patients had a lower brain normal-appearing white matter average fractional anisotropy (p=0.001) and increased cord recruitment (p=0.02). In patients with MS, the extent of cord recruitment was correlated with the severity of fatigue (r=-0.34, p=0.04). Compared with the other two groups, F-MS patients had a more diffuse recruitment of cord quadrants on the axial and longitudinal planes.
  
  
  CONCLUSIONS
  Abnormalities of function, but not of structure, of the cervical cord are likely to contribute to the pathogenesis of fatigue in MS.
authors.affiliation: Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: M A
authors.initials: MA
authors.lastname: Rocca
authors.forename: M
authors.initials: M
authors.lastname: Absinta
authors.forename: P
authors.initials: P
authors.lastname: Valsasina
authors.forename: M
authors.initials: M
authors.lastname: Copetti
authors.forename: D
authors.initials: D
authors.lastname: Caputo
authors.forename: G
authors.initials: G
authors.lastname: Comi
authors.forename: M
authors.initials: M
authors.lastname: Filippi
mesh_terms: D000328:Adult; D000368:Aged; D001284:Atrophy; D001921:Brain / Q000473:pathology / Q000503:physiopathology; D016022:Case-Control Studies; D002574:Cervical Vertebrae; D016009:Chi-Square Distribution; D004185:Disability Evaluation; D005221:Fatigue / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D016017:Odds Ratio; D011237:Predictive Value of Tests; D012307:Risk Factors; D012720:Severity of Illness Index; D013116:Spinal Cord / Q000473:pathology / Q000503:physiopathology*; D014110:Touch