title: Decreased corticospinal tract fractional anisotropy predicts long-term motor outcome after stroke.
abstract: OBJECTIVE
  Nearly 50% of patients have residual motor deficits after stroke, and long-term motor outcome is difficult to predict. We assessed the predictive value of axonal damage to the corticospinal tract indexed by diffusion tensor imaging fractional anisotropy for long-term motor outcome.
  
  
  METHODS
  Consecutive patients with middle cerebral artery stroke underwent multimodal MRI, including diffusion tensor imaging ≤12 hours, 3 days, and 30 days after onset. Clinical severity, infarct volume, location of corticospinal tract damage on diffusion tensor tractography, and ratios of fractional anisotropy (rFA) between affected and unaffected sides of the corticospinal tract at the pons were evaluated. Severity of motor deficit at 2 years was categorized using the Motricity Index as no deficit (Motricity Index, 100), slight-moderate deficit (Motricity Index, 99-50), or severe deficit (Motricity Index, <50).
  
  
  RESULTS
  We evaluated 70 patients (28 women; 72±12 years). rFA values at day 30 correlated with the degree of motor deficit at 2 years (P<0.001). rFA at day 30 was the only independent predictor of long-term motor outcome (odds ratio, 1.60; 95% confidence interval, 1.26-2.03; P<0.001). The sensitivity, specificity, and positive and negative predictive values of the cutoffs rFA<0.982 for predicting slight-moderate deficit and rFA<0.689 for severe deficit were 94.4%, 84.6%, 73.9%, and 97.1%, respectively, and 100%, 83.3%, 81.3%, and 100%, respectively.
  
  
  CONCLUSIONS
  rFA at day 30 is an independent predictor of long-term motor outcome after stroke.
authors: Department of Radiology (IDI), Girona Biomedical Research Institute (IDIBGI), Hospital Universitari Dr Josep Trueta, Girona, Spain. jpuigalcantara@idibgi.org
authors: Josep
authors: J
authors: Puig
authors: Gerard
authors: G
authors: Blasco
authors: Josep
authors: J
authors: Daunis-I-Estadella
authors: Götz
authors: G
authors: Thomalla
authors: Mar
authors: M
authors: Castellanos
authors: Jaume
authors: J
authors: Figueras
authors: Sebastián
authors: S
authors: Remollo
authors: Cecile
authors: C
authors: van Eendenburg
authors: Javier
authors: J
authors: Sánchez-González
authors: Joaquín
authors: J
authors: Serena
authors: Salvador
authors: S
authors: Pedraza
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016880:Anisotropy; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D009069:Movement Disorders / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D011237:Predictive Value of Tests; D011712:Pyramidal Tracts / Q000503:physiopathology*; D012720:Severity of Illness Index; D013118:Spinal Cord Diseases / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome
keywords: cerebral ischemia; diffusion tensor imaging; fractional anisotropy