title: Detection and Predictive Value of Fractional Anisotropy Changes of the Corticospinal Tract in the Acute Phase of a Stroke.
abstract: A decrease in fractional anisotropy (FA) of the ipsilesional corticospinal tract (CST) distal to stroke lesions in the subacute (eg, 30 days) and chronic phase has been correlated with poor motor outcomes, but it is unclear whether FA values obtained within the acute stroke phase (here defined as 80 hours after onset) can predict later outcome.
  
  
  
  Fifty-eight patients underwent an assessment of motor impairment in the acute phase and at 3 months using the upper extremity Fugl-Meyer assessment. FA values, obtained within 80 hours after stroke onset, were determined in 2 regions of interest: cerebral peduncle and a stretch of the CST caudal to each stroke lesion (nearest-5-slices).
  
  
  
  The FA laterality index for the cerebral peduncle-regions of interest was a poor predictor of 3-month outcome (R(2)=0.044; P=0.137), whereas the slope over the FA laterality index of the nearest-5-slices showed a relatively weak but significant prediction (R(2)=0.11; P=0.022) with the affected side having lower FA values. Initial upper extremity Fugl-Meyer (R(2)=0.69; P<0.001) and the weighted CST lesion load (R(2)=0.71; P<0.001) were strong predictors of 3-month outcome. In multivariate analyses, controlling for initial upper extremity Fugl-Meyer, weighted CST lesion load, and days-of-therapy, neither the FA laterality index of the cerebral peduncle nor the slope over the FA laterality index of the nearest-5-slices significantly contributed to the prediction of 86% of the variance in the upper extremity Fugl-Meyer at 3 months.
  
  
  
  FA reductions of the CST can be detected near the ischemic lesion in the acute stroke phase, but offer minimal predictive value to motor outcomes at 3 months.
authors.affiliation: From the Neuroimaging and Stroke Recovery Laboratory, Department of Neurology (C.D., J.W., W.F., E.P., G.S.) and Department of Radiology (D.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA; and MUSC Stroke Center, Department of Neurology, Medical University of South Carolina, Charleston (W.F.).
authors.forename: Christopher
authors.initials: C
authors.lastname: Doughty
authors.affiliation: From the Neuroimaging and Stroke Recovery Laboratory, Department of Neurology (C.D., J.W., W.F., E.P., G.S.) and Department of Radiology (D.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA; and MUSC Stroke Center, Department of Neurology, Medical University of South Carolina, Charleston (W.F.).
authors.forename: Jasmine
authors.initials: J
authors.lastname: Wang
authors.affiliation: From the Neuroimaging and Stroke Recovery Laboratory, Department of Neurology (C.D., J.W., W.F., E.P., G.S.) and Department of Radiology (D.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA; and MUSC Stroke Center, Department of Neurology, Medical University of South Carolina, Charleston (W.F.).
authors.forename: Wuwei
authors.initials: W
authors.lastname: Feng
authors.affiliation: From the Neuroimaging and Stroke Recovery Laboratory, Department of Neurology (C.D., J.W., W.F., E.P., G.S.) and Department of Radiology (D.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA; and MUSC Stroke Center, Department of Neurology, Medical University of South Carolina, Charleston (W.F.).
authors.forename: David
authors.initials: D
authors.lastname: Hackney
authors.affiliation: From the Neuroimaging and Stroke Recovery Laboratory, Department of Neurology (C.D., J.W., W.F., E.P., G.S.) and Department of Radiology (D.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA; and MUSC Stroke Center, Department of Neurology, Medical University of South Carolina, Charleston (W.F.).
authors.forename: Ethan
authors.initials: E
authors.lastname: Pani
authors.affiliation: From the Neuroimaging and Stroke Recovery Laboratory, Department of Neurology (C.D., J.W., W.F., E.P., G.S.) and Department of Radiology (D.H.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA; and MUSC Stroke Center, Department of Neurology, Medical University of South Carolina, Charleston (W.F.). gschlaug@bidmc.harvard.edu.
authors.forename: Gottfried
authors.initials: G
authors.lastname: Schlaug
mesh_terms: D000368:Aged; D016880:Anisotropy; D002545:Brain Ischemia / Q000000981:diagnostic imaging; D065850:Cerebral Peduncle / Q000000981:diagnostic imaging; D056324:Diffusion Tensor Imaging; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011712:Pyramidal Tracts / Q000000981:diagnostic imaging*; D020127:Recovery of Function; D020521:Stroke / Q000000981:diagnostic imaging*; D016896:Treatment Outcome
keywords: corticospinal tract; diffusion tensor imaging; lesion load; lesion mapping; magnetic resonance imaging; outcomes assessment; stroke