title: Corticospinal excitability as a predictor of functional gains at the affected upper limb following robotic training in chronic stroke survivors.
abstract: BACKGROUND
  Robotic training can help improve function of a paretic limb following a stroke, but individuals respond differently to the training. A predictor of functional gains might improve the ability to select those individuals more likely to benefit from robot-based therapy. Studies evaluating predictors of functional improvement after a robotic training are scarce. One study has found that white matter tract integrity predicts functional gains following a robotic training of the hand and wrist. Objective. To determine the predictive ability of behavioral and brain measures in order to improve selection of individuals for robotic training.
  
  
  METHODS
  Twenty subjects with chronic stroke participated in an 8-week course of robotic exoskeletal training for the arm. Before training, a clinical evaluation, functional magnetic resonance imaging (fMRI), diffusion tensor imaging, and transcranial magnetic stimulation (TMS) were each measured as predictors. Final functional gain was defined as change in the Box and Block Test (BBT). Measures significant in bivariate analysis were fed into a multivariate linear regression model.
  
  
  RESULTS
  Training was associated with an average gain of 6 ± 5 blocks on the BBT (P < .0001). Bivariate analysis revealed that lower baseline motor-evoked potential (MEP) amplitude on TMS, and lower laterality M1 index on fMRI each significantly correlated with greater BBT change. In the multivariate linear regression analysis, baseline MEP magnitude was the only measure that remained significant.
  
  
  CONCLUSIONS
  Subjects with lower baseline MEP magnitude benefited the most from robotic training of the affected arm. These subjects might have reserve remaining for the training to boost corticospinal excitability, translating into functional gains.
authors.affiliation: Université de Sherbrooke, Sherbrooke, Quebec, Canada University of California; Irvine, CA, USA marie-helene.milot@usherbrooke.ca.
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Milot
authors.affiliation: University of California; Irvine, CA, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Spencer
authors.affiliation: University of California; Irvine, CA, USA.
authors.forename: Vicky
authors.initials: V
authors.lastname: Chan
authors.affiliation: University of California; Irvine, CA, USA.
authors.forename: James P
authors.initials: JP
authors.lastname: Allington
authors.affiliation: University of California; Irvine, CA, USA.
authors.forename: Julius
authors.initials: J
authors.lastname: Klein
authors.affiliation: University of California; Irvine, CA, USA.
authors.forename: Cathy
authors.initials: C
authors.lastname: Chou
authors.affiliation: University of California; Irvine, CA, USA.
authors.forename: Kristin
authors.initials: K
authors.lastname: Pearson-Fuhrhop
authors.affiliation: University of California; Irvine, CA, USA.
authors.forename: James E
authors.initials: JE
authors.lastname: Bobrow
authors.affiliation: University of California; Irvine, CA, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Reinkensmeyer
authors.affiliation: University of California; Irvine, CA, USA.
authors.forename: Steven C
authors.initials: SC
authors.lastname: Cramer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002908:Chronic Disease; D056324:Diffusion Tensor Imaging; D019054:Evoked Potentials, Motor / Q000502:physiology; D005081:Exercise Therapy; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D011237:Predictive Value of Tests; D011712:Pyramidal Tracts / Q000098:blood supply / Q000503:physiopathology*; D020127:Recovery of Function; D012371:Robotics; D020521:Stroke / Q000473:pathology*; D000071939:Stroke Rehabilitation; D017741:Survivors; D050781:Transcranial Magnetic Stimulation; D034941:Upper Extremity / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: function; predictor; robot; stroke; training