title: Facilitation of corticospinal excitability by virtual reality exercise following anodal transcranial direct current stimulation in healthy volunteers and subacute stroke subjects.
abstract: BACKGROUND
  There is growing evidence that the combination of non-invasive brain stimulation and motor skill training is an effective new treatment option in neurorehabilitation. We investigated the beneficial effects of the application of transcranial direct current stimulation (tDCS) combined with virtual reality (VR) motor training.
  
  
  METHODS
  In total, 15 healthy, right-handed volunteers and 15 patients with stroke in the subacute stage participated. Four different conditions (A: active wrist exercise, B: VR wrist exercise, C: VR wrist exercise following anodal tDCS (1 mV, 20 min) on the left (healthy volunteer) or affected (stroke patient) primary motor cortex, and D: anodal tDCS without exercise) were provided in random order on separate days. We compared during and post-exercise corticospinal excitability under different conditions in healthy volunteers (A, B, C, D) and stroke patients (B, C, D) by measuring the changes in amplitudes of motor evoked potentials in the extensor carpi radialis muscle, elicited with single-pulse transcranial magnetic stimulation. For statistical analyses, a linear mixed model for a repeated-measures covariance pattern model with unstructured covariance within groups (healthy or stroke groups) was used.
  
  
  RESULTS
  The VR wrist exercise (B) facilitated post-exercise corticospinal excitability more than the active wrist exercise (A) or anodal tDCS without exercise (D) in healthy volunteers. Moreover, the post-exercise corticospinal facilitation after tDCS and VR exercise (C) was greater and was sustained for 20 min after exercise versus the other conditions in healthy volunteers (A, B, D) and in subacute stroke patients (B, D).
  
  
  CONCLUSIONS
  The combined effect of VR motor training following tDCS was synergistic and short-term corticospinal facilitation was superior to the application of VR training, active motor training, or tDCS without exercise condition. These results support the concept of combining brain stimulation with VR motor training to promote recovery after a stroke.
authors.forename: Yeun Joon
authors.initials: YJ
authors.lastname: Kim
authors.forename: Jeonghun
authors.initials: J
authors.lastname: Ku
authors.forename: Sangwoo
authors.initials: S
authors.lastname: Cho
authors.forename: Hyun Jung
authors.initials: HJ
authors.lastname: Kim
authors.forename: Yun Kyung
authors.initials: YK
authors.lastname: Cho
authors.forename: Teo
authors.initials: T
authors.lastname: Lim
authors.affiliation: Department of Rehabilitation Medicine, Eulji Hospital, Eulji University School of Medicine, Hagye dong, Nowongu, Seoul 139-711, South Korea. md52516@hanmail.net.
authors.forename: Youn Joo
authors.initials: YJ
authors.lastname: Kang
mesh_terms: D000328:Adult; D000368:Aged; D019054:Evoked Potentials, Motor / Q000502:physiology; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011712:Pyramidal Tracts / Q000502:physiology*; D000071939:Stroke Rehabilitation; D065908:Transcranial Direct Current Stimulation / Q000379:methods*; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D014584:User-Computer Interface; D014953:Wrist / Q000502:physiology; D055815:Young Adult