title: Repetitive transcranial magnetic stimulation of contralesional primary motor cortex improves hand function after stroke.
abstract: OBJECTIVE
  A recent report has demonstrated that the contralesional primary motor cortex (M1) inhibited the ipsilesional M1 via an abnormal transcallosal inhibition (TCI) in stroke patients. We studied whether a decreased excitability of the contralesional M1 induced by 1 Hz repetitive transcranial magnetic stimulation (rTMS) caused an improved motor performance of the affected hand in stroke patients by releasing the TCI.
  
  
  METHODS
  We conducted a double-blind study of real versus sham rTMS in stroke patients. After patients had well- performed motor training to minimize the possibility of motor training during the motor measurement, they were randomly assigned to receive a subthreshold rTMS at the contralesional M1 (1 Hz, 25 minutes) or sham stimulation.
  
  
  RESULTS
  When compared with sham stimulation, rTMS reduced the amplitude of motor-evoked potentials in contralesional M1 and the TCI duration, and rTMS immediately induced an improvement in pinch acceleration of the affected hand, although a plateau in motor performance had been reached by the previous motor training. This improvement in motor function after rTMS was significantly correlated with a reduced TCI duration.
  
  
  CONCLUSIONS
  We have demonstrated that a disruption of the TCI by the contralesional M1 virtual lesion caused a paradoxical functional facilitation of the affected hand in stroke patients; this suggests a new neurorehabilitative strategy for stroke patients.
authors.affiliation: Department of Rehabilitation Medicine, Hokkaido University Graduate School of Medicine, Sapporo 060-0814, Japan. naoyuki@med.hokudai.ac.jp
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Takeuchi
authors.forename: Takayo
authors.initials: T
authors.lastname: Chuma
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Matsuo
authors.forename: Ichiro
authors.initials: I
authors.lastname: Watanabe
authors.forename: Katsunori
authors.initials: K
authors.lastname: Ikoma
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D003337:Corpus Callosum / Q000503:physiopathology; D004311:Double-Blind Method; D005260:Female; D006225:Hand / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009048:Motor Skills; D020127:Recovery of Function; D020521:Stroke / Q000503:physiopathology*; D000071939:Stroke Rehabilitation; D013647:Task Performance and Analysis; D050781:Transcranial Magnetic Stimulation / Q000379:methods*