title: Somatosensory stimulation enhances the effects of training functional hand tasks in patients with chronic stroke.
abstract: OBJECTIVE
  To test the hypothesis that somatosensory stimulation would enhance the effects of training functional hand tasks immediately after practice and 1 day later in chronic subcortical stroke patients.
  
  
  METHODS
  Single-blinded and randomized, crossover study.
  
  
  METHODS
  Human research laboratory.
  
  
  METHODS
  Nine chronic subcortical stroke patients.
  
  
  METHODS
  Three separate sessions of motor training preceded by (1) synchronous peripheral nerve stimulation (PNS), (2) no stimulation, or (3) asynchronous PNS.
  
  
  METHODS
  Time to complete the Jebsen-Taylor Hand Function Test (JTHFT time) and corticomotor excitability tested with transcranial magnetic stimulation.
  
  
  RESULTS
  After familiarization practice, during which all patients reached a performance plateau, training under the effects of PNS reduced JTHFT time by 10% beyond the post-familiarization plateau. This behavioral gain was accompanied by a specific reduction in GABAergically mediated intracortical inhibition in the motor cortex. These findings were not observed after similar practice under the influence of no stimulation or asynchronous PNS sessions.
  
  
  CONCLUSIONS
  Somatosensory stimulation may enhance the training of functional hand tasks in patients with chronic stroke, possibly through modulation of intracortical GABAergic pathways.
authors.affiliation: Human Cortical Physiology Section and Stroke Neurorehabilitation Clinic, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Pablo
authors.initials: P
authors.lastname: Celnik
authors.forename: Friedhelm
authors.initials: F
authors.lastname: Hummel
authors.forename: Michelle
authors.initials: M
authors.lastname: Harris-Love
authors.forename: Rebecca
authors.initials: R
authors.lastname: Wolk
authors.forename: Leonardo G
authors.initials: LG
authors.lastname: Cohen
mesh_terms: D000328:Adult; D000368:Aged; D001931:Brain Mapping; D002544:Cerebral Infarction / Q000175:diagnosis / Q000503:physiopathology / Q000534:rehabilitation*; D003131:Combined Modality Therapy; D018592:Cross-Over Studies; D004292:Dominance, Cerebral / Q000502:physiology; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D005385:Fingers / Q000294:innervation; D006225:Hand / Q000294:innervation*; D006429:Hemiplegia / Q000175:diagnosis / Q000503:physiopathology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000503:physiopathology; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology; D009048:Motor Skills / Q000502:physiology; D019957:Motor Skills Disorders / Q000175:diagnosis / Q000503:physiopathology / Q000534:rehabilitation*; D018482:Muscle, Skeletal / Q000294:innervation*; D009460:Neurologic Examination; D026741:Physical Therapy Modalities; D011712:Pyramidal Tracts / Q000503:physiopathology; D011930:Reaction Time / Q000502:physiology; D011999:Recruitment, Neurophysiological / Q000502:physiology; D016037:Single-Blind Method; D013003:Somatosensory Cortex / Q000503:physiopathology*; D009435:Synaptic Transmission / Q000502:physiology; D050781:Transcranial Magnetic Stimulation; D004561:Transcutaneous Electric Nerve Stimulation; D014459:Ulnar Nerve / Q000503:physiopathology