Somatosensory stimulation enhances the effects of training functional hand tasks in patients with chronic stroke.
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.
Celnik
Pablo
P
Human Cortical Physiology Section and Stroke Neurorehabilitation Clinic, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
Hummel
Friedhelm
F
Harris-Love
Michelle
M
Wolk
Rebecca
R
Cohen
Leonardo G
LG
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