Stochastic resonance stimulation for upper limb rehabilitation poststroke.
OBJECTIVE
Previous studies have shown that subthreshold electrical or mechanical noise can reduce the sensory threshold and impart short-term improvements in sensorimotor function. We undertook this study to examine the effects of combined subsensory electrical and vibratory stimulation in conjunction with exercise training on long-term motor performance.


METHODS
Thirty subjects were recruited from adult community-dwelling stroke survivors with residual hemiparesis. Subjects were screened for residual motor ability using a functional task, and those who functioned below this level were excluded. All subjects had a history of a single unilateral ischemic or hemorrhagic stroke at least 6 mos before study entry and were not actively receiving occupational or physical therapy. Subjects were stratified by baseline upper extremity Fugl-Meyer (UEFM) (more impaired [28-35] and less impaired [36-55]) and were randomized to one of two groups: treatment (stochastic resonance stimulation [plus over minus sign] exercise: 15 subjects) and control (sham stimulation [plus over minus sign] exercise: 15 subjects).


RESULTS
No significant difference was found between the stochastic resonance treatment and control group in the UEFM or in any of the secondary measures. The combined group showed modest improvements in UEFM from baseline to completion of therapy (mean improvement, 2.6 points) (P = 0.004); however, these improvements declined by 1-mo follow-up to 1.5 points (P = 0.055). No change in sensory function was detectable.


CONCLUSIONS
Stochastic resonance therapy combined with occupational therapy was no more effective than occupational therapy alone in restoring sensorimotor performance. Other stochastic resonance stimulation montages or protocols might prove more effective.
Stein
Joel
J
Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Boston, Massachusetts, USA.
Hughes
Richard
R
D'Andrea
Susan
S
Therrien
Bethany
B
Niemi
James
J
Krebs
Kathryn
K
Langone
Lisa
L
Harry
Jason
J
D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy; D004599:Electric Stimulation Therapy / Q000379:methods*; D005081:Exercise Therapy; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009788:Occupational Therapy / Q000379:methods; D010291:Paresis / Q000209:etiology / Q000534:rehabilitation*; D020521:Stroke / Q000150:complications; D000071939:Stroke Rehabilitation; D014732:Vibration / Q000627:therapeutic use*