RESUMO
OBJECTIVE: To investigate the effect of stochastic resonance stimulation (SRS) on manual abilities in children with hemiplegic cerebral palsy. DESIGN: This pilot study is a randomized, sham-controlled, one-period, crossover trial. SETTING: A neuroscience clinic with specialty therapy programs at an urban, university-based children's hospital. PARTICIPANTS: Sixteen children ages 3 to 16 years who were diagnosed with hemiplegic cerebral palsy and had hand Manual Abilities Classification scale score of I to III with sufficient cognitive abilities to follow instructions. INTERVENTIONS: Children donned wrist and arm bands that delivered SRS via embedded piezoelectric actuators in two randomly assigned conditions: sham (devices powered off) and subthreshold stimulation (SBT-SRS). Following the randomized protocol, a subset of participants also completed an open-label, above-threshold stimulation (AT-SRS) condition. Children carried out the same uni-manual and bimanual tasks during the randomized and open-label protocols; all data were collected in a single session. MAIN OUTCOME MEASURE(S): Box and Blocks (B&B) test, a uni-manual function test, and the Shriners Hospital Upper Extremity Evaluation (SHUEE). The SHUEE was video recorded and scored by two raters who were blinded to the experimental condition. RESULTS: Thirteen children completed the B&B task and 14 children completed the SHUEE. Children in the SBT-SRS condition relative to sham condition moved an average of 1.8 more blocks in 1 minute (p = .08); scored an average of 3 points higher on SHUEE spontaneous functional analysis (p < .002); and scored an average of 2.7 points higher on SHUEE dynamic positional analysis (p = .20). In the open-label protocol, children in the AT-SRS condition relative to sham moved 3.9 more blocks than in the sham condition (n = 8, p < .001); scored an average of 4.5 points higher on SHUEE spontaneous functional analysis (n = 6, p = .08); and scored an average of 10.5 points higher on SHUEE dynamic positional analysis (n = 6, p = .01). CONCLUSION(S): In this pilot study, we found preliminary evidence that children with hemiplegic cerebral palsy demonstrated improved uni-manual abilities and increased function of the impaired hand on bimanual tasks when receiving a single session of SBT-SRS. Preliminary evidence also suggests that some children with hemiplegic cerebral palsy may improve more when receiving a single session of AT-SRS. Future research using larger, controlled studies should evaluate the optimal intensity, duration, and long-term effect of SRS for improving impaired manual abilities.