RR-PL-0228

Sunday 15:20, Palau de Congressos, Hall 2, Room D

EMG-TRIGGERED ELECTRICAL STIMULATION ON HAND FUNCTION RECOVERY AND CORTICAL REORGANIZATION IN SUBJECTS WITH STROKE. Kimberley TJ, Carey JR.; University of Minnesota, Minneapolis, MN, USA. PURPOSE:  Cortical reorganization and functional hand movement recovery in subjects with stroke were studied following intensive home use of EMG-triggered electrical stimulation. RELEVANCE: This study shows that individuals with chronic stroke who have impaired hand function can be trained to successfully use an electrical stimulator at home and improve their functional hand performance after an intensive period of use.  SUBJECTS: Sixteen subjects with chronic left- or right-sided hemiplegia (stroke duration range: 7-74 months) and residual impaired hand function. METHODS AND MATERIALS:  Subjects were studied with functional magnetic resonance imaging (fMRI) and functional hand performance measures.  Subjects were randomly assigned to a treatment or sham group. The dependent variables consisted of a Box and Block Test, Jebsen Taylor Hand Function Test, Motor Activity Log (MAL), isometric finger extension strength, a finger movement tracking accuracy score, and quantification of the active cortical areas using fMRI. Functional whole brain images were collected from the subject with a 4 Tesla magnet during the tracking task. In the treatment group, between the pretest and posttest, the subjects used the stimulator independently for 60 hours over the course of 3 weeks on extensor muscles to facilitate hand opening and wrist extension. Between pretest and posttest the sham group received sham stimulation (no current was delivered).  This group then crossed over, received the real treatment, and was tested a third time.  ANALYSIS:  Change from pretest to posttest for each of the dependent variables was analyzed with paired t-tests.  Cortical activation data was analyzed with GLM repeated measures analysis. Statistical significance was set at p < 0.05. RESULTS: Treatment subjects demonstrated significant improvement in the Box and Block score (p=0.041), isometric finger extension strength (p=0.009), MAL: amount use (p<0.001), and Jebsen: picking up small objects (p=0.010), stacking (p=0.010), lifting heavy cans (p=0.002). Sham subjects improved in isometric finger extension strength only (p=0.01).  Following cross-over, these subjects improved on the same measures as the treatment group, and in addition, the MAL: how well (p=0.019), Jebsen: page-turning (p=0.015). Cortical activation did not increase following the electrical stimulation treatment. CONCLUSION: This study also shows that electrical stimulation does not appear to cause an increase in activation in a particular brain area, implying, based on earlier work, that active engagement may be a critical factor required to stimulate brain reorganization. It goes on to show that functional improvements may occur without training in a functional task and that electrical stimulation may be an effective tool to facilitate hand opening in stroke subjects.