Electrical stimulation of wrist extensors in poststroke hemiplegia

Background and Purpose-It has been suggested that cyclic neuromuscular elec trical stimulation (ES) may enhance motor recovery after stroke. We have in vestigated the effects of ES of the wrist extensors on impairment of wrist function and on upper-limb disability in patients being rehabilitated after acute stroke. Methods-We recruited 60 hemiparetic patients (mean age, 68 years) 2 to 4 we eks after stroke into a randomized, controlled, parallel-group study compar ing standard rehabilitation treatment with standard treatment plus ES of wr ist extensors (3 times 30 minutes daily for 8 weeks). Isometric strength of wrist extensors was measured using a device built for that purpose. Upper- limb disability was assessed with use of the Action Research Arm Test (ARAT ), Observations were continued for 32 weeks (24 weeks after the finish of E S or the control intervention phase). Results-The change in isometric strength of wrist extensors (at an angle of 0 degrees extension) was significantly greater in the ES group than the co ntrol group at both 8 and 32 weeks (P=0.004, P=0.014 by Mann Whitney U test ). At week 8 the grasp and grip subscores of the ARAT increased significant ly in the ES group compared with that in the control group (P=0.013 and P=0 .02, respectively); a similar trend was seen for the total ARAT score (P=0. 11), In the subgroup of 33 patients with some residual wrist extensor stren gth at study entry (moment at 0 degrees extension >0), the ARAT total score had increased at week 8 by a mean of 21.1 (SD, 12.7) in the ES,group compa red with 10.3 (SD, 9.0) in the control group (P=0.024, Mann Whitney U test) ; however, at 32 weeks the differences between these 2 subgroups were no lo nger statistically significant. Conclusions-ES of the wrist extensors enhances the recovery of isometric wr ist extensor strength in hemiparetic stroke patients. Upper-limb disability was reduced after 8 weeks of ES therapy, with benefits most apparent in th ose with some residual motor function at the wrist. However, it is not clea r how long the improvements in upper-limb disability are maintained after E S is discontinued.