A randomized, double-blind, placebo-controlled, dose-ranging study to compare the efficacy and safety of three doses of botulinum toxin type A (Dysport) with placebo in upper limb spasticity after stroke

Background and Purpose-We sought to define an effective and safe dose of bo tulinum toxin type A (Dysport) for the treatment of upper limb muscle spast icity due to stroke. Methods-This was a prospective, randomized, double-blind, placebo-controlle d, dose-ranging study. Patients received either a placebo or 1 of 3 doses o f Dysport (500, 1000, 1500 U) into 5 muscles of the affected arm. Efficacy was assessed periodically by the Modified Ashworth Scale and a battery of f unctional outcome measures. Results-Eighty-three patients were recruited, and 82 completed the study. T he 4 study groups were comparable at baseline with respect to their demogra phic characteristics and severity of spasticity. All doses of Dysport studi ed showed a significant I eduction from baseline of muscle tone compared wi th placebo, However, the effect on functional disability was not statistica lly significant and was best at a dose of 1000 U. There were no statistical ly significant differences between the groups in the incidence of adverse e vents. Conclusions-The present study suggests that treatment with Dysport reduces muscle tone in patients with poststroke upper limb spasticity. Treatment wa s effective at doses of Dysport of 500, 1000, and 1500 U. The optimal dose for treatment of patients with residual voluntary movements in the upper li mb appears to be 1000 U. Dysport is safe in the doses used in this study.