Botulinum toxin type B improves the speed of reaching in children with cerebral palsy and arm dystonia: an open-label, dose-escalation pilot study.

Seven children between 2 and 15 years of age with cerebral palsy and upper extremity dystonia were enrolled in an open-label, dose-escalation pilot clinical trial of botulinum toxin type B (Myobloc), injected into the biceps and brachioradialis muscles of I or both arms. The primary outcome measure was the change in maximum speed of hand movement during attempted forward reaching. Escalating doses of 12.5, 25, and 50 U/kg per muscle were injected at each of 3 visits. Reaching speed improved in response to injection, and dystonia scores on the Burke-Fahn-Marsden dystonia scale, the Unified Dystonia Rating Scale, and the Unified Parkinson's Disease Rating Scale improved. There was not a dose-related effect on efficacy. There were no serious adverse events. Two children reported transient weakness. These results support the use of botulinum toxin type B as a safe and effective treatment for upper extremity dystonia in children with cerebral palsy. Larger controlled trials are needed to confirm these results.