Botulinum toxin type B in upper-limb poststroke spasticity: A double-blind, placebo-controlled trial

Objective: To determine whether botulinum toxin type B (BTX-B) is effective in controlling upper-limb spasticity. Design: A single-site, double-blind, placebo-controlled, ran-domized trial and open-label study. Setting: Outpatient. Participants: Subjects with an Ashworth Scale score of 2 or more at the elbow, wrist, and fingers. Interventions: Subjects were injected with 10,000U of BTX-B or placebo at the elbow, wrist, and finger flexors. Main Outcome Measures: Measures recorded at weeks 0, 2, 4, 8, 12, and 16, with a 12-week open-label study. Ashworth Scale score, a global assessment of change (GAC), adverse events and mouse neutralization antibody testing. Results: BTX-B did not decrease muscle tone in the elbow, wrist, or finger flexors at 10,000U over the 16-week period. A decrease in Ashworth Scale score for the BTX-B patient group was present at the wrist at week 2 of the double-blind study (P=.003) but was not statistically significant at other visits. In the open-label study, improvement was noted at week 4 for the elbow (P=.039), wrist (P=.002), finger (P=.001), and thumb flexors (P=.002). In the double-blind study, the Physician GAC did not reach significance. Dry mouth was reported by 8 of 9 BTX-B subjects in the double-blind study. Mouse neutralization antibodies were negative. Conclusions: Our study does not show a significant decrease in tone from 10,000U of BTX-B. Dry mouth was common.