Botulinum Toxin Injection for Hypertonicity of the Upper Extremity Within 12 Weeks After Stroke: A Randomized Controlled Trial

Background. Botulinum neurotoxin type A (BoNT-A) reduces upper-extremity poststroke spasticity when given 6 or more months after stroke. Effects on functional use of the arm and hand are less apparent. Objective. To determine the effect and safety of very early use of BoNT-A for patients with upper-limb spasticity. Methods. The Asia Botulinum Toxin-A Clinical Trial Designed for Early Post-stroke Spasticity (ABCDE-S; NCT00234546) was a multicenter, randomized, placebo-controlled trial conducted in patients recruited within 2 -12 weeks of first-ever stroke. Participants with a Modified Ashworth Scale (MAS) score of 1+ or above received BoNT-A (Dysport) 500 U or placebo to one or more wrist and elbow mover muscles, plus unstructured rehabilitation. The primary outcome was the MAS score in the most affected joint 4 weeks after first injection. Follow-up was 24 weeks. Results. A total of 163 patients were enrolled and assigned to placebo (n = 83) or BoNT-A (n = 80). Mean time since stroke was about 7 weeks. At 4 weeks postinjection, BoNT-A significantly improved MAS scores. Treatment effect-size estimates increased with higher baseline MAS scores from 0.45 (Q1) to 0.70 (Q3). MAS scores for all secondary end points improved with BoNT-A versus placebo at all time points (P < .0001, all visits). The Functional Motor Assessment Scale did not reveal clinically significant differences. No group differences in adverse events were found. Interpretation. BoNT-A 500 U can provide a sustained reduction in poststroke upper-limb spasticity when combined with rehabilitation in Asian patients who have mild-to-moderate hypertonicity and voluntary movement, within 2 -12 weeks of stroke. Functional use of the arm and hand was not affected.