Intramuscular injection of botulinum toxin for the treatment of wrist and finger spasticity after a stroke

Background Spasticity is a disabling complication of stroke, and it is uncertain whether intramuscular injections of botulinum toxin type A reduce disability in persons with spasticity of the wrist and fingers after a stroke. Methods We performed a randomized, double-blind, placebo-controlled, multicenter trial to assess the efficacy and safety of one-lime injections of botulinum toxin A (200 to 240 units) in 126 subjects with increased flexor tone in the wrist and fingers after a stroke. The primary outcome measure was self-reported disability in four areas: personal hygiene, dressing, pain, and limb position (on a four-point scale ranging from no disability to severe disability) at six weeks; at base line, each subject selected one of these areas in which there was moderate-to-severe disability as the principal target of treatment. Results Subjects who received botulinum toxin A had greater improvement in flexor tone in the wrist and fingers at all follow-up visits through 12 weeks than did subjects who received placebo (P < 0.001 for all comparisons). Subjects treated with botulinum toxin A had greater improvement in the principal target of treatment at weeks 4, 6, 8, and 12 (P < 0.001, P < 0.001, P = 0.03, and P = 0.02, respectively); at week 6, 40 of the 64 subjects in the botulinum-toxin group (62 percent), as compared with 17 of the 62 in the placebo group (27 percent), reported improvement of at least one point on the Disability Assessment Scale in the principal target of treatment (P < 0.001). There were no major adverse events associated with injection of botulinum toxin A. Conclusions Intramuscular injections of botulinum toxin A reduce spasticity of the wrist and finger muscles and associated disability in patients who have had a stroke.