Serial injection of botulinum toxin for muscle imbalance due to regional spasticity in the upper limb.

BACKGROUND AND
PURPOSE: Three-dimensional movement in the upper limb presents a challenge for functional management of regional spasticity. Potential toxicity of botulinum toxin limits the number of muscles which may be injected in any one session. Serial injection may offer a solution, but carries theoretical risk of development of resistance due to antibody formation. This article reviews a small case series, gathered in a post-acute neuro-rehabilitation setting, to evaluate the use of serial botulinum toxin injection in terms of goal achievement and clinical evidence for toxicity or resistance.
METHODS: Nine patients with regional spasticity following acute stroke or brain injury had serial injection of botulinum toxin to muscle groups around the shoulder, elbow and/or wrist. Injection was followed by splinting/physiotherapy as appropriate. Goal attainment scaling was used to assess outcome.
RESULTS: Functional goals achieved were reduction of pain (n=6/7) associated reaction (n=4/5) or care needs (n=5/6), improved gait (n=2/3) or independence in self-care (n=2/5). Two 'golden responder' cases are presented in detail to demonstrate resolution of symptoms with up to four serial injections of botulinum toxin over a period of up to 6 months. No clinical evidence of toxicity or resistance was seen in any case.
CONCLUSION: These preliminary findings suggest that serial botulinum toxin injection followed by appropriate physiotherapy/splinting may provide effective treatment for regional spasticity. Resistance has not presented a problem in this post-acute situation, where treatment has not been required beyond a few months. Ongoing evaluation is underway.