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.