Botulinum toxin A injection in the treatment of hemifacial spasm

Introduction - There are conflicting reports concerning the variation in duration of symptoms relief for patients with hemifacial spasm who have undergone several injections of botulinum A toxin (BOTX-A). We present our experience of BOTX-A injections in Taiwanese patients to analyze this issues, and to inspect whether the efficacy of treatment depends on the pre-injection severity. Material and method - From July 1992 to December 1994, 137 patients received injections of BOTX-A. We used objective and subjective score system to evaluate the efficacy and side effects of BOTX-A injection. Results - The overall successful rate of substantial relief of spasm was 88%. The mean duration of response was 20 weeks. Patents with more severe spasm tended to have shorter duration of improvement. The effects of consecutive injections remained fairly constant over the first 4 injections. Conclusion - The BOTX-A injection is an effective and safe treatment for patients with hemifacial spasm and the effect could be sustained over the consecutive injections.