Local injection of botulinum toxin type A for hemifacial spasm.

The preliminary experience of botulinum toxin treatment for hemifacial spasm is reported in this study. Five patients were treated with 10 injections of botulinum toxin in total. Botulinum toxin had a good to excellent effect in all cases. Improvement was observed 2 weeks to 1 month after the injection. The duration of improvement was 0-9 months (mean 4.2 months). The peak rank tended to decrease and the duration of improvement increased after several treatments. Hemifacial spasm caused by the anterior inferior cerebellar artery tended to subside easily. In contrast, compression by the vertebral artery was more refractory. Continuous facial spasm caused by operative trauma subsided after the injection, but paroxysmal spasm still occurred when eating or laughing. Spasm caused by trauma disappeared 4.5 months after the injection. The complications, which were facial nerve paresis in two cases (3 injections, 30%) and diplopia in one case (1 injection, 10%), were transient and subsided in 2 weeks.