Botulinum toxin in the treatment of hemifacial spasm.

Thirteen patients with disabling idiopathic hemifacial spasm received botulinum toxin A injections to the affected muscles. Previous treatments, including one posterior fossa decompression, had no sustained benefit. There was excellent response in all the patients with improvement in social disability. Local side effects were mild and transient and include mild facial weakness. One patient had mild diplopia. The benefit lasted more than three months. Reinjection resulted in identical efficacy. Botulinum toxin A injection is a useful therapy for Hemifacial spasm.