Natural history of treatment of facial dyskinesias with botulinum toxin: a study of 50 consecutive patients over seven years.

To determine the long-term efficacy of botulinum toxin injections for the treatment of facial dyskinesias we studied 50 consecutive patients with blepharospasm, hemifacial spasm, and Meige syndrome. All received their first injection between September 1983 and June 1984. A total of 520 injections were given; the average number of injections per patient was 10.4 over the seven-year period ending September 1990. Twenty-six (52%) of the patients continued to return for periodic injections, while three patients no longer receive injections since they failed to respond adequately to treatment. Three patients with blepharospasm were in remission and required no further treatment, after a series of six, four, and three injections. Six patients were treated until they died of causes unrelated to facial dyskinesia or its treatment. Six patients are still being treated elsewhere because they could obtain injections closer to their homes. Five of the original 50 patients have been lost to follow-up. A patient with hemifacial spasm had one injection with good result but was not sufficiently bothered by her disease to return for reinjection. Complications were transient, minimal, well tolerated, and did not increase with increased number of injections.