Long-term treatment of involuntary facial spasms using botulinum toxin.

Botulinum toxin, a powerful pre-synaptic neurotoxin produced by Clostridium botulinum, interferes with the release of acetylcholine from nerve terminals. Since September 1985, we have been using this toxin to treat altogether 62 patients with benign facial spasms. Most of the patients had been on drugs or psychotherapy, 2 had received alcohol injections, 2 had undergone surgery of the orbicular branch, and 2 electrocoagulation of the facial nerve. In essential blepharospasm the duration of the beneficial effect after each treatment with botulinum toxin was about 3 1/2 months. In patients with hemifacial spasm the response was clearly longer, nearly 5 months in most cases. The treatment gave the best and longest-lasting relief of symptoms in patients suffering from disturbing myokymia. Response was poorest in patients suffering from facial spasms who simultaneously had a severe psychiatric disease. The most frequent side effect was mild or moderate ptosis (22.6%). Some patients complained of dry eyes and a few cases displayed facial nerve paresis. Side effects caused by botulinum toxin injections are transient but so also, unfortunately, is the beneficial effect on facial spasms.