Controlled trial of botulinum toxin injections in the treatment of spasmodic torticollis.

We administered local injections of botulinum toxin to 20 patients with torticollis in a blinded, placebo-controlled study. Each patient received four sets of injections: three different doses of botulinum toxin and one placebo. The order of the sessions was random and unknown to the patients. Sixteen of the patients (80%) reported subjective improvement to at least one dose of botulinum toxin; 11 (55%) reported substantial improvement. No objective benefit was documented. Side effects were minor and transient, although dysphagia occurred in four. Some patients reported that the effect waned despite persistent relaxation or even flaccidity of previously overactive muscles, suggesting a change in the pattern of muscle activity after botulinum toxin injections.