Answers are grounded in this paper and cite their sources.
A double blind placebo controlled crossover trial was performed of botulinum toxin "A" in 20 patients with spasmodic torticollis. There was a statistically significant benefit for those treated with toxin; 12 on toxin improved objectively, compared with four on placebo (p less than 0.04). After a follow up period of one year, 16 still seemed to benefit from repeated toxin injections. The main side effect was dysphagia, which appeared to be dose related in individual patients.
No takes yet. Share an insight, caveat, or question.
Moore et al. (1991) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: