Pharyngeal paralysis due to botulinum toxin injection.

Botulinum toxin injection is now recognized as an effective treatment for spasmodic torticollis. Complications of this increasingly popular method of treatment include mild and transient dysphagia, with or without dysphonia, lasting up to four weeks. Two cases of paralysis of vocal cord contralateral to the injected sternomastoid have also been reported. A case of severe dysphagia lasting six weeks associated with ipsilateral vocal cord palsy following botulinum toxin injection is presented. The probable mechanism for these complications is discussed.