Botulinum A toxin for cranial-cervical dystonia: a double-blind, placebo-controlled study.

We studied the effects of botulinum A toxin in 12 patients with blepharospasm and 10 patients with oromandibular-cervical dystonia received in a double-blind manner. All blepharospasm patients improved, 71.6% on a clinical rating score, 60.7% by self-assessment, and 38.9% by video-rating; there was no improvement with placebo. The beneficial effects lasted a mean of 12.5 weeks (range, 5 to 28). Only 37.5% of the patients with oromandibular-cervical dystonia improved. Patients with pharyngeal dystonia and spasmodic dysphonia also improved.