An open-label study of botulinum toxin A for treatment of tardive dystonia.

Tardive dystonia is a form of tardive dyskinesia for which there is little satisfactory treatment. We reviewed our experience at four movement disorder centers in the treatment of tardive dystonia with botulinum toxin A (BTX-A). Thirty-four patients with relatively localized tardive dystonia unresponsive to oral medications were treated with injections of BTX-A into dystonia muscles. Cervical dystonia was the most frequent manifestation of tardive dystonia in this group of patients. There was marked or moderate improvement in 29 of 34 patients. Eighteen of 24 patients with cervical dystonia showed either marked or moderate improvement. In this retrospective review, BTX-A provided useful symptomatic treatment for localized dystonia in patients with tardive dystonia unresponsive to other treatment. A controlled, prospective trial of BTX-A in tardive dystonia is warranted.