Pharmacologic treatment of severe
dystonia is often unsatisfactory. The atypical
antipsychotic medication clozapine appears to improve
tardive dystonia associated with conventional
neuroleptic use. We studied the efficacy of
clozapine for severe
dystonia in five patients in an open trial. The patient cohort included four with generalized
dystonia and one with
Meige syndrome. All patients were evaluated at baseline and at least weekly while on medication with subjective assessment of response by the patient and physician rating using the Burke-Fahn-Marsden Evaluation Scale for
Dystonia. All five subjects had significant improvement detected by the Burke-Fahn-Marsden Evaluation Scale as well as subjective improvement while on
clozapine. Side effects, such as sedation and
orthostatic hypotension, developed in all patients but was only treatment-limiting in one subject who developed persistent symptomatic
orthostatic hypotension and
tachycardia. Two of the four remaining patients continued
clozapine after completion of the study; an additional patient was uncertain if the benefit outweighed the side effects. One patient discontinued treatment because of difficulty obtaining the FDA-required weekly white blood cell counts for patients on
clozapine. We conclude that
clozapine appears to be effective for generalized and refractory
focal dystonia although its use may be limited by the side effects and need for hematologic monitoring.