Movement disorders, associated with organic central nervous system conditions, e.g. Huntington's chorea, hemiballismus and senile chorea.Moderate to severe tardive dyskinesia, which is disabling and/or socially embarrassing. The condition should be persistent despite a switch to atypical antipsychotic medication and/or reduction in dosage of antipsychotic medication, when withdrawal of antipsychotic medication is not a realistic option.