Neurological side effects have been associated with neuroleptic drugs since these drugs were introduced in the treatment of psychiatric disorders. Acute dystonia and parkinsonism may be seen in the initial phases of treatment while a hyperkinetic syndrome may develop later. Fauerby et al. (1964) named this late syndrome tardive dyskinesia. The frequent irreversibility of the syndrome may be regarded as a sign of a potential neurotoxic effect of neuroleptic drugs (Gerlach, 1979).