Tardive stereotypy and other movement disorders in tardive dyskinesias.

We reviewed the medical records and videotapes of 100 patients with tardive dyskinesia (TD) referred to our movement disorders clinic to characterize the spectrum of hyperkinetic movement disorders caused by dopamine receptor blocking drugs (DRBD). Tardive stereotypy, present in 78 patients, was the most common type of TD, followed by tardive dystonia, akathisia, tremor, chorea, and myoclonus. Sixty-four had a combination of these hyperkinesias. In a second study, a "blind" review of videotapes of patients with a variety of movement disorders found that DRBD were the cause of stereotypic movements in 89.3% of patients, and 96.1% of patients with TD had stereotypy. We conclude that stereotypy can be readily differentiated from other hyperkinetic movement disorders and that its presence in an adult is highly suggestive of prior exposure to DRBD.