Risk factors for spontaneous dyskinesia in schizophrenia.

OBJECTIVE: We describe the prevalence, clinical correlates, and prognostic significance of spontaneous dyskinesias among 100 patients with schizophrenia from the Chestnut Lodge Follow-up Study who had never received treatment with neuroleptic agents up to and including the baseline assessment.
DESIGN: Extensive case records were screened and descriptions of abnormal movements were recorded verbatim for blind rating. Neuroleptic-naive patients with and without abnormal oral-facial movements were compared across sign and symptom, schizophrenia subtype, and illness natural history variables.
RESULTS: Excluding three patients with motor symptoms who had a history of neurologic illness or injury and three who had received prochlorperazine maleate therapy (Compazine), 23% of patient records documented some form of movement disorder; 15% documented oral-facial dyskinesias with sufficient detail so that their presence was considered nearly certain. Compared with patients with schizophrenia without oral-facial movements, patients with oral-facial dyskinesias were more likely to demonstrate a lower IQ score, had more negative symptoms at index admission, and were more symptomatic at follow-up an average of 23 years later. Both the classic hebephrenic schizophrenia subtype and Carpenter's Criteria for the Deficit Syndrome defined high-risk groups for spontaneous oral-facial dyskinesia.
CONCLUSIONS: In previous studies, intellectual impairment and negative symptoms have been described as risk factors for neuroleptic-induced tardive dyskinesia. The present data, however, suggest that in many cases oral-facial dyskinesias in patients with intellectual impairment and negative symptoms may actually represent spontaneous movement disorders associated with hebephrenic or deficit forms of schizophrenia.