Risk factors for spontaneous dyskinesia in schizophrenia

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.

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.

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.

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.