Changes in blink rates of Nigerian schizophrenics treated with chlorpromazine.

Chlorpromazine was administered over a 4-8 week period to 40 schizophrenic patients who had not received previous neuroleptic drug treatment out of a total of 222 schizophrenic patients seen during the study period. Pre-treatment spontaneous eye blink rate was high in the 40 schizophrenics when compared to 34 normal controls, (22 vs 14 blinks/min respectively, t = 17.04, df = 72, p < 0.001). Clinical improvement in the schizophrenic patients correlated with a significant reduction in their pre-treatment versus post-treatment spontaneous eye blink rate (22 vs 9 blinks/min, t = 18.83, df = 78, p < 0.001). The blink rate in the clinically-well schizophrenic patients did not however, reach the level obtained in the normal controls but rather was lowered significantly (9 vs 14 blinks/min, t = 8.11, df = 72, p < 0.001). Blink rate changes in schizophrenic patients on neuroleptic treatment may serve as a quick bedside assessment of clinical improvement and can also be a pointer to those patients who may have sub-clinical drug induced parkinsonism.