Scanning eye movements in schizophrenic patients. Relationship to clinical symptoms and regional cerebral blood flow using 123I-IMP SPECT.

Eye movements during the Benton Visual Retention Test were examined using an eye-mark recorder in 32 schizophrenic patients and 32 normal controls. The patients had significantly fewer eye fixations, longer mean duration of fixation and shorter length of mean scan path than the controls. In the patients, these eye movement parameters were significantly correlated with the negative symptom score but not with the positive symptom score on the Positive and Negative Syndrome Scale. These parameters had a significant correlation with the composite score on the Scale for the Assessment of Negative Symptoms (SANS). In particular, they were highly correlated with avolition-apathy and affective flattening or blunting scores on SANS subscales. Thus, examination of scanning eye movements seemed to be a good objective index of negative symptoms. Secondly, regional cerebral blood flow (rCBF) was examined using N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) and single photon emission computer tomography in 17 of 32 patients. With regard to the relationship between the eye movement parameters and rCBF, the mean duration of fixation was negatively correlated with 123I-IMP uptake in the left superior frontal area and left basal ganglia. The mean length of the scan path was correlated with uptake in the left superior frontal area. These findings suggest that the characteristic eye movements of schizophrenic patients are likely to be related with dysfunction of the frontal-basal ganglia neural circuit.