Clinical and biological concomitants of resting state EEG power abnormalities in schizophrenia.

BACKGROUND This study investigated the clinical and biological concomitants of electroencephalogram power abnormalities in schizophrenia. METHODS We examined the power characteristics of resting electroencephalograms in 112 schizophrenic patients. Also collected were measures of psychotic symptomatology, brain morphology, ocular motor functioning, electrodermal activity, and nailfold plexus visibility. Seventy-eight nonschizophrenic psychosis patients (e.g., mood disorder patients with psychosis) and 107 nonpsychiatric control subjects were included for comparison. RESULTS Schizophrenic patients whose electroencephalograms were characterized by augmented low-frequency power and diminished alpha-band power had more negative symptoms, larger third ventricles, larger frontal horns of the lateral ventricles, increased cortical sulci widths, and greater ocular motor dysfunction compared with schizophrenic patients without these electroencephalogram characteristics. In nonschizophrenic psychosis patients, augmented low-frequency and diminished alpha-band powers failed to be associated with any clinical or biological indices. CONCLUSIONS Results suggest that clinical and biological concomitants of low-frequency and alpha-band power abnormalities in schizophrenia are unique, perhaps indicating the presence of thalamic and frontal lobe dysfunction.