Electroencephalographic and eye movement patterns during sleep in chronic schizophrenic patients

Abstract

Continuous all night sleep EEG recordings were obtained from a group of 25 chronic, hospitalized schizophrenic patients and ten normal control subjects for 5 consecutive nights. Analyses are presented for the second night of sleep. Results for mean percentage of stages I, II, III, IV and I-REM for control subjects were found to be similar to values reported for comparable control populations using similar scoring techniques. In contrast, 40% (N = 10) of the schizophrenic patients failed to manifest any scorable stage IV and were significantly reduced in amount of stage III. For all patients, a reduction in amplitude of the delta wave component of stages III and IV was apparent relative to control subject records. Schizophrenic patients were found to have a more disturbed sleep compared to controls, although no distinction was apparent between patients with or without stage IV present. Differences in time of onset, duration, and number of sleep stage changes were noted between schizophrenic and control subjects. Possible implications arising from the observed disturbance of "slow wave" patterns in the sleep EEGs of schizophrenic patients are discussed in light of research on the loci of this activity in the brain, as well as recent reports linking amino acid levels and EEG sleep patterns.