[Cognitive evoked potentials in patients with schizophrenia].

OBJECTIVE: To investigate the features of cognitive evoked potentials (CEPs) in schizophrenics and the changes of CEPs between the duration of episode and remission. METHODS: The present study was made with stimuli of auditory, visual, and somatosensory modalities. CEPs were recorded from 31 episodical schizophrenics and 25 of them were retested when their clinical symtoms rempitted. RESULTS: The episodical patients showed significantly longer A latency (P < 0.05) and PINV latency (P < 0.01), and smaller A-S2' area (P < 0.01). Shorter latency was associated with P2 of auditory evoked potential, visual evoked potential and somatosensory evoked potential (P < 0.05), P1 of AEP, N2 of VEP, and N1 of SEP (P < 0.05). Longer latency was associated with P3 of AEP (P < 0.05). Diminished amplitude was associated with N1-P2 of AEP and N1-P2 of VEP, P2 of VEP, and P2-N2 of SEP (P < 0.05). The follow-up study revealed that when the psychiatric symptoms remitted, the waveform of CEPs became more steady; amplitude B of CNV, N1-P2 of VEP and P2-N2 of SEP were increased (P < 0.05); the amplitude P2 of AEP and VEP, and P1 of AEP were increased into the normal range. CONCLUSION: The variations of CEPs are the state marker of schizophrenia.