| Objective 1. To study the variation characteristic ofevent-related potentials P300(ERP-P300, P300) subcomponents of schizophrenic patients in episodic and remitted state. 2. To investigate the variation characteristic of P300 subcomponents in different subtypes of schizophrenia. 3. To investigate the correlation between the schizophrenic psychopathology and P300 subcomponents.MethodsSubjects Fourty consecutive schizophrenic patients who met CCMD-3 criteria for schizophrenia and thirty-six normal volunteers served as the control group matched for schizophrenic at sex, age and marrige.All patients and normal controls were right-handed.Procedure The P300 indexes of all patients with schizophrenic and normal controls were measured. Clinical symptom of all the patients at the time of testing was assessed in a semi-structured interview by two trained vaters using Positive and Negative Syndrom Scale (PANSS). The classical 7-itern PANSS positive and 7-itern PANSS negative scores were computed.Equipment The P300 measures were recorded by American Nicolet Bravo instrument.Mensurement Target P3a, P3h latencies and P3a,P3b amplitudes were collected during and auditory "oddball" target detection task.Date analysis The SPSS V10.0 for windons statistical package was used throughout.Results 1. Compared to normal controls ,schizophrenic patients showed reduced P3a, P3b, amplitudes at four electrode (C3, C4,C2,Pz) sites. P300 subcomponent amplitudes of schizophrenics did not change over 4 weeks along with their clinical improvement. 2. Compared to normal controls, negative subtype of schizophrenics showed reduced P3a, P3b amplitudes at (C3, C4,Cz,Pz) electrode site (P < 0. 01) .however, positive subtype of schizophrenics only showed reduced P3b amplitudes at Cz electrode site . There were significant difference between two different subtypes of schizophrenia concerning effects on P3a, amplitudes at electrode site (C4). There was not significant difference among groups concerning effects on P3a,,P3b latencies at four electrode sites. 3. Negative symptoms score correlated negtively with the P3a,P3b amplitudes at four electrodes (C3,C4, Cz, Pz) in episodic but not in remitted state.Conclusions 1. The recorded P300 subcomponents differences between schizophrenic patients and normal controls groups reflected worsened brain cognitive function extensively in schizophrenic patients group. The variations of P300 subcomponents amplitudes might be the trait markers of scizophrenia 2. These findings suggest that different subtype of schizophrenics possibly display different basi s of neurobiology. 3. Its suggestionthat the P300 subcomponent might be an important approach to etiopathology of schizophrenia, and may have more clinical value to valuate the degree of congnitive disfunction of schizophrenia. |
