A Experimental Study Of Event-related Potentials P₃₀₀ Of Schizophrenia In Acute Period And Remission Period

Objective To study the abnormalities of P300 in the patients with schizophrenia in acute and remission period, especially the interpeak latencies, and the correlation between P300 and clinical symptoms. To study whether they are the trait marker or the state marker of schizophrenia. Methods 40 schizophrenic patients and 36 normal controls were administered auditory ERPs P300 at Cz, C3, C4 .Symptoms of patients were measured with PANSS. The P300 and PANSS were made in 17 schizophrenic patients once again after a one-month medication.Results The patients with schizophrenia in acute period had decreased P3 amplitude(t=-4. 178,-4.024,-3.715; P=0.000,0.000,0.000), delayed N2 latency (t=3.476,3.745, 3.128; P=0.001, 0.000, 0.002), delayed P2-N2 interpeak latency ( t=3.036, 3.605, 2.133; P=0.004, 0.001, 0.041 ), shortened N2-P3 interpeak latency (t=-3. 194, -3. 298, -3. 058; P=0. 002, 0. 001, 0.003) at Cz, C3, C4 and delayed P2 latency (t=2. 004, 2. 215;P=0. 045, 0. 030) at Cz, C4 than those of normal controls. The P3 amplitude of schizophrenia was correlatednegatively with negative symptoms (r=-0. 403, -0. 430, -0. 357) at Cz, C3, C4, with poverty of reaction (r=-0. 334, -0. 368) at Cz, C4. The P2-N2 interpeak latency was correlated negatively with the total score of PANSS(r=-0.343) and positive symptoms (r=-0.366) at C3, with general symptoms (r=-0. 365, -0. 397) and thought disorders (r=-0. 399, -0. 399) at C3, C4, with activity (r=-0. 415, -0. 366,-0.563) at Cz, C3, C4, with depression (r=-0.389) at C4. The N2-P3 interpeak latency was correlated negatively with the total score of PANSS (r=-0. 363) and general symptoms (r=-0.392) at Cz. After medication, all patients improved clinically, measured with PANSS. The P3 amplitude was still significantly different between schizophrenia and normal controls (t=-3.603,-3.712,-2. 658;P=0.001,0.001,0.010) at Cz, C3,C4; the latency of N2 was longer (t=2. 034, 2. 323;P=0. 047, 0. 024) at Cz, C3; N2-P3 was shorter (t=-2.038;P=0.047) at C3; the latency of P2 was longer (t=2.012; P=0.049) at C4. But they were not correlated with PANSS.Conclusions The P3 amplitude, N2 latency, P2-N2 and N2-P3 interpeak latencies of schizophrenia have obvious abnormalities. The P3 amplitude, the P2-N2 and N2-P3 interpeak latencies have correlations with many clinical symptoms of schizophrenia. The reduction of P3 amplitude may be a trait marker of schizophrenia existing in extensive brain. The N2 latency prolongation may indicate that some of brain areas in schizophrenia have function decline, which is similar to an old man. The P2-N2 interpeak latency may be a state markerof schizophrenia, which reflects many symptoms in acute period. The shortening of N2-P3 interpeak latency is correlated with the abnormality of hippocampal region. It may be another valuable trait marker of schizophrenia.