Clinical Availability of Topographic Auditory Event Related Potential P300 as a Biological Marker in Patients with Schizophrenia

Jeon, Yang Whan; Han, Sang Ick; Bang, Seung Kyu

Abstract

This study was designed to investigate the clinical availability of topographic auditory event related potential P300 as a biological marker in patients with schizophrenia. The subjects were composed of normal controls(N=30) and patients(N=30) with schizophrenia by DSM-IV. Topographic auditory event related potential P300 and N100 were measured by "oddball paradigm", which was known as a standard method. Schizophrenics were evaluated twice, initial and follow-up, by 4 week interval. P300 latency and N100 latency were deter-mined by Global Field Power. At this time point the maximum amplitude and its location, according to X-Y coordinates, were determined in brain topography. Clinical symptoms were evaluated by Positive and Negative Syndrome Scale(PANSS). P300 latencies of normal controls, initial group of schizophrenics, and follow-up group of schizophrenics were 315.8+/-24.2msec, 403.8+/-42.3msec, and 364.7+/-43.2msec, respectively. P300 amplitudes of normal controls, initial group of schizophrenics, and follow-up group of schizophrenics were 8.8+/-2.7microV, 4.4+/-1.9microV, and 4.4+/-2.5microV, respectively. They had significantly different P300 latencies one another by measuring ANCOVA, of which covariables were N100 latency, age, and CCP(correct counted percent)(p<0.01). X-Y coordinates was not significant. In P300, there were some different characters between normal controls and schizophrenics even though excluding N100, which was supposed to be exogeneous component by external stimuli. When clinical symptoms were improved, P300 latency was decreased. However, P300 amplitude was not changed. These results suggest that P300 woald be available clinically as a biological marker, P300 latency be a state marker, and P300 amplitude be a trait marker in schizophrenia.