具有暴力行为的精神分裂症患者病情缓解阶段事件相关电位N270的变化

Event-related potential N270 in remitted schizophrenia patients with violence behavior

目的初步分析事件相关电位N270在具有暴力行为精神分裂症患者病情缓解阶段中的变化特点。方法采用颜色匹配和冲突的图片刺激对随机呈现给受试者。应用美国EGI256导联高密度脑电仪器记录24例具有暴力行为精神分裂症患者（患者组）和25名年龄、性别匹配的健康对照（对照组）在颜色匹配和冲突图片刺激下的事件相关电位，并收集受试者在判断每对刺激的颜色是否匹配时所作出相应按键反应的正确率和反应时。结果（1）无论在颜色匹配还是颜色冲突时，患者组和对照组正确率的差异均无统计学意义（P〉0．05），患者组的反应时长于对照组[匹配：患者组（774．17±231．25）ms，对照组（642．28±185．56）ms，t=2．206，P=0．032；冲突：患者组（835．35±246．79）ms，对照组（681．19±207．87）ms，t=2．369，P=0．022]。患者组和对照组在颜色冲突状态下的反应时均长于颜色匹配状态的反应时（P〈0．05）。（2）与对照组相比，患者组在F3、F4、C3、C4、Fz、Cz脑区的N270潜伏期延长（P〈0．05），波幅降低（P〈0．05）。（3）与对照组相比，患者组在F3、F4、C3、Fz、Cz脑区的N270差异曲线的波幅降低（P〈0．05），F3、F4、C3、C4、Fz、Cz脑区的潜伏期延长（P〈0．05）。结论具有暴力行为精神分裂症患者在病情缓解阶段对冲突信息的加工过程存在损害，可用N270来监测和评价。

Objective To explore the cognitive impairments of schizophrenia patients with violence （Sch） in remission and to verify the feasibility of N270 as a clinical examination method to evaluate the cognitive state of schizophrenic patients. Methods Stimulus pairs with identical （match condition） or different （conflict condition） colors were randomly presented to all subjects. Twenty-four Sch patients and twenty-five age-matched normal controls （NC） determined if the two stimuli in a pair had the same color while ERPs were recorded from their scalps, using EGI （Electrical Geodesics Inc. , Eugene, OR） 256 high density EEG. Results （1） No significant difference on reaction accuracy were found between Sch and NC groups regardless of identical or different colors （ P 〉 0. 05 ）, and Sch group showed more delayed reaction time than NC group[identical： Sch（774. 17 ±231.25） ms, NC （642. 28 ± 185. 56） ms, t =2. 206, P = 0.032; different： Sch（835.35 ±246.79） ms, NC （681.19 ±207.87） ms, t =2.369, P=0.022]. Reaction time under condition of different color was longer than that of identical color in Sch and NC groups （P 〈 0. 05）. （2） Sch group showed more delayed N270 latency and decreased N270 amplitude than NC group （P 〈 0. 05） at F3, F4, C3, CA, Fz, Cz sites. （3） Sch group showed more decreased amplitude of N270 difference wave than NC group at F3, F4, C3, Fz, Cz sites （ P 〈 0.05 ）, and more delayed latency of N270 difference wave than NC group at F3, F4, C3, C4, Fz, Cz sites （P 〈 0. 05 ）. Conclusions Schizophrenia patients with violence in remission show cognitive deficits, N270 is probably an effective index to detect the cognitive impairment in schizophrenic patients.