事件相关电位P300与精神分裂症

精神分裂症(下简称分裂症)病因未明,该病的临床表现、疗效、预后等呈明显的异质性。鉴于精神病学目前还是一门描述性学科,因此寻找分裂症的客观生物学指标,一直是生物精神病学工作者所面临的最赋挑战性的任务。随着脑电生理技术的发展,人们对精神疾病事件相关电位(Event—related potentials,ERPs)—P300(下简称P300)的研究投入了更大的精力,试图在这方面找到辅助诊断分裂症的某些指标。下面复习了分裂症P300研究的新进展。     

强迫症患者事件相关电位P300临床纵向研究

目的：探讨事件相关电位（event-related potentials,ERPs)听觉P300在强迫症（Obsessive-compulsive disovder,OCD)中的应用价值。方法：收集了36例OCD患者,以33例正常人为对照组,进行听觉P300及地形分布图检查,并与临床相关因素进行对比分析。结果：OCD患者潜伏期N2、P3b,波幅P2、P3b与正常对照组相比有显著性差异。P300地形图全部患者失正态分析,84．21％单纯以强迫行为或强迫思维的患者在P300地形图表现为顶叶能量缺乏,而混合性OCD和伴有中度焦虑或忧郁者76．47％表现为顶叶伴左半球能量降低。经治疗疗效显著的P3b改变,波幅增高,潜伏期缩短,P300地形图能量分布趋向正态;治疗无效的P3b及P300地形图改变不明显。结论：事件相关电位P300可作为一项辅助的生物学指标,有助于OCD患者的病理心理研究及临床分型和疗效的判断。     

血管性痴呆患者事件相关电位P300及相关因素研究

目的：研究血管性痴呆患者的事件相关电位P300及相关因素诊断的应用。方法：对42例VD和36例无痴呆脑梗死患者进行听觉P300检测，并进行病因、病变部位等危险因素对比分析。结果：VD组常有高血压、糖尿病、震颤麻痹、皮质下病灶、双侧半球病灶及脑萎缩，并有2次以上座中发生。VD组N1、P2、N2、和P3潜伏期均明显延长，P2、P3波幅分别降低，与对照组比较差异有显著意义（P＜0．01）。结论：高血压、糖尿病、震颤麻痹，反复卒中、皮质病灶、多发性病灶、脑萎缩均是VD的危险因素，与VD的发生、发展有关。事件相关电位P300是一种客观的神经生理学指标，对VD的早期诊断有实用价值。     

Alzheimer病事件相关电位P300的研究进展

AD是老年期痴呆的主要类型之一。认知功能障碍是AD的核心症状。P300对AD的认知评价有重要作用。Goodin(1978)最早报道了AD的P300波幅下降,主要成分P3潜伏期延长。作者还首次提出将P300作为诊断AD的指标,其中P3潜伏期在诊断痴呆中准确率达80％。 P300在临床上反应痴呆的敏感度优于简易精神状况检查得分,目前已广泛应用于AD的诊断,以及治疗效果的评价。国外研究认为P300潜伏期延长可作为临床预测早期认知减退的依据。国内研究提示, AD患者ERP的典型改变为：N2、P3波潜伏期较对照组延长,P3波幅降低。 P300作为患者认知状况评价方法,可能早期发现患者的认知障碍,有利于 AD的早期诊断与治疗。     

血管性痴呆患者事件相关电位P300的检测

目的:检测血管性痴呆患者事件相关电位P300。方法:对40例血管性痴呆患者和38例正常对照组进行听觉P300检测。结果:VD组P2N2和P3潜伏期明显延长,P2P3波幅降低,与对照组比较差异有显著意义(P<0.05)。结论:事件相关电位P300对VD早期诊断有重要意义。     

海洛因依赖者事件相关电位P300的实验研究

近年来国内滥用海洛因的人数逐年上升 ,药物成瘾与流行已构成当今重要的社会问题之一。长期使用海洛因会对人体多系统器官造成不同程度的损害 ,并可产生严重的神经系统并发症和精神障碍。国内外已有研究发现海洛因依赖者存在一定程度的认知功能障碍[1,2 ] 。但应用事件相关电位Ｐ30 0来了解海洛因对认知功能影响的研究尚少见报道。为此 ,我们对 2 2例海洛因依赖者进行Ｐ30 0的检测 ,结果报告如下。1　对象和方法1.1　对象1.1.1　病例组　共 2 2例 ,为 2 0 0 0年 8月至 2 0 0 2年1月在我院住院的自愿戒毒者 ,入院时尿液吗啡定性检测均为阳性…     

视觉事件相关电位（P300）地形图及其应用

一、概念视觉事件相关电位（P300）地形图是一种人们对某种刺激（视觉）事件进行信息加工时,有心理或语言等因素参与的诱发电位地形图,是观察人脑信息加工过程的电位活动的重要手段。它又称为视觉认知电位（cognitive potential）地形图,或称为视觉后发性正相成分（late positive component,LPC）地形图,有的称为视觉联系皮层电位地形图。二、基本方法和原理先做出视觉事件相关电位P300曲线图,然后经过FFT转换为地形图。     

听觉事件相关电位P300对老年痴呆的诊断价值

痴呆是指由于脑部器质性病变，使患者在智能的许多方面发生进行性与持久的衰退，因此实质性地影响其正常生活或经济处理能力。痴呆患者最明显的共同特点是具有各种严重的认知功能障碍，如记忆、定向、计算、思维判断和性格改变等。事件相关电位(ERP)的P300成分与人的认知心理过程有关，是一种客观的神经电生理检查方法，本文对痴呆患者及正常老人进行ERP检测比较，现报告如下。     

慢性肾功能衰竭患者事件相关电位P300研究

目的 :探讨慢性肾功能衰竭患者事件相关电位P30 0的变化特征。方法 :对 32例慢性肾功能衰竭患者进行事件相关电位P30 0测定并以 30例年龄性别匹配的正常人作对照。结果 :慢性肾功能衰竭患者P30 0潜伏期为 40 0 16± 5 1 36ms,波幅为 7 2 0± 4 71μV ,与正常对照组相比有显著性差异 ;P30 0异常率为 90 %,其中PL延长者占 41%(12例 ) ,PL及Amp均异常者 37%(11例 ) ,仅Amp降低者2 0 %(6例 ) ;P30 0异常 (PL延长及Amp降低 )与代谢异常密切相关 ,随代谢异常改善而改善。结论 :事件相关电位P30 0对慢性肾功能衰竭患者认知功能的评定及治疗效果的观察有一定临床意义。     

三音听觉刺激事件相关电位P300的初步研究

目的：观察不同注意状态下三音P300的特点及其初步应用价值。方法：对42名受试者进行三音和传统二音odd-ball诱发P300检测,并将不同状态下的三音P300与二音P300进行比较。结果：低概率靶刺激（r-T)和低概率双靶刺激（r-dT)状态下的P300潜伏期短,波高,二者间无明显差异,低概率非靶刺激（r-nT)P300和二音P300的潜伏期和波幅也无明显差异,但r-T和r-dT与r-nT和二音P300间差异显著。刺激的物理特性和记录部位对三音P300的影响不明显。结论：注意是影响三音P300的重要因素,三音P300反映注意等认知功能的变化方面比传统二音P300更灵敏而准确,有较好的临床应用前景。     

脑白质疏松症患者事件相关电位P300的研究

目的：探讨脑白质疏松症（LA）患者事件相关电位P300成分的特征及与认知障碍的关系。方法：对94例LA患者（其中轻度LA31例,中度LA33例,重度LA30例）和32例正常对照组进行P300检测和简易精神状况检查量表（MMSE）检查。结果：LA患者较对照组MMSE分值降低（P〈0．01）,P300潜伏期延长（P〈0．01）,P300波幅降低（P〈0．05）。轻、中、重度LA患者组间比较MMSE分值降低有差异,P300潜伏期延长有差异（P〈0．01）,但波幅降低有差异仅见于轻、重度LA患者组之间（P〈0．01）。LA组P300潜伏期与MMSE分值间呈负相关（Pz：r=-0．4083,f=4．58,P〈0．01;Cz：r=0．4177．t=4．64,P〈0．01）,P300波幅与MMSE分值间未发现有相关性（P〉0．05）。结论：P300潜伏期可客观评价LA患者的认知功能。     

维持注意与选择注意具有不同的脑机制：来自事件相关电位的证据

BACKGROUND: At present, researches about attention mainly concentrate on the relationship between attention and other psychological phenomena, but studies concerning different types of attention itself (sustained attention versus selective attention) are few. OBJECTIVE: To investigate the brain mechanisms of sustained and selective attentions which have different roles in the cognitive process. METHODS: Event-related potentials (ERPs) were measured when 18 college students’ participants (half male and half female) were performing selective and sustained attention tasks. The program was written in E-Prime and displayed on a computer, and the experimental task was adapted from Karl et al. reported experimental paradigm, including selective attention and sustained attention tasks. The time of fixation point given was 500 ms, and the time of three randomly abreast pictures given was 300 ms. All the participants were asked to make rapid and accurate response as much as possible. RESULTS AND CONCLUSION: The ERPs elicited by the two attention tasks were different in the aspects of time process, wave crest and latency. The brain regions activated by the sustained attention were wider than those by selective attention. The ERPs elicited by the sustained attention mainly presents as positive waves, whereas those elicited by the selective attention were reflected as both positive and negative waves. The EPRs elicited by the sustained attention were N100 and N250, but in the metaphase, selective attention elicited the P180. These may indicate that event choice appears in the middle stage of the task. Besides, the reversion of EPRs elicited by the two attention tasks in the anterior and posterior scalp is likely to be a generality of all attentions. 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

Effects of eye position on event-related potentials during auditory selective attention

Event-related potentials (ERPs) were recorded from normal subjects who received random sequences of tone pips from loudspeakers located to the left and right of a central point. The task was to detect occasional higher pitched tones (targets) from one designated speaker. The negative difference (Nd) wave between ERPs for relevant and irrelevant tones was largest when subjects fixated on the relevant speaker, smallest when subjects fixated on the irrelevant speaker, and intermediate in a central fixation. In addition, the Nd modulation for the left tones was produced by the more negative (or less positive) shift of irrelevant-stimulus ERPs and the less negative shift of relevant-stimulus ERPs associated with fixating away from the relevant speaker. These findings suggest the possibility of both facilitatory and inhibitory effects of eye position on auditory spatial attention. The substantial modulation of ERPs due to eye position also indicated the necessity of fixation control in auditory attention ERP research.     

P300 and alpha event-related desynchronization (ERD)

In the present study we evaluated the relationships between the P300 event-related potential and event-related desynchronization (ERD) of electroencephalographic alpha activity by simultaneously analyzing P300 as well as 7-10- and 10-14-Hz alpha ERD responses from auditory passive and active oddball conditions. We compared the effects of task (target vs. nontarget) and electrode (Fz, Cz, Pz) on P300 and ERD, and correlated P300 amplitude/latency with ERD maximal amplitude/latency across individuals. The major findings were that P300 as well as slow and fast alpha ERD manifested similar task and electrode effects. P300 preceded ERD and predicted individual variance of both slow and fast alpha ERD. The relationships of P300 with alpha ERD were different for the slow and fast alpha frequencies. These findings indicate that P300 and ERD are related such that slow and fast alpha ERDs are specifically guided or modified by the internal event(s) indexed by P300.     

非痴呆性血管性认知损害患者P300的临床研究

目的：观察不同病变部位非痴呆性血管性认知损害（vascular cognitive impairment of non-dementia,VCIND）患者的P300,研究其神经心理学损害特征及可能的病理生理机制,同时探讨P300对早期血管性认知损害（VCI）的诊断价值.方法：对20例皮质下缺血性VCIND患者、20例皮质缺血性VCIND患者及15例正常对照（NC）进行P300检测.结果：与NC组比较,皮质下缺血性VCIND组患者P300潜伏期延长[（366.85±26.43）ms vs（288.33±28.97）ms,P〈0.05],波幅降低[（9.46±1.47）μV vs （13.51±1.30）μV,P〈0.05] 与皮质缺血性VCIND组比较,皮质下缺血性VCIND组患者P300潜伏期延长[（366.85±26.43）ms vs（344.55±23.07）ms,P〈0.05],波幅比较差异无显著意义（P〉0.05）.结论：皮质下缺血性VClND组患者P300异常更为突出,与其神经心理学特征有关 P300潜伏期可能作为早期VCI的诊断参考指标之一.     

P300 sequence effects differ between children and adults for auditory stimuli.

Variation of the P300 component was studied in normal children and adults during an auditory oddball paradigm. In children, the target stimuli that were preceded by a large number of standard stimuli elicited about twice as large P300 with a significantly shorter latency, a more widespread distribution, and an earlier positivity in the frontal area than those that were preceded by a small number of standard stimuli. The P300 variation was not as marked in adults as in children. Based on the context updating theory of the P300, the finding suggests that a long intertarget interval (ITI) results in a profound decay of the neural representation of the target stimulus in children; consequently, more resources are needed to update the neural representation, and the target may even be processed as a novel input. The P300 variation may provide information about the brain functions related to memory, attention, and orienting in children. This variation should be considered when assessing cognitive brain functions with event-related potentials in children.     

Value of event-related P300 subcomponents in the clinical diagnosis of mild cognitive impairment and Alzheimer's Disease

Accurate and early diagnosis of Alzheimer's Disease (AD) with reliable and noninvasive methods is of great importance for clinical practice as effective and specific antidementive therapies become available. The aim of the study was to evaluate the clinical relevance of event-related P300 in the early diagnosis of AD. Thirty patients with AD, 26 patients with mild cognitive impairment (MCI) from our Memory Clinic and 26 age-matched healthy controls (HC) were studied with event-related P300 potentials. Amplitudes of temporo-basal dipoles (TB-P300) were significantly diminished in AD compared to HC and MCI. Furthermore, latencies of temporo-superior dipoles (TS-P300) were significantly prolonged in AD compared with HC. Sensitivity was 90.0% for the differentiation of patients with AD from HC (specificity 79.1%) using reduced TB-P300 amplitudes and prolonged TS-P300 latencies. Similar results were found using Pz amplitudes as well as Fz latencies. Our data suggest that TB-P300 amplitudes and TS-P300 latencies may be an accurate clinically available, nonexpensive, noninvasive, and reliable marker for AD.     

P300 and sleep-related positive waveforms (P220, P450, and P900) have different determinants

Stimulus factors known to influence the amplitude of the well known endogenous event-related potential (ERP) component P300 were manipulated to determine whether they have the same, or a different, influence on the amplitude of positivities of the sleep ERPs identified as P220, P450, and P900. Behavioral responsiveness and ERPs were recorded as subjects moved from wakefulness to sleep while performing an oddball task. The task consisted of sequential presentation of target and non-target tone stimuli with instructions to respond to targets with a finger--lift response. The probability of the target and non-target stimuli was varied (0.2/0.8, 0.5/.05 and 0.8/0.2) across three test conditions. While subjects were awake, P300 was maximal parietally with amplitude inversely related to the relative probability of the evoking stimulus and directly related to its task relevance. Positive waveforms (P220, P450, P900) recorded in sleep were largest at frontal and central recording sites. P220 and P900 amplitudes were inversely related to stimulus probability. P220 was smaller following target relative to non-target stimuli. Processes underlying P220, P450, and P900 sleep-related waveforms are different from those underlying the P300 component seen in alert wakefulness. The sleep positivities may be state-related waveforms subject to modulation by psychological processes.     

认知事件相关诱发电位P300的研究进展

目的 探讨认知事件相关诱发电位（ERP）P300的研究进展。方法 在万方数据、Pubmed等数据库查阅与认知ERP P300研究相关的文献,进行汇总分析。结果 ERP P300反映了大脑认知的加工过程,可对痴呆、脑血管疾病、脑外伤、癫痫、精神疾病等多种疾病进行早期认知减退的检测、认知功能和损害程度的评估以及认知功能的定量分析,具有较广泛的临床应用价值。但P300的临床应用存在没有业内公认的评定标准值、实际检测中影响因素较多等问题,其具体机制及相关问题的解决还有待于进一步更深入地探讨。结论 P300可以检测大脑神经细胞的动态认知过程,具有可靠、有效、客观、无创伤等特点,是其他脑影像技术所不能取代的一种检测方法。未来还需在P300及其亚波的产生定位及临床诊断的统一化标准化等方面做进一步的深入探索和研究。