The P300 component of event-related potentials in schizophrenic patients

In a pilot study, the P300 component of the ERP subsequent to competitive visual stimulation was examined in 12 schizophrenic patients (paranoid hallucinatory schizophrenia in partial remission, neuroleptic medication). In the competitive stimulation with a varying information content of the non-target stimuli, healthy probands showed a distinct increase in the amplitude of the P300 components according to a in the frequency of the non-target stimuli. The P300 components during these changing stimulatory conditions remained constant in the schizophrenic patients. This reduction in the reactivity of the P300 component subsequent to an increasing information content of the non-target stimuli can be interpreted as a disturbance in the selective information processing. The ability to adequately react to the information content of irrelevant stimuli appears to be reduced in the schizophrenic patients we examined.     

Auditory P300 and eye tracking dysfunction in schizophrenic pedigrees

Several psychophysiological abnormalities associated with schizophrenia have been proposed as genetic trait markers of vulnerability to the disorder. Smooth pursuit eye tracking dysfunction and abnormal long latency event-related potentials are the most promising candidates. Both are independent of the effects of psychotropic medication or mental state at the time of testing, and twin studies demonstrate that each has a high level of heritability. Having recorded smooth pursuit eye tracking and event-related potentials in 20 high-density schizophrenic families, we find abnormalities in one or both measures in most of the families studied. The abnormalities, when present, occur in the family members with schizophrenia and other forms of functional psychosis, and they have a bimodal distribution with approximately half the nonschizophrenic relatives also showing eye tracking dysfunction and/or abnormal event-related potentials. Some of these relatives had psychiatric symptoms; others were normal. Our results suggest that psychophysiological examination can help to clarify the boundaries of schizophrenia spectrum disorder. By helping to decide the phenotypic status of nonschizophrenic family members, this should increase the power of DNA linkage studies.     

精神分裂症患者事件相关电位P300与临床症状关系的研究

目的　探讨精神分裂症P3 0 0 主要指标尤峰间潜伏期的变化及其与临床症状的关系。方法　检测 4 0例精神分裂症患者 (患者组 )和 36名正常人 (对照组 )CZ、C3 、C4电极位置的P3 0 0 ,并用阳性和阴性症状量表 (PANSS)评定患者临床症状。结果　与正常对照组相比 ,在CZ、C3 、C4三点 ,患者组P3波幅低 (P <0 0 1) ,并与阴性症状分呈负相关 (r=- 0 4 0 3,- 0 4 30 ,- 0 35 7) ;N2 潜伏期长 (P <0 0 1) ;P2 N2 峰间潜伏期长 (P <0 0 5和P <0 0 1) ,并与PANSS量表总分、阳性症状、思维障碍、激活性等多种症状分呈负相关 (P <0 0 1～ 0 0 5 ) ;N2 P3 峰间潜伏期短 (P <0 0 1) ,在CZ 点与PANSS量表总分(r=- 0 36 3)和一般症状分 (r=- 0 392 )呈负相关。结论　精神分裂症患者的P3 波幅、N2 潜伏期、P2 N2 、N2 P3 峰间潜伏期有明显异常 ,其中P3 波幅、P2 N2 、N2 P3 峰间潜伏期与多种临床症状呈相关性     

中国精神分裂症患者认知电位P300研究的系统评价

目的 评价中国精神分裂症患者认知电位P300的特点及影响因素.方法 制定原始文献的纳入标准、排除标准及检索策略,检索PubMed、EMBase、Web of knowledge、Cochrane Library、PsycINFO、中国期刊全文数据库、万方数据库、维普中文科技期刊数据库及中国生物医学文献光盘数据库等.应用加强观察性流行病学研究报告的质量(STROBE)为参照评价标准评价文献质量.采用Stata 11软件对满足纳入标准的研究资料进行Meta分析.结果 共有38篇文献符合纳入标准进行Meta分析.随机效应合并分析显示,精神分裂症患者P300波幅低于正常对照组[总效应Z=7.98,合并SMD=-0.937,95％CI( -1.167～ -0.706),P＜0.000 01],潜伏期大于正常对照组[总效应Z＝7.69,合并SMD=0.969,95％CI(0.722～1.215),P＜0.000 01],差异均有统计学意义.敏感性分析结果显示,两组的合并效应结果稳定性均较好.Meta回归显示波幅与检验仪器(P＝0.036)有关,而潜伏期可能与是否用药(P＝0.099)有关.结论 精神分裂症患者存在认知电位P300异常,表现为波幅降低和潜伏期延长,两个指标的稳定性均较好.     

Basic symptoms and P300 abnormalities in young schizophrenic patients.

Among the reasons for the relatively limited number of investigations of self-knowledge phenomena should be included, in addition to theoretical motives, the difficulties regarding the use of instruments available for this kind of approach and their content validity. This study investigates the relationship between subjective and objective deficits in schizophrenia, taking into account subjective experiences of cognitive impairment, clinical symptoms, and cognitive evoked potentials (P300 component). A group of 36 young schizophrenic patients (29 on neuroleptic treatment and seven drug-naive) were considered, together with a comparison group of 36 healthy subjects. Auditory event-correlated potentials (ERPs) were obtained using a simple "oddball" paradigm. Clinical symptoms were rated with the Brief Psychiatric Rating Scale (BPRS) and Scales for the Assessment of Positive and Negative Symptoms (SAPS and SANS), and while subjective disturbances were assessed by the Frankfurter Beschwerde Fragebogen (FBF, also called the Complaint Questionnaire). Correlation analysis showed that P300 amplitude was inversely correlated with subjective experiences of cognitive deficit, especially in the area of automatic skills and overstimulation. No relationship emerged between BPRS, SANS, and SAPS scores and P300 alterations. The results suggest that subjective cognitive disturbances, more than objective symptoms, are related to P300 alterations in schizophrenia, and that the FBF questionnaire appropriately covers the domain of schizophrenic cognitive disorders.     

Transient P300 abnormality of event-related potentials following unilateral temporal lobectomy

Abstract Event-related potentials (ERP) were recorded during auditory oddball tasks for a patient prior to and soon after left anterior temporal lobectomy. The N100 amplitude decreased bilaterally although the latency did not change after the lobectomy. The P300 amplitude decreased in the left hemisphere at 1 and 2 weeks after surgery, then recovered to the pre-operative level at 4 weeks. These findings suggest that the medial temporal structure participates in the generating system of P300.     

精神分裂症患者视觉P300检查与随访

目的：探讨精神分裂症患者Ｐ３异常的意义，以及抗精神病药物可能的影响。方法：对２１例精神分裂症患者在发病期及２年缓解期后采用视觉图像辨认作业引出ＣＺ点Ｐ３００进行研究。结果：病例组发病期与缓解期均有Ｐ３潜伏期延长与波幅下降，较正常对照组统计学意义。结论：Ｐ３可作为一种潜在的认知功能评价工具，应用于精神病学研究。     

The neurophysiological meaning of auditory P300 in subtypes of schizophrenia.

Event-related potentials are a powerful tool to investigate the real-time course of brain electrical mass activation during cognitive processing. In several psychiatric disorders, differences compared to healthy subjects have been reliably described. The specificity and the pathophysiological meaning of the findings were unclear in most studies, however. This review summarizes methodological aspects and findings, in healthy subjects and psychiatric patients, of investigations based on the auditory oddball paradigm, which evokes the P300 component of event-related potentials. Recent convergent results from P300 and brain imaging studies allowed the interpretation of P300 findings in psychotic disorders in terms of different specific and meaningful neurophysiological disturbances. Namely, core schizophrenia is characterized by a left-temporal dysfunction associated with deficits in verbal processing. Acute remitting schizophrenia-like psychoses (cycloid psychosis, ICD-10 F23), on the other hand, show normal hemispheric balance but consistent signs of cerebral hyperarousal. Recent studies further indicate that the drive for action of manic patients does not rely on over-excitation but rather on frontal disinhibition. The findings may help to further advance the understandings and sub-grouping of functional psychoses based on pathophysiological mechanisms.     

The predictive value of P300-amplitudes in the course of schizophrenic disorders

Summary Auditory P300-amplitudes have been found to be correlated with the social functioning and with the impairment in daily life by negative symptoms in cross-sectional studies. In this prospective longitudinal study, the correlation of auditory P300-amplitudes registrated at the index examination was investigated with the clinical outcome after an average of 2.4 years. Based on previous studies, only schizophrenic patients who were in a stabilized residual state were included in the study. Reference-independent P300-parameters of the index examination were correlated with axis V of DSM-III-R (GAP), with the Brief Psychiatric Rating Scale (BPRS) and with the Scale for Assessment of Negative Symptoms (SANS) assessed at the follow-up examination. The correlation of index P300-amplitude with social functioning at follow-up was significant. No correlations of index P300 with the current symptomatology at follow-up, as expressed by BPRS and SANS was found, however. The results indicate a predictive value of the P300-amplitude on the clinical outcome in terms of social functioning of schizophrenic patients.     

精神分裂症患者视觉P_300检查与随访

目的 :探讨精神分裂症患者 P3异常的意义 ,以及抗精神病药物可能的影响。　方法 :对2 1例精神分裂症患者在发病期及 2年缓解期后采用视觉图像辨认作业引出 Cz点 P30 0 进行研究。　结果 :病例组发病期与缓解期均有 P3潜伏期延长与波幅下降 ,较正常对照有统计学意义。　结论 :P3可作为一种潜在的认知功能评价工具 ,应用于精神病学研究。     

精神分裂症患者听觉P300颅脑空间分布的初步研究

目的探讨精神分裂症患者认知电位的脑区域性改变特征。方法应用Ｐ３００地形图的方法，对２４例偏执型精神分裂症患者与５０名正常人进行对比研究。结果患者组内源成分Ｎ２、Ｐ３波幅值在左半球额区、颞区及中央区低于正常人（Ｐ＜０．０５）；外源成分Ｎ１、Ｐ２波幅值高于正常人（Ｐ＜０．０５）。结论提示精神分裂症患者认知电位异常存在着偏侧性和区域性，支持精神分裂症大脑左半球机能障碍的学说。外源成分的改变将有助于精神分裂症的分型诊断     

Reversed temporal region asymmetries of P300 topography in left- and right-handed schizophrenic subjects.

The auditory P300 evoked potential was recorded in 36 subjects: left- (LH) and right-handed (RH) schizophrenic males and LH and RH normal controls. LH and RH normals showed no asymmetry in P300 scalp topography. LH and RH schizophrenics, however, showed lateralized asymmetries in temporal scalp regions: left < right P300 voltage asymmetry in RH schizophrenics and left > right P300 voltage asymmetry in LH schizophrenics. These data suggest that the schizophrenic pathology of P300 neural generators is lateralized according to handedness and provide the first evidence that LH and RH schizophrenics can be dissociated based on left-right voltage asymmetries in P300 topography. These findings further emphasize the need for control of handedness in P300 studies of schizophrenia.     

Differences between paranoid and nonparanoid schizophrenic patients on the somatosensory P300 event-related potential

Event-related potentials were recorded from schizophrenic patients (n = 30) and healthy controls (n = 30) using a somatosensory-reaction-time version of the oddball paradigm, by stimulating the right and the left median nerve. Latency, amplitude, duration and area of the P300 were measured. The patient group was subdivided into a paranoid (n = 16) and a nonparanoid (n = 14) subgroup and each was compared to controls. After stimulation of the right median nerve the nonparanoid group had a significantly prolonged P300 latency and a normal amplitude. The paranoid subgroup had a trend toward reduction of the P300 amplitude; its P300 latency was normal. After stimulation of the left median nerve, a prolongation of the P300 latency was observed in the paranoid subgroup. This subgroup had also a reduced P300 amplitude, while the nonparanoid patients had both values comparable to those of the controls. Duration and area were not significantly different between the two subgroups of patients and controls. Paranoid and nonparanoid patients showed a different behavior on reaction time parameters. No relationship was observed between P300 parameters and clinical ratings, neuroleptic dose and demographic data. The P300 parameters did not correlate with the reaction time measures. These results are discussed in terms of a disturbance of CNS inhibitory mechanisms in cognitive processes of paranoid schizophrenic patients and could be a further indication that different subtypes of schizophrenia may have different biological substrates.     

男性精神分裂症患者攻击行为与脑电图频谱分析及事件相关电位P300的相关性研究

目的 探讨精神分裂症患者攻击行为的脑电生理学预测因子.方法 收集30对有或无攻击行为的男性精神分裂症患者的脑电图频谱分析结果、事件相关电位P＜,300＞测量资料,进行比较和分析,考察影响患者攻击行为的脑电生理学指标.结果 (1)两组简明精神病量表总分及各因子分的差异均无统计学意义(P＞0.05).(2)有攻击组(30例)右侧前额区8波[(23.32±3.30)%]、θ波[(18.22±2.84)%]和右侧额区(F4)[(19.04±3.30)%]和前颞区θ波的相对功率[(17.90±3.29)%]均大于非攻击组[30例;分别为(21.23±3.54)%、(16.54±1.86)%、(17.43±1.98)%、(16.22±1.80)%;P＜0.5].(3)有攻击组Cz点P<,3>潜伏期[(321±45)ms]长于非攻击组[(287±43)ms],P<,3>波幅[(3.4±1.6)μV]低于非攻击组[(4.8±2.2)μV],差异均有统计学意义(P＜0.05).(4)P<,3>潜伏期、F<,4>θ波依次进入回归方程.根据偏回归系数建立的Logistic回归方程总正确预测率为73.3%.结论 P<,3>潜伏期、F<,4>θ波对男性精神分裂症患者攻击行为有较好的预测价值.     

精神分裂症患者认知功能、听觉事件诱发电位P300和脑灰质体积的相关分析

目的 分析经抗精神病药治疗后病情基本稳定但仍残留部分症状的非急性期精神分裂症患者认知功能、听觉事件诱发电位P300和脑灰质体积的相关性.方法 采用听觉事件诱发电位P300、神经心理认知测验对18例非急性期精神分裂症患者(患者组)和18名健康对照者(对照组)进行认知功能检测;采用PANSS和临床总体印象量表(Clinical Global Impression Scale-Severity,CGI-S)评定患者的精神症状,锥体外系副反应量表(Extrapyramidal Side Effects Scale,SAS)、不自主运动量表(Abnormal Involuntary Movement Scale,AIMS)和静坐不能量表(Barnes Akathisia Rating Scale,BARS)评定既往使用抗精神病药的不良反应情况.利用磁共振和脑诱发电位仪分别对患者和对照者进行脑部影像学、神经电生理检查.结果 神经心理认知功能测验中持续性操作测验(Continuous Performance Test,CPT)两位数和三位数测验患者组(2.5±1.2、2.1±1.2)较对照组(3.5±0.6、2.9±0.8)评分低(t=-3.088、-2.563,均P＜0.05);Stroop色词干扰测试的单词、颜色和色词测试总分患者组(77.1 ±16.6、32.4±7.3和32.4±7.3)均较对照组(89.3±8.9、41.8±6.8、41.8±6.8)评分低(t=-2.733、-4.015、-4.015,均P＜0.05);沟槽钉板测验利手和非利手患者组(69.9±10.9、77.3±11.4)较对照组(56.7±7.1、68.7±10.8)完成测试时间延长(t=-4.015、2.313,均P＜0.05);颜色连线2患者组(46.3±18.1)较对照组(37.4±10.6)测试完成时间长(=4.638,P＜0.05);范畴流利测验患者组(11.8±5.1)较对照组(15.6±3.5)评分低(t=-2.593,P＜0.05),2组间比较差异有统计学意义.患者组的P300潜伏期N2(237.1±19.6)与对照组(217.6±26.6)比较延长(=2.966,P＜0.05),波幅差异无统计学意义.P300波幅与迷宫测试、颜色连线及威斯康星卡片分类测验(Wisconsin Card Sorting Test,WCST)正确数呈正相关(r=0.493、0.527、0.512,均P＜0.05),与沟槽钉板、WCST错误数呈负相关(r=-0.571、-0.512,均P＜0.05).患者组的内侧前额叶、右侧颞叶和小脑部分区域的灰质体积较对照组下降,差异有统计学意义,P300潜伏期与局部脑灰质体积(右颞叶的颞上回和颞中回、右后叶小脑扁桃体、右侧小脑后叶、下半小叶)呈负相关(均P＜0.01).结论 非急性期精神分裂症患者的认知功能存在广泛损害.患者内侧前额叶、颞叶、小脑灰质体积异常,且右侧颞叶、右侧小脑局部灰质体积与P300潜伏期相关,提示颞叶、小脑等区域可能是P300异常的脑结构和功能基础.     

P300 subcomponent abnormalities in schizophrenia: III. Deficits In unaffected siblings of schizophrenic probands.

BACKGROUND: Reduced P300 amplitude is a robust finding in patients with schizophrenia. In previous investigations, we reported reductions of specific subcomponents of the auditory oddball P300 that were independent of acute symptomatology and persistent over time, consistent with a trait abnormality. To clarify whether these stable deficits represented genetic markers of vulnerability to schizophrenia, event-related brain potentials (ERPs) from patients were compared to those from their own healthy siblings and unrelated control subjects. METHODS: Auditory P300 ERPs were acquired from 11 schizophrenic patients, 12 healthy siblings and 23 matched control subjects. Five P300 subcomponents were identified using current source density measures: frontal, bilateral parietal, and bilateral temporal. RESULTS: Consistent with previous reports, patients had reduced parietal and frontal P300 amplitudes. The healthy siblings of the schizophrenic probands had an isolated reduction of the frontal P300. CONCLUSIONS: Frontal P300 amplitude is a potential endophenotypic marker of genetic vulnerability to schizophrenia in individuals who otherwise show no evidence of clinical symptomatology. Given the functional interpretation of the frontal P300 as a physiological correlate of cognitive orienting, this supports the hypothesis that impairments of the neural substrate underlying attentional mechanisms are selective indicators of genetic susceptibility to schizophrenia in high-risk individuals.     

P300 in neglect

ObjectiveAttentional deficits have been thought to underlie hemispatial neglect. The present study investigates this using the P300 component of the event-related potential, which is assumed to reflect the allocation of attention.MethodsWe recorded the P300 and oddball detection performance from patients with neglect. Infrequent targets appeared either in the affected contralesional or the unaffected ipsilesional visual hemifield.ResultsContralesional targets produced weaker average P300 responses than ipsilesional ones, but stronger responses than when only distractors were presented. In the affected hemifield, the difference in P300 amplitude between identified and missed targets was correlated with the miss rate. The number of missed contralesional targets for a given participant was positively correlated with the time required for completion of standard neglect tests.ConclusionsThe P300 not only reflects a general attentional impairment in neglect, but also varies as a function of the participants’ awareness of individual stimuli.SignificanceThe findings reflect an important link between attentional dysfunction and impaired stimulus processing in neglect and extinction.     

Clinical subtypes and age at onset in schizophrenic siblings.

This study examines the concordance of clinical subtypes and age at onset of schizophrenia in 42 sibships of multiply affected schizophrenic patients. Subtypes were defined by four major diagnostic systems (DSM-III, DSM-III-R, ICD-10, and Tsuang-Winokur criteria) and rated both for the first hospitalization and long-term diagnosis. When a sibship method was used, no concordance for subtypes was found in siblings. Age at onset, analyzed as a continuous variable with the intraclass correlation method, was found to be correlated in siblings. This finding suggest that the search for continuous traits distributed in families of schizophrenic patients might constitute an alternative to discrete category-based family studies.     

精神分裂症患者事件相关电位P300改变对语词记忆能力的影响

目的探讨精神分裂症患者的语词记忆能力与认知电位之间的相互关系。方法对102例精神分裂症患者首先进行了听觉诱发电位P300测定，然后按有无P300潜伏期延长或/和波幅降低分为P300正常与异常组，再采用选择性提醒测验方法对其进行语词记忆测验。结果P300正常组30例在10次语词记忆测验中通过总例数28例，占93.3%，前6次通过的比例为56.7%；而P300异常组72例在10次语词记忆测验中通过的总例数只有43例，占59.7%，前6次通过的比例只有25%；两组之间的差异非常显著（P〈0.001）。P300异常组回忆总数、保持数、长时再现数及恒定长时再现数减少，而不恒定长时再现数、提醒总数及插入数显著增多，两组比较有显著性差异（P〈0.01）。结论P300异常的精神分裂症患者较P300正常的精神分裂症患者存在更严重的语词记忆障碍。