Cerebral blood flow and event-related potential in patients with cerebral infarction

Cerebral blood flow (CBF) and P 300, a long-latency positive component of the scalp-recorded event-related potential (ERP) associated with cognitive processing were investigated in patients with cerebral infarction to elucidate the relationship between CBF and cognitive function. Twenty-five patients with cerebral infarction with a mean age of 66.8 years were studied. ERP was recorded during auditory discrimination tasks. The latency of the P 300 from Pz region was recorded. The regional CBF was measured by the 133Xe inhalation method. The F1 (cortical gray matter flow) values were calculated using the Obrist's method. The mean F1 values in patients with cerebral infarction were significantly lower compared to the values obtained for the 15 control subjects (mean age, 68.4 years) (p less than 0.01). Patients with cerebral infarction showed significant prolongation of the P 300 latency compared to the 20 control subjects (mean age, 64.4 years) (p less than 0.02). There was a significant correlation between the P 300 latency and the mean F1 values in patients with cerebral infarction (p less than 0.01). Present results suggest that the cognitive impairment with respect to ERP may be related to the reduction of cortical blood flow in patients with cerebral infarction.     

Neuroelectric assessment of HIV: EEG, ERP, and viral load.

The effects of the human immunodeficiency virus (HIV) infection on the central nervous system function were studied with electroencephalographic (EEG) and auditory event-related brain potentials (EPRs) in patients infected with HIV and unaffected young adult control subjects (n=10/group). All subjects were assessed once every 15 min for four trial blocks at the same time of day to assess EEG/ERP changes with time on task-induced fatigue. Spectral analysis was applied to the pre- and post-stimulus EEG segments. ERP values were evaluated with respect to group differences for component amplitude and latency measures. Spectral analysis demonstrated that HIV patients evinced greater pre-stimulus delta power over frontal areas compared to control subjects, and less post-stimulus spectral power for the delta, theta, and alpha bands over the central/parietal areas. P300 amplitude was smaller, and latency was marginally longer for the HIV patients compared to control subjects. P300 latency correlated positively with increases in the patient HIV viral load. Time-on-task generally did not affect EEG or ERP measures for either group other than contributing to an overall decrease in neuroelectric responsivity. Group spectral power effects were consistent with differences in arousal/fatigue level. P300 group differences were consistent with declines in cognitive capability, and P300 latency increased with increased viral load. HIV infection negatively affected central nervous system function as measured by EEG and cognitive ERPs in a manner that suggests decreased arousal and increased fatigue in HIV patients.     

Auditory event-related potential abnormalities in bipolar disorder and schizophrenia.

Auditory P300 latency prolongation or amplitude reduction has been reported in patients affected by bipolar disorder and in schizophrenia. The purpose of this study was to test whether the auditory P300 and earlier event-related potential (ERP) components elicited during an auditory discrimination task could differentiate between these two disorders. Thirteen patients with manic or mixed bipolar disorder, 12 patients with schizophrenia, and 24 control subjects were evaluated. None of the subjects had a history of alcohol or substance abuse or dependence. ERPs were elicited during an auditory discrimination task in which a subject pressed a key to infrequent 1500 Hz tones interspersed amid a series of 1000 Hz tones. The amplitude and latency of N100 and P200 were measured from ERPs to non-target tones, and N200 and P300 were measured from ERPs to target tones. N100, P200 and N200 amplitudes were reduced in schizophrenia patients, but not in bipolar patients. Both bipolar disorder and schizophrenia patients showed reduced P300 amplitude and prolonged P300 latency. Amplitude reduction in the early ERP components implicates auditory processing deficits in schizophrenia. Both groups showed reductions in P300 amplitude, suggesting a disturbance of the temporal-parietal generators of this component. Prolonged P300 latency is consistent with impaired attentional processing in schizophrenia and symptomatic bipolar disorder patients.     

癫癎患者听觉事件相关电位的检测报告

目的:探讨听觉事件相关电位(ERP)在癫癎患者中的应用价值。方法:对40例癫癎患者和30名正常人进行ERP检测比较,并将癫癎患者ERP的结果与其发作类型、用药情况等进行比较分析。结果:40例癫癎患者的ERP P300潜伏期较对照组延长(P<0．05),但其P300波幅差异无统计学意义(P>0．05)。全身强直阵挛性发作的28例癫癎患者,P300潜伏期延长尤著。多药治疗组较单药治疗组P300潜伏期延长。结论:癫癎患者存在认识功能障碍,ERP可作为癫癎患者认知功能障碍诊断的参考指标,对指导临床,及早给予干预和治疗有一定意义。     

Habituation of event-related potentials in patients with Parkinson's disease

Auditory event-related potential (ERP) was studied in idiopathic Parkinson's disease (PD) using our new procedures. We examined 12 non-demented patients with PD, and 9 age-matched control subjects. Ninety responses induced by rare stimulation were continuously recorded from Fz, Cz, Pz referred to linked earlobe electrode (A1A2), and were divided into nine blocks (one block = 10 responses) for statistical analysis. We assessed the habituation of auditory ERP to detect delicate changes related to the information processing in PD. N100 and P300 latencies were significantly longer in PD than in control subjects (p<0.05). P300 latency gradually increased with progression of recording blocks in both PD and control subjects, whereas N100 latency increased only in PD. Three way analysis of variance for P300 amplitude revealed significant effects of subject group, recording electrode site, and trial block. P300 amplitude was smaller in PD than in control subjects. Significant negative correlation between P300 amplitudes and block numbers were observed at Cz and Pz in PD, and at Fz in the control group. Previous reports as well as present results suggest that prolongation of N100 latency might be related to frontal lobe dysfunction, and abnormality of P300 to dysfunction in both the frontal lobe and hippocampus in PD.     

Meta-analysis of P300 and schizophrenia: patients, paradigms, and practical implications

The goal of the present meta-analysis was to identify factors that contribute to P300 event-related brain potential (ERP) differences in patients with schizophrenia compared to unaffected controls in an attempt to characterize the clinically relevant dimensions underlying P300 deficits in patients with schizophrenia. P300 effect size (d) was smaller in amplitude and longer in latency in schizophrenic patients compared to normal controls, with the strongest effects obtained from the auditory oddball. Paranoid subtype demonstrated larger P300 amplitude effect sizes than other disease subtypes, and P300 latency effect size decreased with disease duration. Psychopathology severity and antipsychotic medications were unrelated to P300 amplitude effect size. Gender proportion, educational level, and stimulus and task variables also affected P300 amplitude and latency effect sizes. The findings are used to formulate a theoretical account of the empirical data and provide suggestions for maximizing the utility of the P300 component in the assessment of schizophrenia.     

Response mode and P300 from auditory stimuli

The P300 component of the event-related brain potential (ERP) was elicited with a simple auditory discrimination task. Subjects were required to respond in three different ways to target stimuli across conditions: (1) silently counting the targets; (2) tapping their index finger every time a target was detected; or (3) pressing a button with their thumb when a target was presented. In addition, ERPs were recorded during each response mode while the subjects' eyes were either open or closed. P300 amplitude was larger for the counting compared to the tapping or button press tasks especially during the eyes closed condition. The peak latency of the P300 was longer when obtained from the counting compared to the tapping and button-press tasks for both eye conditions. Response mode also interacted with electrode site for peak latency. The results suggest that the P300 ERP component is sensitive to the nature of the subject's response during discrimination tasks.     

气功锻炼辅助治疗对帕金森病患者事件相关电位的影响

目的：观察帕金森病人气功辅助治疗前后事件相关电位（ＥＲＰ）的变化。方法：对３３例药物治疗中期的帕金森病人作气功辅助治疗３个月,观察治疗前后的听觉ＥＲＰ的Ｐ３００,并与正常对照组２４例比较。结果：帕金森病人ＥＲＰ与对照组存在多指标差异,以Ｐ３潜伏期延长为甚,气功锻炼后其Ｎ２、Ｐ３潜伏期缩短,与对照组比较无显著性差异;同时临床症状也获得改善。结论：帕金森病人有认知功能受损,气功辅助治疗可使其获得改善或恢复。     

梗塞性脑血管病事件相关电位研究

脑血管病是老年期痴呆的常见原因。脑梗塞患者约有2％～5％出现智能障碍。利用听觉刺激序列诱发的事件相关电位(P_(300)),对32例脑梗塞患者进行了临床研究。32例患者采用长谷川智测量表(HDS)评分。其中9例小于20分,其P_(300)潜伏期与正常对照组均延长,而23例HDS评分正常者其中10例P_(300)潜伏期延长。研究结果提示利用事件相关电位检测技术可早期发现脑梗塞患者亚临床痴呆。     

网络成瘾青少年事件相关电位P300的溯源研究

目的：利用偶极子溯源分析方法,探讨网络成瘾青少年事件相关电位（ERP）P300成分的脑内起源。方法：网络成瘾青少年和正常对照者各10例,采用视觉Oddball范式对被试进行刺激以诱发ERPP300成分,利用偶极子溯源分析方法对P300的脑内起源进行定位,并将溯源后P300的起源位置和fMRI中与网络成瘾相关的脑区进行对比,了解两者的相关性。结果：网络成瘾组与对照组相比,ERPP300波的峰潜伏期缩短、波幅升高;总平均P300电位波溯源定位在扣带回中后部,fMRI中发现网络成瘾青少年在接受网络内容刺激后扣带回中后部也出现明显的激活。结论：网络成瘾青少年P300电位的脑内起源主要位于扣带回中后部,该部可能参与了网络成瘾的形成。     

The relationship between the visually evoked P300 event-related potential and gamma band oscillation in the human medial and basal temporal lobes: an electrocorticographic study

We have recorded electrocorticographic activities (ECoG) from subdural electrodes on the human medial temporal lobe (MTL) and basal temporal lobe (BTL) in epileptic patients during cognitive visual tasks designed to evoke the P300 event related potential (ERP). From those recordings we examined the event related gamma band oscillation (ERGBO) and P300 ERP. While P300 was predominantly observed in the MTL, ERGBO was observed in both MTL and BTL. Resembling to P300, ERGBO responses were more often observed following rare stimuli than frequent stimuli. In average responses the ERGBO to rare stimuli followed P300, beginning at 440.5 ms and continuing for about 100 ms. Past studies suggest P300 ERP component reflects a role in cognitive function. Since ERGBO in the present study appeared in different regions and at a different latency from P300, ERGBO may reflect a different physiological role in the cognitive process.     

Mental rotation differences between Chinese characters and English letters

We investigated mental rotation and rotational uncertainty effect of Chinese characters and English letters, respectively by event-related potential (ERP) and behavior responses. The results indicated that subjects could mentally rotate Chinese characters and English letters at similar speed, but the total response time (RT) for Chinese characters was significantly longer. Rotational uncertainty effect was more prominent for Chinese characters than English letters in both behavior results and the amplitudes of P300 component. With the increase of orientation angle, the left-hemispheric dominance of P300 component was observed for English letters at parietal area, while Chinese characters did not show evident hemispheric asymmetry. Our results implied that significant difference of RT and ERP between different stimulus types is supposed to be in the sub-stages of the stimulus perceptual encoding and/or parity judgment.     

糖尿病脑病患者认知功能障碍的神经电生理学研究

目的 研究糖尿病脑病患者事件相关电位(ERP)的特征及早期评定患者有无认知功能障碍及严重程度的临床价值.方法 对39例糖尿病脑痛(DM&ICVD)患者、32例缺血性脑血管病(ICVD)患者及24例正常人进行事件相关电位检查及简易智能量表(MMSE)检测,将两组检测结果与正常对照组比较.结果 DM&ICVD组、ICVD组...     

Quality of sleep and P300 amplitude in primary insomnia: a preliminary study

STUDY OBJECTIVE: The aim of this study is to evaluate whether the cortical arousal level in subjects with primary insomnia varies according to their quality of nighttime sleep. DESIGN: The P300 ERP was recorded each day, before and after sleep actigraphically monitored for 1 week. For each participant, the nights of worst- and best-quality sleep were identified. PARTICIPANTS: Seven subjects with primary insomnia and 7 control subjects. MEASUREMENTS AND RESULTS: The P300 amplitudes were compared by considering group (insomnia vs control), night (worst vs best), and moment of recording (before vs after sleep) as factors. The subjects with insomnia showed higher P300 amplitudes, as compared with amplitudes of control subjects, only for the worst night of sleep. CONCLUSIONS: Results indicate a relationship between variations in sleep quality and cortical arousal level in subjects with primary insomnia.     

Event-related potential in patients with diabetes mellitus]

The event-related potential (ERP) was recorded for 24 patients with diabetes mellitus (age 67.5 +/- 8.5 years, mean +/- SD) and 28 healthy controls (age 61.0 +/- 10.6 years) to elucidate the involvement of the central nervous system (CNS) in diabetes mellitus. ERP was recorded during auditory discriminative tasks. The latencies of N100, P200, N200 and P300 from the Pz region were measured. Patients with diabetes mellitus showed significant prolongation of N200 and P300 latencies compared with the normal subjects, while no significant differences in N100 and P200 latencies were found between the two groups. In six of 24 patients, the P300 latency delayed beyond the 2SD of the appropriate age-related value estimated from the normal regression line. The delay of the P300 latency was not related to either the duration of illness, therapeutic methods, or metabolic control. From the present results, it would appear that higher brain function is impaired even in diabetic patients not manifesting overt CNS signs and symptoms.     

Auditory event related potentials relate with the clinical progression in idiopathic generalized epilepsy

Auditory event related potential (ERP) was studied in 60 patients with idiopathic generalized epilepsy and 33 age and sex matched healthy subjects. Thirty nine patients came to the control three months later and were reassessed. All auditory evoked potential latencies were prolonged in epileptics compared to those of healthy subjects. Multiple drug using or history of more than 100 seizures was associated with prolonged P3 latency. History of status epilepticus was observed together with prolongation of N2 and P3 latencies. Patients using their antiepileptic drugs more properly after the first control showed shortened P3 latency in the second control.     

癫患者的事件相关电位与认知功能研究

目的 :探讨癫患者事件相关电位 (ERP)与认知功能状况。方法 :对 35 0例癫患者和15 0例正常对照组进行认知功能 30题 (CCSE)、简易智力状态试验 (MMSE)和ERPP30 0 的测定。结果 :癫部分性发作者的P30 0 潜伏期比全身性发作者明显延长 ,波幅降低显著 ,认知功能测试得分也较低 ;未能分类发作患者的P30 0 潜伏期延长不明显 ,认知功能测试得分近于正常。病程 >5年者的P30 0 潜伏期较病程 1～ 5年的延长明显 ,波幅降低显著 ,认知功能测试得分也较低 ;病程 <1年者P30 0 潜伏期延长不明显 ,认知功能测试得分在正常范围。同时用三种药者的P30 0 潜伏期较同时用两种药者的延长明显 ,波幅降低显著 ,认知功能测试得分也较低 ;同时用两种药者的P30 0 潜伏期也比用一种药者明显延长 ,认知功能测试得分也较低 ;用一种药者的P30 0 潜伏期延长不明显 ,认知功能测试得分在正常范围。结论 :部分性发作患者的P30 0 潜伏期延长较全身性发作者明显 ;病程越长 ,P30 0 潜伏期延长越显著 ;多种用药患者的P30 0 潜伏期延长较用一种药者显著。     

MBP、IL-16在Guillain—Barré综合征发病中的机制

目的探讨髓鞘碱性蛋白（MBP）和白细胞介素16（IL-16）在Guillain-Barré综合征（GBS）发病过程中的变化。方法用ELISA法检测GBS组（36例）中MBP和IL-16的水平，并与多发性硬化（MS）组（45例）及对照组（33例）相比较。结果GBS、MS和对照组3组中CSFMBP的水平均明显高于Serum MBP的水平（P〈0．01），而CSF IL-16的水平均明显低于Serum IL-16的水平（P〈0．01）。GBS组CSF中MBP的水平明显高于对照组（P〈0．01）但低于MS组（P〈0．01），Serum中MBP水平和对照组相比无明显差异但低于MS组（P〈0．01）。CSF中的IL-16水平明显高于对照组（P〈0．05），但与MS组相比无明显差异，Serum中IL-16的水平低于对照组（P〈0．01）但与MS组相比无明显差异。结论GBS发病早期神经根髓鞘的脱失可能更严重，中枢神经系统局部产生的IL-16参与了GBS神经根脱髓鞘的炎症过程。     

Auditory and Visual P300s in Temporal Lobectomy Patients: Evidence for Modality-Dependent Generators

The P300 component of the event-related brain potential (ERP) was studied in epileptic patients with unilateral resections of medial temporal lobe areas of the brain. The patients and controls were tested in an oddball paradigm in two conditions: counting and reaction time. Both auditory and visual stimuli were used to elicit ERP activity in different blocks. Despite the reported presence of locally-generated auditory and visual P300-like potentials in these areas, no evidence was found of any surgically-related hemispheric asymmetries in the scalp distribution of the P300 or Slow Wave for stimuli in either modality. Moreover, compared to normal controls, there were no significant reductions in overall P300 amplitude in the patients. The patients did show a double dissociation in their frontal ERP activity: the left temporal lobectomy patients showed apparent decreased frontal auditory P300 amplitudes but normal visual P300 amplitudes, whereas the right temporal lobectomy patients showed the opposite pattern. These results appeared to be due to the presence of a long-duration slow wave rather than to alterations in P300 amplitude. These data do not support the presence of a significant contribution by a hippocampal/amygdala generator to the activity of the scalp-recorded P300 in the oddball paradigm. Topographic comparisons on normalized amplitudes revealed significantly different scalp distributions as a function of stimulus modality, event probability, and task for both the P300 and Slow Wave components. These data indicate that the amplitude variations associated with each experimental variable are due to the activity of a separate underlying neural source. The sources of task and probability effects on P300 and Slow Wave amplitude each appeared to be modality-independent generators. The nature of the third, modality-related generator is less clear. These results uphold the tenets of the model of P300 amplitude proposed by Johnson (1986) and argue against the idea that the P300 is a unitary phenomenon.     

P300, probability, and introverted/extroverted personality types.

Extreme introverted and extroverted subject groups (n = 24 each) containing equal numbers of male and females were assessed with the P300 (P3) component of the event-related potential (ERP). A two-tone auditory discrimination task in which the probability of the target stimulus varied systematically in different conditions (.20, .40, .60, .80) was used to elicit the ERPs. The P3 amplitude demonstrated a significant interaction between personality type, probability, and subject gender and was generally smaller for introverts than for extroverts. Female subjects tended to have larger overall P3 components than male subjects. P3 latency was not affected by the personality variable. The results support previous findings for ERP differences between introverts and extroverts and suggest that personality type differentially influences target stimulus probability effects. The findings are discussed in terms of individual differences in cortical activity on P3 amplitude and personality measures.