Cognition in epilepsy: a multichannel event related potential (P300) study

Auditory event-related potentials (AERP) were elicited in 68 epileptic patients and 30 age-matched controls. Epileptic patients had significantly prolonged N2 and P300 (P3) latencies compared with controls. Seven patients were above the range of 3 standard deviations from the control mean values. Amongst epileptics, patients with temporal lobe epilepsy had significantly prolonged P3 latencies compared to patients with idiopathic generalized epilepsy. Patients with abnormal EEGs had significantly prolonged P3 latencies compared to those with normal EEGs. Patients on anticonvulsant monotherapy had shorter P3 latencies, compared to patients taking a combination of two or more anticonvulsants. Patients on shorter duration of treatment had less prolonged P3 latencies compared to those on longer anticonvulsant treatment.     

酒精所致精神障碍患者事件诱发电位P300的研究

目的：探讨酒精所致精神障碍患者事件诱发电位P300的特点。方法：对30例酒精所致精神障碍患者（研究组）和31名正常人（正常对照组）进行事件诱发电位P300的检测,并与正常对照组进行配对t检验和相关分析。结果：与正常对照组比较,酒精所致精神障碍患者P300潜伏期N2、P3显著延长（t=2．318,沁2．335;P〈0．05）;P300波幅N1、N2、P3显著降低（t=-2．414;t=-2．613,t=-4．453;P〈0．05或P〈0．001）。相关分析显示,酒精所致精神障碍患者饮酒年限以及饮酒量与P300潜伏期、波幅之间无明显相关（r=-0．128～-0．274,r=-0．075～0．328;P均〉0．05）。结论：酒精所致精神障碍患者存在认知功能损害,P300可作为酒精所致精神障碍患者检测项目之一。     

Changes in auditory P300 event-related potentials and brainstem evoked potentials in diabetes mellitus

To investigate the influence of diabetes mellitus on higher cognitive functions electrophysiologically, we studied auditory P300 event-related potentials (P300) in 40 NIDDM patients, taking into account wave I-V latencies (I-V) in auditory brainstem evoked potentials, clinical parameters and head MRI findings. Compared with 20 controls, diabetics had significantly longer P300 and I-V latencies. P300 latencies in diabetics correlated with neither I-V. HbA₁, blood glucose levels, nor disease duration. Of the 13 diabetics investigated neuroradiologically, four had lacunar infarcts with prolonged electrophysiological values. The remaining nine had normal MRI scans, but their physiological parameters were still significantly longer than those of controls. These findings suggest that NIDDM can independently alter higher cognitive and the central auditory pathway functions. Our data also suggest that these alterations occur regardless of the recent metabolic derangement and disease duration. Cerebrovascular ischemia, if present, also appears to contribute in part to cognitive alterations.     

Event-related potentials (P300) in myotonic dystrophy

The P300 component of the auditory event-related potential in 8 patients with myotonic dystrophy was studied and compared with that of 13 healthy controls. Abnormalities of P300 (prolongation of the latency and/or decrease of the amplitude) were observed in 6. These observations imply that the function of cognitive and information processing are impaired in myotonic dystrophy.     

老年期抑郁症患者事件相关电位P300特征

目的：探讨有无自杀行为的老年期抑郁症患者认知功能的事件相关电位P300特征。方法：对60例老年期抑郁症患者（有自杀行为者20例,无自杀行为者40例）及60例性别、年龄匹配的正常老年人为对照,进行听觉诱发的事件相关电位P300检测。同时应用汉密尔顿抑郁量表（HAND）及老年认知功能量表（SECF）分别评价抑郁症组抑郁情绪及认知功能。结果：抑郁症组与对照组相比,P2、N2、P3潜伏期明显延长,P2、P3波幅明显降低;有自杀行为组N2、P3波幅比无自杀行为组明显降低。抑郁症组HAMD总分与P300各指标无相关,SECF总分与N2、P2、P3潜伏期显著负相关。结论：P300对老年期抑郁症患者早期认知功能损害评定具有一定价值,有、无自杀行为的老年期抑郁症患者认知功能损害不同。     

酒精所致精神障碍患者的P300、智能损害及相关因素研究

目的:探讨酒精所致精神障碍患者的P300、智能损害及相关因素。方法:对顺序住院30例酒精所致精神障碍患者和30名健康者分别进行P300和韦氏智力测试,比较测试结果并对影响因素进行分析。结果:研究组P300潜伏期(374.90±63.08)ms长于对照组(305.40±10.84)ms,差异有显著性(P=0.000)。研究组波幅(5.62±2.42)μV低于对照组(7.50±0.76)μV,差异有显著性(P=0.000)。研究组语言智商、操作智商、总智商分别为(85.60±10.82)分、(86.60±12.59)分、(82.27±11.52)分,低于对照组分别为(103.30±3.40)分、(99.90±2.74)分、(101.16±2.57)分,差异有显著性(P=0.000)。偏相关分析:控制平均日饮酒量因素P300潜伏期与酒依赖病程相关(r=0.577,P=0.001)。总智商与酒依赖病程相关(r=-0.582,P=0.001)。结论:酒精所致精神障碍患者的P300潜伏期明显延长,波幅明显降低,智力明显下降,认知损害明显。认知损害程度主要与酒依赖病程有关。     

额叶肿瘤患者认知功能和事件相关电位P300的研究

目的 探讨额叶肿瘤患者认知功能的损害和事件相关电位P300有关参数的变化特点,了解额叶在认知功能及P300产生中的作用.方法 对31例额叶肿瘤患者(左侧15例、右侧16例)及30例健康对照者分别进行Stroop字色干扰等多项认知神经心理学测试和P300检查.结果 与健康对照组相比,额叶肿瘤组认知功能各项测试指标评分均显著降低(P＜0.05),P300的N2、P3波潜伏期显著延长(P＜0.05),P3波幅显著降低(P＜0.05).进一步研究发现,右额叶肿瘤组患者的各项认知测试指标评分均显著低于健康对照组(P＜0.05),而左额叶肿瘤组只有词语流畅性指标评分显著低于健康对照组(P＜0.05);与健康对照组相比,左、右额叶肿瘤组P300的N2、P3波潜伏期均显著延长(P＜0.05),P3波幅均显著降低(P＜0.05);左、右额叶肿瘤组患者之间的P300比较则无统计学差异(p＞0.05).结论 额叶肿瘤患者认知功能有明显损害,右侧肿瘤患者的认知功能损害更严重:额叶可能与P300发生或传导有关,且左右额叶无明显的差异.     

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.     

注意缺陷多动障碍儿童事件相关电位P300特征分析

目的:探讨注意缺陷多动障碍(ADHD)儿童事件相关电位(event related potential,ERP)P300的特点。方法:对100例ADHD患儿(研究组)[注意缺陷为主型(ADHD-I)34例、多动/冲动为主型(ADHD-HI)24例、混合型(ADHD-C)42例)]和100名正常儿童(对照组)前额区(Fz)、中央区(Cz)两个脑区的ERP P300潜伏期及波幅进行检测,比较分析研究组与对照组、ADHD各亚型及不同SNAP-Ⅳ评分分组(1.6~2.0为中度组、2.0为重度组)的P300潜伏期及波幅的差异。结果:1与对照组比较,研究组靶刺激在前额区(Fz)及中央区(Cz)P300潜伏期显著延长,波幅降低,差异具有统计学意义(P均0.01);2ADHD各亚型组间P300潜伏期与波幅差异无统计学意义(P0.05);3不同SNAP-IV评分组间,P300潜伏期与波幅差异无统计学意义(P0.05)。结论:ADHD患儿P300的潜伏期显著延长,波幅降低,提示ADHD患儿对信息加工处理的速度减慢,注意力、记忆力缺陷及认知加工能力不足。     

Evaluating sub-clinical cognitive dysfunction and event-related potentials (P300) in clinically isolated syndrome

Objective  This study investigated the presence of sub-clinical cognitive dysfunction in patients with clinically isolated syndrome (CIS) and the abnormalities of cognitive event-related potentials (ERPs). Methods  Subclinical cognitive dysfunction was assessed in 20 patients with CIS and in 20 healthy controls. Results  Patients had impairments in verbal learning and long-term memory, evaluating attention, executive function and visuospatial skills, in decreasing order of frequency. SDLT and SIT were the most, and COWAT and BNT were the least affected tests. The N200 and P200 latencies were prolonged, and N100, N200 and P200 amplitudes were reduced in the patients relative to the controls, from the Fz, Cz and Pz electrode positions (p<0.05). Conclusion  Detailed cognitive testing is valuable in determining subclinical cognitive dysfunction in CIS patients. ERP abnormalities as well as abnormalities in detailed cognitivetesting in patients with CIS are helpful in the diagnosis of sub-clinical cognitive dysfunction.     

Distinct neurophysiological mechanisms for manic and cycloid psychoses: evidence from a P300 study on manic patients

Pathologically asymmetrical P300 fields with right lateralized peaks were described in core schizophrenia as an expression of left-temporal functional deficits, while higher than normal amplitudes were found in cycloid psychosis. This latter finding appeared to be specific for cycloid psychosis and was explained by a generalized cerebral hyperarousal. Based on some psychopathological analogies with cycloid psychosis, and on the comparable pharmacological treatment of the acute episodes, a group of 19 manic patients was investigated immediately after remission and clinical stabilization of an episode. Patients with psychotic features were excluded to avoid overlaps with cycloid psychosis. Patients showed normal P300 amplitudes and no pathological asymmetries of the field, but more posterior positive areas compared to age- and sex-matched controls. This indicates that the neurophysiological changes underlying mania are different from both core schizophrenia and cycloid psychosis. Based on previous three-dimensional source location studies, this finding indicates that disinhibition due to reduced frontal lobe activity, and not hyperarousal, is the basic functional mechanism of manic disorders.     

强迫症患者听觉事件相关电位P300的研究

目的 探讨听觉事件相关电位（ERP） P300与强迫症患者各项指标的相关性.方法 将63例强迫症患者作为研究组,选取63名身心健康正常人为对照组,采用自制的一般状况调查表了解两组人员的基本情况,对两组人员分别进行事件相关电位P300的检测,对强迫症患者采用耶鲁布朗强迫症量表评估其病情.结果 研究组ERP各项指标中N2、P3潜伏期长于对照组（t分别为-1.568,-2.602;P＜0.05）,N1、P2、N2、P3波幅均小于对照组（t分别为2.505,2.646,3.029,4.904;P＜0.05）.强迫思维组N2、P3潜伏期长于强迫行为组（t分别为3.301,2.580;P＜0.05）,P3波幅低于强迫行为组（t=-5.240,P＜0.01）.经相关分析显示事件相关电位P300的P3波幅与强迫思维分及强迫行为分呈负相关（r分别为-0.384,-0.512;P＜0.05）,N2和P3潜伏期均与强迫思维分呈正相关（r分别为0.448,0.405;P＜0.05）.结论 听觉事件相关电位P300可以客观反映强迫症的认知功能.     

The P300 event-related brain potential as a neurobiological endophenotype for substance use disorders: a meta-analytic investigation

Endophenotypes are intermediate phenotypes on the putative causal pathway from genotype to phenotype and can aid in discovering the genetic etiology of a disorder. There are currently very few suitable endophenotypes available for substance use disorders (SUD). The amplitude of the P300 event-related brain potential is a possible candidate. The present study determined whether the P300 amplitude fulfils two fundamental criteria for an endophenotype: (1) an association with the disorder (disease marker), and (2) presence in unaffected biological relatives of those who have the disorder (vulnerability marker). For this purpose, two separate meta-analyses were performed. Meta-analysis 1 investigated the P300 amplitude in relation to SUD in 39 studies and Meta-analysis 2 investigated P300 amplitude in relation to a family history (FH+) of SUD in 35 studies. The findings indicate that a reduced P300 amplitude is significantly associated with SUD (d = 0.51) and, though to a lesser extent, with a FH+ of SUD (d = 0.28). As a disease maker, the association between reduced P300 amplitude and SUD is significantly larger for participants that were exclusively recruited from treatment facilities (d = 0.67) than by other methods (i.e., community samples and family studies; d = 0.45 and 0.32, respectively), and larger for abstinent SUD patients (d = 0.71) than for current substance users (d = 0.37). Furthermore, in contrast to FH+ males, a P300 amplitude reduction seems not to be present in FH+ females (d = −0.07). Taken together, these results suggest that P300 amplitude reduction can be both a useful disease and vulnerability marker and is a promising neurobiological endophenotype for SUD, though only in males. Implications and future directions are discussed.     

Auditory P300 event-related potential in tobacco smokers

The aim of this study was to elucidate the chronic effects of tobacco smoking on the P300, a neurophysiological index of cognitive function. Prospective study participants were recruited from a family medicine polyclinic. We selected 32 right-handed smokers who had smoked more than 15 cigarettes per day, by inhalation, for more than 2 years. The control population consisted of 32 right-handed, age-matched healthy individuals who had never smoked. Event-related potentials (ERPs) were recorded with the auditory “oddball” two-tone discrimination task. The data from the central (Cz) and frontal (Fz) electrodes were analyzed. The P300 and N1 amplitudes at Fz were lower in the study population compared to the control group. The early component of ERP, the measure of mental speed (N1) latency at Fz was prolonged in the study group compared to the controls, possibly because early cognitive processes such as sensory input or initial encoding of sensory information were delayed in this group. For those who smoke, a decreased N1 amplitude might indicate delayed information processing and possibly short-term memory disturbance. Thus, chronic tobacco smoking may produce prefrontal cognitive dysfunction.     

内侧颞叶在P300产生中的作用--左颞叶切除术后1例患者的事件相关电位研究

目的探讨内侧颞叶(MTL)在P300产生中的作用。方法对1例左颞叶切除的患者和17名健康对照者进行视、听两种模式下的P300研究。结果患者的视、听P300潜伏期(PL)、波幅(Amp)和侧性分布均在对照组确定的正常范围之内。结论一侧MTL结构切除并不影响事件相关电位的内源性成分P300，P300的产生可能是脑多个部位共同活动的电位综合。     

Brainstem auditory evoked potentials in the diagnosis of multiple sclerosis

Brainstem auditory evoked potentials (BAEPs) have been investigated in 34 patients affected by Multiple Sclerosis. Abnormalities were found in 68% of the patients. Silent lesions of the brainstem were detected in 60% of the clinically definite and in 44% of the probable cases. The diagnostic value of these findings is discussed.

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Sommario I potenziali evocati uditivi sono stati investigati in 34 pazienti affetti da sclerosi multipla. Anormalità sono state evidenziate nel 68% dei pazienti affetti da sclerosi multipla clinicamente definita. Lesioni silenti del brainstem sono state trovate nel 60% delle forme clinicamente definite e nel 44% di quelle probabili. Il valore diagnostico di questi reperti è discusso.

     

老年期焦虑抑郁患者事件相关电位P300特征

目的：探讨老年期焦虑抑郁共病患者认知功能的事件相关电位P300特征。方法：对60例老年抑郁症患者（以伴有焦虑者为共病组25例,单纯抑郁症者为抑郁症组35例）及60名性别、年龄匹配的正常老年人（对照组）进行听觉诱发的事件相关电位P300检测。同时应用汉密尔顿抑郁量表（HAMD）、汉密尔顿焦虑量表（HAMA）及老年认知功能量表（SECF）分别评价患者组抑郁、焦虑情绪及认知功能。结果：患者组P2、N2、P3潜伏期及反应时间比对照组明显延长,P2、P3波幅明显降低;共病组N2、P3波幅比抑郁症组明显降低,P3潜伏期明显延长。患者组HAMD、HAMA总分与P300各指标无相关,而SECF总分与N2、P2、P3潜伏期呈显著负相关。结论：P300对老年期抑郁症早期认知功能损害评定具有一定的价值,共病组患者认知功能损害程度大于抑郁症组。     

Erectile impotence in multiple sclerosis: a neurophysiological study

Pudendal evoked potentials, motor evoked potentials of the bulbocavernosus muscle to magnetic stimulation and bulbocavernosus reflex were recorded in 34 patients with multiple sclerosis (MS). Responses were delayed in 26, 20 and 3 cases respectively. No relationship was found between neurophysiological abnormalities and the presence or severity of erectile dysfunction, showing that these tests have little diagnostic usefulness in MS patients with impotence. Nocturnal penile tumescence was assessed in 14 cases: the test result was normal in 10 patients, including 3 severely paraplegic subjects.     

精神分裂症患者事件相关电位相关性研究

目的：探讨精神分裂症患者事件相关电位P300的特点及事件相关电位与阴性、阳性症状的相关性。方法：对28例精神分裂症患者及21名健康志愿者进行事件相关电位P300的检测。结果：两组靶刺激时P300的N2、P3潜伏期和P2、P3波幅有显著差异。结论：提示事件相关电位P300在协助精神分裂症的诊断、分型及推测预后方面有一定意义。     

Limbic P300s in temporal lobe epilepsy with and without Ammon's horn sclerosis.

Limbic P300 potentials can be recorded within the mesial temporal lobes of patients with temporal lobe epilepsy (TLE). To delineate possible mechanisms of their generation and pathological alteration, we analysed limbic P300s in 55 TLE patients with and 29 without Ammon's horn sclerosis (AHS) and correlated their amplitudes with neuronal cell counts in 30 histopathological specimens. Limbic P300 amplitudes were reduced on the side of the epileptogenic focus only in patients with AHS. Moreover, in AHS patients, limbic P300 latencies were prolonged bilaterally; and in patients with left-sided AHS, amplitudes were reduced bilaterally. Both findings suggest bilateral functional deficits in TLE with unilateral AHS. Limbic P300 areas correlated significantly with neuronal densities of dentate gyrus granule cells but not hippocampal pyramidal cells in the CA1-4 (cornu ammonis) subfields. This finding points to a potential mechanism for the bilateral effects of unilateral AHS as both dentate gyri exhibit strong reciprocal contralateral connectivity.