Auditory and visual P300 reflecting cognitive improvement in patients with schizophrenia with quetiapine: A pilot study

We recorded event-related potentials (ERPs) in patients with schizophrenia before and after treatment with quetiapine, to investigate this drug's effects on cognitive function. Auditory and visual oddball stimulus discrimination paradigms were presented to patients with schizophrenia (N = 20) before and after 3 months' treatment with quetiapine. The 2-stimulus auditory oddball paradigm used a standard tone (1000 Hz, 75 dB, 80%) and a target tone (2000 Hz, 75 dB, 20%). The 2-stimulus visual oddball paradigm used a standard stimulus (small circle, 80%) and a target stimulus (large circle, 20%). Patients' severity of psychopathology was initially evaluated with the Positive and Negative Syndrome Scale (PANSS) and was likewise re-evaluated after treatment. After treatment with quetiapine, patients' P300 amplitudes increased over baseline for both tasks (auditory stimuli, P < 0.01; visual stimuli, P < 0.01) and their P300 latencies for both target stimuli decreased significantly (auditory stimuli, P < 0.001; visual stimuli, P < 0.01). Visual P300 amplitude was negatively correlated with the severity of positive symptoms at the Fz electrode before the treatment (r = − 0.45, P < 0.05). After treatment with quetiapine, there were no significant correlations between severity of positive or negative symptoms and visual P300 amplitudes for midline electrodes. These findings suggest that the reduced and delayed P300 may be a state marker for schizophrenia, which may in turn be modulated by positive symptoms, and also suggest that the amplitude and latency for both auditory and visual tasks may be decreased by quetiapine treatment. Based on these results, we suggest that the atypical antipsychotic quetiapine may improve some aspects of cognitive domains in patients with schizophrenia.     

Auditory evoked cortical responses to frequency glides in subjects with retrocochlear hearing impairment.

Auditory cortical responses evoked by stimulation with frequency glides of a continuous tone have been recorded from 44 subjects with intracranial tumours affecting auditory function. Response latencies obtained when stimulating the ear on the side of the tumour were different from the non-tumour ear as well as from groups with cochlear impairment and normal hearing. Tumours caused a reduction of a specific sensitivity to the frequency glide stimulation, affecting further processing of the dynamic change in tone frequency. The test appears to have diagnostic potential.     

Auditory and visual P300 evoked potentials do not predict response to valproate treatment of aggression in patients with borderline and antisocial personality disorders.

In this study of patients with borderline personality disorder (BPD) or antisocial personality disorder (ASPD) hospitalized because of aggressive behavior, auditory and visual P300 evoked potentials were obtained prior to treatment with valproate. Eight ASPD patients (8 males, 0 females) and 11 BPD patients (2 males, 9 females) showed improvement, while in 7 patients with ASPD (7 males, 0 females) and 10 patients with BPD (2 males, 8 females), aggression was not improved. Differences in auditory and visual P300 latencies and amplitudes were not significant for either diagnosis, or for both diagnoses combined. These findings suggest that auditory or visual P300 evoked potentials may not be useful for predicting response of aggressive behavior to valproate treatment in patients with BPD or ASPD.     

The effects of donepezil on the P300 auditory and visual cognitive evoked potentials of patients with Alzheimer's disease.

Donepezil is a cholinesterase inhibitor used for the treatment of patients with mild to moderately severe Alzheimer's disease (AD). The purpose of this study was to determine the effect of treatment with donepezil 5 mg qd on cognitive evoked potentials (EPs) of patients with AD. Although treatment with donepezil did not normalize EP latencies, treatment was associated with a significant decrease in the auditory P300 latency (mean latency pretreatment=401. 5 msec; posttreatment=392.7 msec.; P=0.04), and the visual P300 latency (mean latency pretreatment=605.7 msec; posttreatment=580.3 msec; P=0.04). Treatment with donepezil had no discernible effect on auditory or visual P300 EP amplitudes.     

双相障碍抑郁发作患者认知功能损害及与听觉P300改变的关系

目的:探讨双相障碍抑郁发作患者认知功能损害和听觉P300变化的关系.方法:采用重复性神经心理状态测验(RBANS)及听觉诱发电位检测方法对43例首次发病未服药的双相障碍抑郁发作患者(病例组)及45名健康志愿者(对照组)进行认知功能及P300指标检测;结果 进行组间比较和分析.采用汉密尔顿抑郁量表(HAMD)评估病例组患...     

康复期男性海洛因依赖患者认知功能与视觉诱发电位P300的关系

目的 探讨康复期男性海洛因依赖患者(MPHD)神经心理学测验成绩与视觉诱发电位P300(VEP-P300)的关系.方法 采用韦氏记忆量表(WMS)、威斯康星卡片分类测验一改良版(M-WCST),对38例康复期MPHD(MPHD组)及14名健康对照(对照组)进行神经心理学评估,并于1周内检测受试者前额区(Fz)、中央区(Cz)及顶区(Pz)的VEP-P300.结果 (1)M-WCST评分:MPHD组卡片分类正确数、正确分类数、随机错误数均少于对照组(P＜0.01),错误数和持续错误数多于对照组(均P＜0.01).(2)WMS评分:除数字顺序累加因子,MPHD组的记忆商数(MQ)及各因子分均低于对照组(P＜0.05～P＜0.01).(3)VEP-P300检测:MPHD组与对照组各指标的差异无统计学意义(P＞0.05).(4)Pearson相关分析:在Fz点,波幅与WMS数字顺序1-100呈正相关(r=0.321),潜伏期与数字顺序1-100(r=-0.325)、图片回忆呈负相关(r=-0.449),均P＜0.05～0.01.在Cz点,潜伏期与M-WCST分类正确数(r=-0.388)、数字顺序1-100(r=-0.386)呈负相关,与分类错误总数呈正相关(r=0.388),均P＜0.05.在Pz点,波幅与数字顺序1-100(r=0.357)、数字顺序100-1(r=0.374)、触觉记忆(r=0.370)、MQ(r=0.322)呈正相关,均P＜0.05;潜伏期与M-WCST分类正确数(r=-0.377)、图片回忆(r=-0.364)呈负相关,与M-WCST分类错误总数呈正相关(r=0.377),均P＜0.05.结论 康复期的MPHD仍存在明显的认知功能损害,VEP-P300与神经心理学测验成绩存在较为密切的关系.     

Auditory brain-stem, middle- and long-latency evoked potentials in mild cognitive impairment.

OBJECTIVE: Mild cognitive impairment (MCI) is a selective episodic memory deficit in the elderly with a high risk of Alzheimer's disease. The amplitudes of a long-latency auditory evoked potential (P50) are larger in MCI compared to age-matched controls. We tested whether increased P50 amplitudes in MCI were accompanied by changes of middle-latency potentials occurring around 50 ms and/or auditory brain-stem potentials. METHODS: Auditory evoked potentials were recorded from age-matched controls (n = 16) and MCI (n = 17) in a passive listening paradigm at two stimulus presentation rates (2/s, 1/1.5 s). A subset of subjects also received stimuli at a rate of 1/3 s. RESULTS: Relative to controls, MCI subjects had larger long-latency P50 amplitudes at all stimulus rates. Significant group differences in N100 amplitude were dependent on stimulus rate. Amplitudes of the middle-latency components (Pa, Nb, P1 peaking at approximately 30, 40, and 50 ms, respectively) did not differ between groups, but a slow wave between 30 and 49 ms on which the middle-latency components arose was significantly increased in MCI. ABR Wave V latency and amplitude did not differ significantly between groups. CONCLUSIONS: The increase of long-latency P50 amplitudes in MCI reflects changes of a middle-latency slow wave, but not of transient middle-latency components. There was no evidence of group difference at the brain-stem level. SIGNIFICANCE: Increased slow wave occurring as early as 50 ms may reflect neurophysiological consequences of neuropathology in MCI.     

轻度认知损害老年患者脑干听觉反应、P300及脑电图的研究

目的 探讨轻度认知损害(MCI)患者的脑干听觉反应(BAEP)、事件相关电位(ERP)P300和脑电图(EEG)的特点,为早期痴呆的诊断提供帮助。方法 对38例MCI患者(MCI组)、26例阿尔茨海默病(AD)患者(AD组)进行BAEP和P300、EEC检查,并与20名健康老年人(健康组)作比较。结果 BAEP检查:MCI组与AD组左侧Ⅰ、Ⅱ波的差异均有显著性,P<0.05;MCI组与健康组比较,左、右侧Ⅳ、Ⅴ波的差异有显著性,P<0.05;AD组与健康组比较,左侧Ⅰ-Ⅳ波及右侧Ⅳ、Ⅴ波的差异均有非常显著性(P<0.01),右侧Ⅰ波差异有显著性(P<0.05)。P300检查,MCI组与AD组只在潜伏期的Pz点差异有显著性(P<0.05);MCI组与健康组在潜伏期Cz点差异有显著性(P<0.05);AD组与健康组比较,潜伏期的Fz、Cz、Pz点差异均有非常显著性(P<0.01),波幅的Cz点差异有显著性(P<0.05)。EEG显示,MCI组未见明显异常的18例,轻度异常17例,中度异常3例;AD组未见明显异常的1例,轻度异常8例,轻-中度异常9例,中度异常8例。结论 P300潜伏期的Pz点的改变可能有助于区分MCI和AD,而右侧Ⅳ、Ⅴ波的延长提示MCI患者可能有早期痴呆;EEG左侧颞部θ波增多提示MCI患者可能有早期AD。     

Provoked visual impairment in multiple sclerosis studied by visual evoked responses.

Pattern-reversal VERs were studied during the visual impairment provoked by exercise in 2 patients with demyelinating optic neuritis. It was found that the transient reduction in visual acuity was correlated to a transient decrease in the amplitude of the major positive component of the VER, whereas no significant changes could be observed in the latency of the response. The normal VER was not influenced by exercise.     

Auditory and visual P300 topography from a 3 stimulus paradigm.

OBJECTIVE: The P300 event-related brain potential (ERP) was elicited with auditory and visual stimuli in a separate session of a 3 stimulus oddball paradigm, and the scalp topography was assessed with 15 electrode locations. METHODS: Target (0.10), standard (0.80), and infrequent non-target (0.10) stimuli in the auditory task were 2000, 1000 and 500 Hz tone, and in the visual task, 'X', 'O', and 'H', respectively. The stimuli were presented in a random series, once every 2 s, and participants responded only to the target (N = 12). RESULTS: Target stimuli elicited larger P300 components than non-target did in both stimulus modalities. For both target and non-target stimuli, P300 amplitude was larger and latency longer for the visual compared with the auditory stimulus. Analysis of normalized P300 amplitude data indicated that the target and non-target P300s from both modalities had identical topography. CONCLUSION: The findings suggest that both target and non-target stimuli in 3 stimulus oddball paradigm elicited the same type of P300 (P3b) for both stimulus modalities.     

Auditory event-related potentials (P300) in epileptic patients.

Auditory event-related potentials (AERPs) were recorded during an auditory oddball paradigm in 108 epileptics and in 32 healthy controls. P300 latency varied in relationship with age only in controls. Symptomatic epileptics had significantly prolonged P300 mean latency compared to those without detectable brain lesion(s) on MR scan. Moreover, these latter patients were compared on the basis of epilepsy duration, type of seizure, seizure frequency and antiepileptic treatment; the application of a multiple regression model showed a significant relationship between P300 latency prolongation and epilepsy duration, seizure frequency and polytherapy.     

氟伏沙明与阿米替林改善抑郁症认知损害的P300对照研究

目的比较氟伏沙明与阿米替林对抑郁症患者认知功能的影响。方法将60例符合《中国精神障碍分类与诊断标准——第3版》（CCMD-3）抑郁症诊断标准患者作为实验组,与实验组性别、年龄匹配的30例健康人作为对照组。随机将实验组分为氟伏沙明治疗组（实验组1,n=30）及阿米替林组（实验组2,n=30）,治疗8周前后予P300检测及汉密顿抑郁量表（HAMD）评定,比较各组P300各成分及HAMD评分的差异。结果与对照组相比,治疗前实验组1及实验组2P2、N2、P3潜伏期及反应时间明显延长,P2、N2、P3波幅明显降低,差异具有显著性意义（P〈0．05或P〈0．01）;治疗后,实验组1P2、N2、P3潜伏期及反应时间比治疗前明显缩短,P2、N2、P3波幅明显增高,差异有显著性意义（P〈0．05或P〈o．01）;实验组2P2、N2、P3潜伏期及反应时间比治疗前明显降低（P〈0．05或P〈0．01）,但P2、N2、P3波幅与治疗前比较差异无显著性意义（P〉0．05）。结论抑郁症患者存在认知功能障碍,氟伏沙明具有明显改善抑郁症认知功能的作用。     

Auditory P300 in patients with bipolar disorder and their unaffected relatives

Objectives: There is evidence that genetic susceptibility may be shared between bipolar disorder (BD) and schizophrenia, but electrophysiological phenotypes which have been extensively used in studies of genetic susceptibility for schizophrenia remain far less explored in bipolar illness. This study assesses whether auditory P300 latency delays and amplitude reductions, which have been demonstrated in patients with schizophrenia and their unaffected first‐degree relatives, are associated with familial liability to psychotic bipolar illness. Methods: The P300 auditory evoked potential was obtained using an oddball task from 37 participants with BD who had a history of psychotic symptoms, 38 of their unaffected first‐degree relatives and 42 healthy unrelated comparison subjects. Patients and relatives came from families multiply affected with BD or another functional psychotic disorder. P300 amplitude and latency at midline sites were compared between the groups, using linear regression analyses and robust variance estimators for clustered data, including age and gender as covariates. Results: Bipolar disorder patients with a history of psychosis and their unaffected relatives showed significantly delayed P300 latency at Pz compared to controls. The groups did not differ in P300 amplitude. Conclusions: P300 latency delays are associated with both psychotic BD and familial liability for this illness. Sample size limited our ability to test for multimodal distribution of P300 measures among relatives, which might be expected if only a subgroup inherits any deficits. In future it will be of interest to directly compare groups of families with psychotic and non‐psychotic forms of BD to explore further the role of psychotic symptoms with regard to P300 measures in the disorder. Our results indicate that delayed P300 latency is a promising candidate endophenotype for psychotic BD, as well as schizophrenia, and may reflect the impact of shared susceptibility genes for both types of psychosis.     

躯体形式障碍患者认知功能与事件相关电位P300的研究

目的:探讨躯体形式障碍患者的认知功能状况及其与P300的关系. 方法:对120例躯体形式障碍患者及60例正常对照组分别进行P300检测和瑞文标准推理测验、数字广度与数字符号测验,并对结果进行比较. 结果:躯体形式障碍组的瑞文推理、数字广度、数字符号分数均低于对照组,差异有统计学意义(P＜0.01);N1、P2、P3潜伏期较对照组延长,N1N2、N2P2、P2P3波幅低于对照组,差异有统计学意义(P＜0.01或P＜0.05);瑞文推理分数与N1潜伏期正相关;数字广度分数与P2潜伏期、N2潜伏期正相关,与N1N2波幅负相关;数字符号分数与N1N2波幅、P2P3波幅正相关,与N2P3波幅负相关. 结论:躯体形式障碍患者的认知功能缺陷范围较广,不同的P300成分可能反映躯体形式障碍不同类型的认知功能损害.     

Specific impairment of BAER's in Friedreich's ataxia. Auditory evoked responses in clinical evaluation and differential diagnosis

We have investigated brainstem and cortical auditory responses (BAERs and CAERs) in 16 cases of Friedreich's ataxia (FA) and have compared the findings with those obtained in 2 cases of familial spastic paraplegia (FSP), in 5 cases of Charcot-Marie-Tooth disease (CMTD), and in 6 cases of atypical FA of uncertain classification. BAERs could not be elicited in 11 FA patients and constantly disappeared at a higher intensity threshold than in normal subjects in the remaining 5 patients. BAERs were normal or only slightly abnormal in FSP and CMTD patients. CAERs were normal in all 29 patients. BAERs tended to disappear with the progression of FA and BAER thresholds were correlated with the Inherited Ataxias Clinical Rating Scale score, which is an index of the severity of illness. BAERs contributed to the diagnosis, or exclusion of FA in patients with an atypical picture. It is suggested that in FA myelinated fibers in the spiral ganglion are partially affected, resulting in the decrease of wave amplitude such as occurs for peripheral sensory potentials.     

Diagnostic value of event-related evoked potentials N200 and P300 subcomponents in early diagnosis of Alzheimer's disease and mild cognitive impairment.

Event-related potentials (ERPs) have a large application in the evaluation of cognitive processes, particularly in Alzheimer's disease (AD). The aim of the present study was to evaluate the clinical relevance of event-related evoked potentials (N2 and P3 subcomponents) in early diagnosis of AD and mild cognitive impairment (MCI). We prospectively studied 60 subjects. They all underwent the following investigations: neurologic and neuropsychological examination; functional evaluation, i.e., ERPs; cerebral imagery (morphologic and functional). Subjects were classified into 3 groups: group 1: 30 dementia of Alzheimer type (NINCDS-ADRDA, DSM-IV criteria); group 2: 20 MCI; and group 3: 10 control subjects. ERPs were significantly different between the groups (AD, MCI, control subjects), with a marked increase of P3 latencies, particularly when compared with N2 latencies (P < 0.0001). Furthermore, sensitivity was 87% to 95% for the differentiation of AD patients from MCI and control subjects, using prolonged P3 latencies (specificity, 90% to 95%), whereas using N2 prolonged latencies, sensitivity was 70% to 75% (specificity, 70% to 90%). Moreover, in the MCI group, N2 latencies strongly discriminated MCI from control subjects, with 90% sensitivity and 70% specificity and correctly categorized 80% of MCI subjects against 73% for P3. The abnormalities of N2 and P3 components may be linked, in AD and MCI, to an alteration of automatic and controlled attention processing.     

Reduced visual evoked responses in multiple sclerosis patients with optic neuritis: comparison of functional magnetic resonance imaging and visual evoked potentials.

The limited application of functional magnetic resonance imaging (fMRI) for investigations of multiple sclerosis (MS) patients has already shown that deficits of the motor, cognitive and visual systems may be identified by differences in the patterns of activation in response to a suitable stimulus. In MS patients with unilateral optic neuritis, the area of activation in the primary visual cortex, measured by fMRI techniques, is dramatically reduced in response to stimulation of the affected eye. The latency of the major positive component of the visual evoked potential (VEP) recorded upon stimulation of the affected eye is significantly increased in these patients, as compared to the unaffected eye and normal volunteers. We have found a correlation between the neural response measured using fMRI and the latency of the VEP. fMRI signal responses have the potential to provide more detailed topographic information relating to functional deficits in MS.     

Auditory brain-stem responses in comatose patients: relationship with brain-stem reflexes and levels of coma.

Auditory brain-stem responses (BSR) were recorded in 20 comatose patients in whom the level of brain-stem dysfunction was defined by clinical assessment of brain-stem reflexes and posture. No BSR abnormalities were found in the 10 cases with cortico-subcortical or diencephalic levels. The other 10 patients showed a clear relationship between alteration of the different components of the BSR and the clinical levels of brain-stem dysfunction caused by the rostro-caudal evolution. Alteration of wave P5 seems related to a midbrain dysfunction, of P3 to a pontine dysfunction and of P1 or P2 to a lower brain-stem dysfunction.     

酒依赖相关精神障碍患者的脑干听觉反应及P300异常变化

目的探讨酒依赖患者脑干听觉反应(ABR)及P300的特点.方法以click短声、听觉靶刺激和非靶刺激为诱发事件,检测26例男性酒依赖患者及31名男性正常人的ABR和事件相关电位P300.结果 (1)ABR与对照组比较,酒依赖组波Ⅱ～波Ⅶ的绝对潜伏期长,波Ⅱ～波Ⅴ的绝对波幅低,差异均有显著性和非常显著性(P<0.05或P<0.01);(2)P300在靶刺激中,酒依赖组的P2和P3潜伏期[分别为(187±26)ms和(319±27)ms]长于对照组[分别为(171±21)ms和(302±16)ms],P2和P3波幅[分别为(3.9±2.3)μV和(3.5±3.1)μV]低于对照组[分别为(6.0±2.1)μV和(8.2±4.1)μV];在非靶刺激中,酒依赖组的N1潜伏期[(108±14)ms]长于对照组[(98±12)ms];差异有显著性和非常显著性(P<0.05或P<0.01).结论长期大量饮酒不仅损害脑干功能,同时损害皮层认知功能.     

P300 latency reflects the degree of cognitive decline in dementing illness

An auditory discrimination paradigm was employed to elicit the P3 component of the event-related brain potential (ERP) from 39 demented patients (mean age = 71 years). Component latency was longer in patients who were diagnosed as having primary degenerative dementia and other cognitive impairment disorders compared to age-matched controls. Neurologist ratings of cognitive impairment were significantly correlated with P3 latency values, although no differences in mean latency were obtained between the various categories of dementia. ERP measurement techniques and the interpretation of P3 latency as in index of dementing illness are discussed.