Correlation of cognitive function with acetylcholinesterase activity and P300 event-related potential of patients with type 2 diabetes mellitus

BACKGROUND： At present, central cholinergic neuron system is regarded the most major structural basis of cognitive function. Changes in structure of cholinergic neuron system of brain and receptor expression after brain injury can cause cognitive impairment. OBJECTIVE＂ To comparatively observe the intelligence quotient （IQ）, latent period and wave amplitude of P300 event-related potential and the difference of activity of acetylcholinesterase （ACHE） in blood and cerebrospinal fluid between patients with type 2 diabetes mellitus and with non-diabetes mellitus, and analyze the correlation of IQ of cognitive impairment patients with diabetes mellitus with AChE activity, latent period and wave amplitude of P300 event-related potential in cerebrospinal fluid. DESIGN： Correlation analysis of contrast observation SETTING： Department of Endocrinology, Affiliated Hospital of Binzhou Medical College PARTICIPANTS： Totally 32 patients with type 2 diabetes mellitus who received the treatment in the Department of Endocrinology, Affiliated Hospital of Binzhou Medical College between April 2004 and April 2005 were recruited, serving as diabetes mellitus group. They, including 19 male and 13 female, aged 49 to 73 years, with disease course of 4 to 11 years, all met the diagnostic criteria of diabetes mellitus revised by World Health Organization in 1999. Another 30 patients with non-diabetes mellitus who homeochronously underwent lumbar anesthesia in the Department of Surgery and Department of Gynecology were recruited, serving as non-diabetes mellitus group. The 30 patients included 18 male and 12 female, and their age ranged from 46 to 71 years. Informed consents of detected items were obtained from the involved patients. METHODS： ① Evaluation,on IQ： The IQ of involved subjects was evaluated with Chinese Version of the Wechsler Adult Intelligence Scale revised by Gong Yao-xian （WAIS-RC）. WAIS-RC included 6 verbal subscales and 5 performance subscales. The test scores of the 11 subscales integrated into the scores of the whole scale, and the scores on the WAIS-RC included verbal IQ （VlQ）, performance IQ （PIQ） and full scale IQ （FIQ）. FIQ ≤79 scores indicated low IQ and FIQ≤69 indicated intelligence impairment. ② Detection of P300 wave： P300 wave was detected with evoked potential instrument （MYTOPRO, Italian）, and data of latent period and amplitude of P300 event-related potential were automatically shown by computer. ③ Detection of AChE activity in blood and cerebrospinal fluid： Activity of AChE of blood and cerebrospinal fluid was measured with biochemical methods by using CORNING-560 autoanalyzer.④Correlation analysis： Correlation of FIQ with AChE of cerebrospinal fluid and P300 wave of patients with type 2 diabetes mellitus was analyzed, t test was used in intergroup comparison and linear correlation analysis for relevant treatment. MAIN OUTCOME MEASURES： ① Comparison of IQ, latent period and wave amplitude of P300 wave as well as the activity of AChE between two groups. ② Analysis on the correlation of FIQ of patients with type 2 diabetes mellitus with AChE of cerebrospinal fluid and P300 wave. RESULTS： Thirty-two patients with diabetes mellitus and 30 non-diabetes mellitus participated in the result analysis. ①Comparison of IQ, latent period and wave amplitude of P300 wave as well as the activity of AChE between two groups： The scores of VIP, PIQ and FIQ of patients with type 2 diabetes mellitus were （97.4±10.4）. （92.6±8.4） and （95.2±9.7） scores, respectively; and those of patients with non-diabetes mellitus were （104.7±9.6）, （102.5±8.5）and（102.7±8.9） scores, respectively, and P 〈 0.05-0.01 was set in intergroup comparison. The latent period of P300 wave at points Fz , Cz and Pz of patients with type 2 diabetes mellitus was （370.8±41.8）.（371.5±39.1）and （375.1±43.1） ms, respectively, and that of patients with non-diabetes mellitus was （ 332.1 ±28.3 ）, （335.7 ±29.4）and （339.7 ±27.3） ms, respectively, and P 〈 0.01 was set in intergroup comparison; Wave amplitude of P300 of patients with type 2 diabetes mellitus was （8.6±4.1）,（8.6±4.0） and （7.7±4.0） μV, respectively and that of patients with non-diabetes mellitus was （11.9±4.1）,（11.5±4.4） and （10.9±5.0） μV, respectively , and P 〈 0.05-0.01 was set in intergroup comparison; The level of AChE in blood and cerebrospinal fluid of patients with type 2 diabetes mellitus was （235.61 ±50.34）and （17.89±4.46） μkat/L, respectively, which was significantly higher than that of patients with non-diabetes mellitus [（205.03±44.15）and （14.63±0.48） μkat /L, respectively], and P 〈 0.05-0.01 was set in the intergroup comparison. ② Correlation of FIQ value of patients with type 2 diabetes mellitus with AChE of cerebrospinal fluid and P300 wave： The value of FIQ was significantly negatively correlated with the AChE activity of cerebrospinal fluid （r=-0.588 1, P 〈 0.01 ）, significantly negatively correlated with the latent period at points Fz. C and Pz of P300 wave （r= -0.700 5, -0.689 4, -0.688 5, P 〈 0.01 ）, and significantly positively correlated with the amplitude at points Fz . Cz and Pz of P300 wave（r= 0.607 4,0.616 1,0.592 0,P 〈 0.01 ）. CONCLUSION： ① Cognitive impairment of patients with type 2 diabetes mellitus might be related to the increase of activity of AChE in cerebrospinal fluid. ②Combined application of examination of P300 wave and evaluation of IQ is more useful in deciding the state of cognitive function of patients with type 2 diabetes mellitus.

Mismatch negativity,social cognition,and functional outcomes in patients after traumatic brain injury

Mismatch negativity is generated automatically, and is an early monitoring indicator of neuronal integrity impairment and functional abnormality in patients with brain injury, leading to decline of cognitive function. Antipsychotic medication cannot affect mismatch negativity. The present study aimed to explore the relationships of mismatch negativity with neurocognition, daily life and social functional outcomes in patients after brain injury. Twelve patients with traumatic brain injury and 12 healthy controls were recruited in this study. We examined neurocogni-tion with the Wechsler Adult Intelligence Scale-Revised China, and daily and social functional outcomes with the Activity of Daily Living Scale and Social Disability Screening Schedule, re-spectively. Mismatch negativity was analyzed from electroencephalogram recording. The results showed that mismatch negativity amplitudes decreased in patients with traumatic brain injury compared with healthy controls. Mismatch negativity amplitude was negatively correlated with measurements of neurocognition and positively correlated with functional outcomes in patients after traumatic brain injury. Further, the most signiifcant positive correlations were found be-tween mismatch negativity in the fronto-central region and measures of functional outcomes. The most signiifcant positive correlations were also found between mismatch negativity at the FCz electrode and daily living function. Mismatch negativity amplitudes were extremely positive-ly associated with Social Disability Screening Schedule scores at the Fz electrode in brain injury patients. These experimental ifndings suggest that mismatch negativity might efifciently relfect functional outcomes in patients after traumatic brain injury.

Effects of Electroacupuncture Combined Psycho-intervention on Cognitive Function and Event-Related Potentials P300 and Mismatch Negativity in Patients with Internet Addiction

Objective： To observe the effects of comprehensive therapy （CT） with electroacupuncture （EA） in combination with psycho-intervention （PI） on the cognitive function and event-related potentials （ERP）, P300 and mismatch negativity （MMN）, in patients with internet addiction （IA） for a preliminary exploration of the possible mechanism of the therapy. Metheds： One hundred and twenty patients with IA were randomly divided into three groups, and a total of 112 subjects reached the final analysis of the trial, the EA group （39 patients）, the PI group （36 patients） and the CT group （37 patients）. EA was applied at acupoints Baihui （GV20）, Sishencong （EX-HN1）, Hegu （LI4）, Neiguan （PC6）, Taichong （LR3） and Sanyinjiao （SP6）, once every other day; PI with the cognition- behavior mode was implemented every 4 days; both EA and PI were used in the CT group. The treatment course for all patients was 40 days. Changes before and after treatment in terms of scoring by the IA self-rating scale, short-term memory capacity, short-term memory span, and the latency and amplitude of P300 and MMN in patients were observed. Results： After treatment, in all groups, the IA score was lowered significantly （P〈0.05） and scores of short-term memory capacity and short-term memory span increased significantly （P〈0.05）, while the decreased IA score in the CT group was more significant than that in the other two groups （P〈0.05）. ERP measurements showed that P300 latency was depressed and its amplitude raised in the EA group; MMN amplitude increased in the CT group （all P〈0.05）. Cenclusien： The EA in combination with PI could improve the cognitive function of IA patients, and its mechanism might be related to the speedup of cerebral discrimination on external stimulus and the enhancement of effective resource mobilization during information processing of the brain.

Effect of escitalopram on cognitive function in depressionA mismatch negativity potentials study

We detected the event-related potential mismatch negativity （MMN） of 30 depression patients and compared to 30 age,gender,and education-matched healthy controls.Results showed that amplitudes of frequency and duration MMN were lower in depression patients compared with control patients,indicating abnormality in auditory processing （i.e.,cognitive impairment）.Following escitalopram treatment for 8 weeks,the amplitudes of frequency and duration MMN were significantly increased and Hamilton Rating Scale for Depression scores were significantly decreased in depression patients.These data suggest that escitalopram can improve cognitive function of patients with depression.Further,MMN may be a useful tool for evaluating cognitive function and treatment effects.

Assessment of cognitive dysfunction in traumatic brain injury patients:a review

Traumatic brain injury(TBI)is one of the major causes of human mortality and morbidity in the world.Brain injury could affect the core of a person’s being–their thinking,memory,personality and behaviour.Electrophysiological markers from the human electroencephalogram and brain imaging provide a rich source of data which helps to elucidate specific processing impairments in TBI patients.To assess the cognitive and social function in traumatic brain injury patients,this review will focus on some of methods for assessing the disabling cognitive and social function deficits induced by TBI.There are many new technologies available to address TBI and recognition related questions.Integration of the various techniques will help to facilitate our comprehending of TBI,cognitive function and social function,and improve treatment and rehabilitation.

低频重复经颅磁刺激对颅脑外伤后认知功能及P300电位的影响

目的研究低频重复经颅磁刺激(rTMS)对颅脑外伤(TBI)患者认知功能及P300电位的影响。方法纳入2019年12月至2021年6月江苏省南通市第一人民医院神经外科和康复医学科住院的50例TBI患者,根据随机数字表法将其分为试验组及对照组,各25例。两组均接受临床基础治疗及常规的认知功能训练,试验组在此基础上增加低频rTMS治疗,对照组辅以假刺激治疗,连续治疗6周。比较治疗前后简易智能精神状态评价检查量表(MMSE)、洛文斯顿认知评定量表(LOTCA)、P300波幅和潜伏期;观察治疗期间不良反应的发生情况。结果治疗后,两组定向力、记忆力、回忆能力、注意力和计算力、语言能力及MMSE总分高于治疗前,且试验组定向力、注意力与计算力及MMSE总分高于对照组,差异有统计学意义(P<0.05)。治疗后,两组定向、视知觉、空间知觉、动作运用、视运动组织、思维操作、注意力及专注力及LOTCA总分高于治疗前,且试验组高于对照组,差异有统计学意义(P<0.05)。治疗后,两组P300波幅大于治疗前、潜伏期短于治疗前;且试验组P300波幅大于对照组、潜伏期短于对照组,差异有统计学意义(P<0.05)。两组治疗过程中均未出现癫痫等不良反应。结论低频rTMS能够改善TBI患者的认知功能,值得临床应用推广,P300可客观体现rTMS对认知的改善效果。

P300对颅脑外伤所致精神障碍的认知功能评价

目的探讨颅脑外伤所致精神障碍认知功能障碍的特点及P300对其评价的临床价值。方法对56例颅脑外伤所致精神障碍患者和52例颅脑外伤不伴精神障碍患者以及53例健康者分别进行了P300电位测定和智商测定,并将3组结果加以比较。结果颅脑外伤所致精神障碍患者组与无精神障碍组P300电位成分中N2、P3波潜伏期延长和P3波幅降低,言语智商、操作智商、总智商得分均降低,较健康对照组差异有显著性意义(P<0.01),而颅脑外伤所致精神障碍患者组与无精神障碍组相比,P300电位成分中N2、P3波潜伏期延长和P3波幅降低,言语智商、操作智商、总智商得分均降低,差异有显著性意义(P<0.01),相关分析显示P300潜伏期与言语智商、操作智商、总智商得分呈显著负相关(r=-0.29～-0.33,P<0.01),波幅则呈显著正相关(r=0.31～0.36,P<0.01)。结论P300电位可作为评价颅脑外伤所致精神障碍患者认知状况的重要指标应用于临床。

头针治疗脑外伤后认知障碍的临床效果

目的观察头针治疗脑外伤后认知障碍的临床疗效。方法 42例脑外伤后认知障碍患者随机分为治疗组(n=23)和对照组(n=19)。对照组予认知功能训练及盐酸多奈哌齐治疗,治疗组在此基础上予头针治疗,共3个月。分别于治疗前、治疗1个月后、治疗3个月后应用蒙特利尔认知功能评定(Mo CA)及事件相关电位P300进行评估。结果治疗3个月后,两组患者P300和MoCA评分均较治疗前显著改善(P<0.001),治疗组均显著优于对照组(P<0.001)。结论头针对改善脑外伤后认知障碍有一定疗效。

伪装与非伪装认知功能损伤事件相关电位P_(300)比较研究

目的探讨检测认知功能损伤的神经电生理技术。方法以年龄、性别、文化程度及脑损伤程度基本匹配的伪装与非伪装认知功能损伤各10例脑外伤患者为研究对象,并以上述条件相匹配的10例正常人作对照。通过高低音听觉刺激高低概率范式(oddball)引发P_(300),并同步记录被试判断高低音和简单图片的正确率。结果①伪装组、非伪装组及正常对照组三组听觉高低音和简单图片判断的正确率的差异均有显著性,伪装组显著低于非伪装组和正常对照组(P<0.01);伪装组高低音判断的正确率仅为34.7%,图片判断的正确率为45.8%;而非伪装组和对照组的正确率均在90%以上。②三组在额点(Fz)、中央点(Cz)、顶点(Pz)三个导联上的P_(300)潜伏期及低、高概率事件的P300幅值差值的差异均无显著性(P>0.05)。结论事件相关电位P_(300)潜伏期及幅值差值对伪装认知功能损伤的诊断能够提供间接的神经电生理学佐证依据。

轻型颅脑外伤患者事件相关电位的研究

目的：研究事件相关电位（ＥＲＰ） 对轻型颅脑外伤患者脑认知功能变化的评估作用。方法：用听觉ｏｄｄｂａｌｌ 刺激序列ＥＲＰ检测２２ 例轻型颅脑外伤患者并和２０ 位正常人对照。结果：病例组ＥＲＰ 的Ｐ３ 峰潜伏期较正常对照组明显延长（Ｐ＜０－０１） ；随着病情的好转，Ｐ３ 潜伏期逐渐缩短，波幅亦逐渐增高。结论：ＥＲＰ是测定轻型颅脑外伤患者脑认知功能变化的一项客观指标。

颅外伤所致精神障碍患者的P_(300)电位研究

目的探讨颅外伤所致精神障碍P300电位特征及其在评价其认知功能中的临床价值。方法对56例颅外伤所致精神障碍患者和53例健康者分别进行了P300电位测定和智商测定,并将两组结果加以比较。结果颅外伤所致精神障碍患者组P300电位成分中N2、P3波潜伏期延长和P3波幅降低,较对照组差异有显著性(P<0.01),韦氏智力量表中领悟、算术和数字广度等分量表值颅外伤所致精神障碍组均低于对照组,差异有显著性(P<0.05或P<0.01)。相关分析显示P300潜伏期与领悟、算术和数字广度值呈显著负相关(r=-0.29～-0.33,P<0.01),波幅则呈显著正相关(r=0.31～0.36,P<0.01)。结论P300电位可作为评价颅外伤所致精神障碍患者认知状况的重要指标应用于临床。

闭合性颅脑外伤患者事件相关电位的研究

目的：研究ERP对闭合性颅脑外伤患者脑认知功能变化的评估作用。方法：应用Medicid-03E脑诱发电位仪测定168例闭合性颅脑外伤患者的视觉（图像）、听觉诱发的P3波之潜伏期和波幅，并与正常对照组作比较，54例患者进行复测比较。结果：病人组P3潜伏期较正常对照组明显延长（P＜0．001），波幅降低；P3波潜伏期、波幅与患者病情严重程度相关；有原发昏迷者改变尤为突出；随着病情的好转，P3潜伏期逐渐缩短，波幅亦逐渐增高。结论：ERP是测定闭合性颅脑外伤患者脑认知功能变化的一项客观指标。

轻型颅外伤患者的认知功能研究

目的:探讨轻型颅外伤患者的认知状况及P300电位在评价其认知功能中的临床价值。方法:对52例轻型颅外伤患者和50例 健康者分别进行了P300电位测定和认知能力筛查实验,并将两组结果加以比较。结果:轻型颅外伤患者组P300电位成分中N2、P3波潜伏期延 长和P3波幅降低,较对照组差异有显著性意义(P<0.05),筛查量表中9个因子分及总分值轻型颅外伤组均低于对照组,差异有显著性意义 (P<0.05或P<0.01)。结论P300电位可作为评价轻型颅外伤患者的认知状况的重要指标应用于临床。

闭合性颅脑外伤患者病程与P_(300)之间关系的研究

目的:研究闭合性颅脑外伤患者病程与P_(300)之间的关系,探讨此类患者作P_(300)测定的最佳时间。方法:应用Medicid-03E脑诱发电位仪测定518例闭合性颅脑外伤患者的视觉(图像)刺激诱发的P_(300)波之潜伏期和波幅。对其中异常的385例与214例正常对照组作比较,并比较不同伤情、伤后不同时间患者的P_(300)波。结果:病人组P_(300)波潜伏期较正常对照组明显延长(P<0.001),波幅亦明显降低(P<0.01),其P_(300)改变在伤后25至48小时内明显,尤以伤后有昏迷者更为突出。随着时间的延长,P_(300)波异常程度有所改善。结论:P_(300)波的变化可作为判断闭合性颅脑外伤患者脑认知功能变化的一项客观指标,其中伤后25至48小时内测定具有更高的价值,根据P_(300)波的变化能判断患者的伤情和预后。

丙泊酚联合芬太尼麻醉应用于重型颅脑损伤急诊手术患者对其脑血流动力学及认知功能的影响分析

目的分析丙泊酚联合芬太尼麻醉对重型颅脑损伤急诊手术患者的脑血流动力学及认知功能的影响。方法回顾性分析2014年1月至2017年2月收治的伤后24 h内的急性重型颅脑损伤72例患者,随机分为观察组和对照组各36例。对照组均气管插管后吸入异氟醚维持麻醉,观察组均给予芬太尼与丙泊酚联合麻醉处理。比较两组患者诱导前(T0)、诱导后1 min(T1)、插管后5 min(T2)、插管后10 min(T3)时间点的脑血流动力学参数、心率(HR)及平均动脉压(MAP),此外采用简易智能精神状态量表(MMSE)评定两组患者手术前后的神经精神功能,并通过MMSE评分认定两组患者认知功能缺损(POCD)情况。结果两组患者T1~T3期较同组T0期Qmean和Vmean均出现不同程度的变化,对照组显著降低(P<0.05),而观察组变化差异无统计学意义(P>0.05);两组PI指数和RI指数均较T0期显著升高(P<0.05),观察组T1期各参数较对照组变化幅度更小(P<0.05),T2~T3期差异无统计学意义(P>0.05);T1期两组患者的HR和MAP均较T0期显著降低(P<0.05),T2期、T3期较T0期比较差异无统计学意义(P>0.05),组间同期比较差异亦无统计学意义(P>0.05)。相较于术前,术后1 d两组的MMSE评定均明显减低(P<0.05),相较于对照组,术后1 d观察组患者的MMSE评分下降较少(P<0.05),两组患者术后1周及1个月的MMSE评分与术前比较,差异无统计学意义(P>0.05)。术后1 d,观察组POCD的发生率明显低于对照组(P<0.05),此外术后1周对照组尚有3例POCD患者,此时观察组已无POCD患者。结论对重型颅脑损伤患者采用丙泊酚与芬太尼联合麻醉,有利于患者脑血流动力学的稳定,对患者的认知功能影响更小,可有效降低术后患者认知功能障碍的发生,值得推广应用。

颅脑损伤后所致癫痫患者的事件相关电位P_(300)特征

目的探讨颅脑外伤所致癫痫患者的认知功能特点及事件相关电位P300的临床应用价值。方法对53例颅脑外伤所致精神障碍患者、52例颅脑外伤不伴癫痫患者和50例健康对照组分别进行了P300电位测定,采用韦氏成人智力测验修订版测定智商,将三组测定结果进行相关分析。结果颅脑外伤所致癫痫患者组与颅脑外伤组事件相关电位成分中N2、P3波潜伏期延长和P3波幅降低,言语智商、操作智商、总智商得分均降低均较对照组显著,差异均有极显著性(P均<0.01);而颅脑外伤伴癫痫组P300电位成分中N2、P3波潜伏期延长和P3波幅降低及言语智商、操作智商、总智商得分降低均较颅脑外伤组显著,差异均有极显著性(P均<0.01)。相关分析显示,颅脑外伤伴癫痫组P300潜伏期与言语智商、操作智商和总智商分呈显著负相关(r=-0.33～-0.29,P<001),波幅则呈显著正相关(r=0.31～0.36,P<0.01)。结论P300电位是评价颅脑外伤所致癫痫患者认知状况的重要指标。

Connecting the P300 to the diagnosis and prognosis of unconscious patients

The residual consciousness of unconscious patients can be detected by studying the P300, a wave among event-related potentials. Previous studies have applied tones, the subject＇s name and other names as stimuli. However, the results were not satisfactory. In this study, we changed the constituent order of subjects＇ two-character names to create derived names. The subject＇s derived names, together with tones and their own names, were used as auditory stimuli in event-related potential experiments. Healthy controls and unconscious patients were included in this study and made to listen to these auditory stimuli. In the two paradigms, a sine tone followed by the subject＇s own name and the subject＇s derived name followed by the subject＇s own name were used as standard and deviant stimuli, respectively. The results showed that all healthy controls had the P300 using both paradigms, and that the P300 in the second paradigm had a longer latency and two peaks. All minimally conscious state patients had the P300 in the first paradigm and the majority of them had the P300 in the second paradigm. Most vegetative state patients had no P300. Patients who showed the P300 in the two paradigms had more residual consciousness, and patients with the two-peak P300 had a higher probability of awakening within a short time. Our experimental findings suggest that the P300 event-related potential could reflect the conscious state of unconscious patients.

创伤性脑损伤大鼠P300检测与海马microRNA表达变化

目的探讨创伤性脑损伤后大鼠海马microRNA的表达变化与认知功能障碍的相关性。方法 25只SD大鼠随机分为假手术组和伤后1h、1d、3d、5d组,采用Feeney自由落体法建立创伤性脑损伤动物模型。各组大鼠于设定的损伤时间点检测事件相关电位P300,应用基因芯片技术检测海马microRNA的表达情况,筛选特异性表达的microRNA。结果各组大鼠伤后P300的潜伏期延长,波幅下降,以伤后1d为甚。与假手术组相比,伤后各实验组microRNA表达谱具有显著差异。其中miR-21、miR-16、let-7b的表达与P300潜伏期变化存在显著相关,伤后1d为差异性表达的关键时间点。结论 microRNA可能在创伤性脑损伤后发生的认知功能障碍中发挥调控作用,有望为脑损伤后认知功能的法医学鉴定提供新的思路。

轻型颅脑外伤患者事件相关电位的研究

目的 研究事件相关电位 (ERP)对轻型颅脑外伤患者脑认知功能变化的评估作用。方法用听觉oddball刺激序列ERP检测 2 2例轻型颅脑外伤患者并和 2 0位正常人对照。结果 病例组ERP的P3 峰潜伏期较正常对照组明显延长 (P <0 .0 1) ;随着病情的好转 ,P3 潜伏期逐渐缩短 ,波幅亦逐渐增高。结论 ERP是测定轻型颅脑外伤患者脑认知功能变化的一项客观指标。

Effects of Risperidone and Paliperidone on Brain-Derived Neurotrophic Factor and N400 in First-Episode Schizophrenia

Background：Risperidone and paliperidone have been the mainstay treatment for schizophrenia and their potential role in neuroprotection could be associated with brain-derived neurotrophic factor （BDNF） and N400 （an event-related brain potential component）.So far,different effects on both BDNF and N400 were reported in relation to various antipsychotic treatments.However,few studies have been conducted on the mechanism ofrisperidone and paliperidone on BDNF and N400.This study aimed to compare the effects ofrisperidone and paliperidone on BDNF and the N400 component of the event-related brain potential in patients with first-episode schizophrenia.Methods：Ninety-eight patients with first-episode schizophrenia were randomly divided into the risperidone and paliperidone groups and treated with risperidone and paliperidone,respectively,for 12 weeks.Serum BDNF level,the latency,and amplitude of the N400 event-related potential before and after the treatment and Positive and Negative Syndrome Scale （PANSS） scores were compared between the two groups.Results：A total of 94 patients were included in the final analysis （47 patients in each group）.After the treatment,the serum BDNF levels in both groups increased （all P 〈 0.01）,while no significant difference in serum BDNF level was found between the groups before and after the treatment （all P 〉 0.05）.After the treatment,N400 amplitudes were increased （from 4.73 ± 2.86 μv and 4.51 ± 4.63 μv to 5.35 ± 4.18 μv and 5.52 ± 3.08 μv,respectively） under congruent condition in both risperidone and paliperidone groups （all P 〈 0.01）.Under incongruent conditions,the N400 latencies were shortened in the paliperidone group （from 424.13 ± 110.42 ms to 4.7.41 ± 154.59 ms,P 〈 0.05）,and the N400 amplitudes were increased in the risperidone group （from 5.80 ± 3.50 μv to 7.17 ± 5.51 μv,P 〈 0.01）.After treatment,the total PANSS score in both groups decreased significantly （all P 〈 0.01）,but the difference between the groups was not significant （P 〉 0.05）.A negative correlation between the reduction rate of the PANSS score and the increase in serum BDNF level after the treatment was found in the paliperidone group but not in the risperidone group.Conclusions：Both risperidone and paliperidone could increase the serum BDNF levels in patients with first-episode schizophrenia and improve their cognitive function （N400 latency and amplitude）,but their antipsychotic mechanisms might differ.