弱视儿童图形视觉诱发电位分析

弱视是妨碍儿童视觉发育的严重眼病之一。近年来 ,视觉诱发电位 (ＶＥＰ)已成为研究弱视发病机理 ,进行临床诊断和评价预后的一项重要手段。笔者于 1996年 9月至 1998年9月对 34例弱视儿童进行图形视觉诱发电位 (Ｐ ＶＥＰ)检测分析 ,现报告如下。1　 对象和方法研究对象 :34例弱视儿童中 ,单眼弱视 18例 ,男 10例 ,女 8例 ,共 18眼 ,年龄 3～ 14岁 ,弱视眼视力 0 0 7～ 0 6 ;双眼弱视 16例 ,男 7例 ,女 9例 ,共 32眼 ,年龄 4～ 14岁 ,视力 0 1～ 0 7。弱视依文献 [1]分度 ,两组患者中 ,轻度弱视 10眼 ,中度 16眼 ,重度 2 4眼。以同年龄…     

弱视儿童的视觉诱发电位用不同记录方法的比较研究

用66只健康眼得出VEP正常的三项标准,分析52只弱视眼O_1、O_2、O_z三个记录点的VEP,其异常率:O_z一点记录为23.07％,O_1、O_2点记录为75％,O_1、O_2、O_z三点记录为80.77％。分析结果表明,弱视眼O_1、O_2点的VEP潜伏期较O_z点显著延长,波幅显著低于O_z点。     

不同类型弱视的图形视觉诱发电位波形分析

目的分析屈光参差性弱视眼、屈光不正性弱视眼、斜视性弱视眼、高度近视伴弱视眼的图形视觉诱发电位(PVEP)波形特性。方法回顾性分析40例不同类型弱视眼的PVEP检查结果,观察P100波幅值及潜伏期的特点。结果几种弱视眼的P100波幅值降低无明显规律,且屈光参差性弱视眼中P100波幅值降低程度与视力的降低程度无明显关系。潜伏期有一定程度延迟,按照由短到长的顺序排列为屈光不正性弱视、屈光参差性弱视、斜视性弱视、高度近视伴弱视。结论弱视眼神经传导速度均有一定程度的变慢,按传导速度由快到慢的顺序排列为屈光不正性弱视、屈光参差性弱视、斜视性弱视、高度近视伴弱视。因单纯屈光不正性、屈光参差性弱视眼的潜伏期延迟较少,而球后视神经炎的P100波潜伏期延迟明显,可以作为鉴别诊断的参考。     

图形翻转视觉诱发电位诊治儿童屈光不正性弱视

目的对比近视性、远视性、散光性弱视患儿治疗前后的图形翻转视觉诱发电位（eR．VEP）,探讨不同性质屈光不正性弱视的治疗效果。方法筛选2009年5月至2011年5月本院诊治的年龄6～7岁的弱视患儿90例,分为近视性、远视性及混合散光性3组,每组各30例60只眼,30例健康儿童60只眼作为对照,采用视觉诱发电位仪作PR—VEP检测,记录并比较弱视治疗前后各组P100潜伏期和P波振幅的变化。结果治疗前,与健康儿童组比较,3组弱视眼组PR．VEP的P100潜伏期延长,P波振幅下降。与远视性弱视组和散光性弱视组相比,近视性弱视组P100潜伏期最长（均P〈0．05）,P波振幅最低（均P〈0．05）,而远视性弱视组和散光性弱视组之间差异无统计学意义。与治疗前比较,3组弱视患儿弱视眼在治疗之后P100的潜伏期缩短,P波振幅上升。近视性、远视性及混合散光性3组弱视患儿治疗前后的潜伏期差值和振幅差值之间差异也有统计学意义[潜伏期差值：（2．640±0．009）ms比（5．590±0．576）ms比（6．989±2．229）ms,振幅差值：（0．929±0．611）μV比（2．595±0．464）μV比（2．575,0．211）μV,均P〈0．05],近视性弱视的潜伏期差值和振幅差值最小。结论近视性弱视治疗前后的潜伏期差信和振幅差佰最小．证实了沂视件弱视的难治件．PR．VEP榆涮对弱视的临床治疗具右指导膏叟．     

8.5—10岁正常儿童视觉诱发电位测定

目的 :了解 8.5～ 10岁正常儿童视觉诱发电位基值 ;方法 :以 DISA2 0 0 0 C型肌电仪对 8.5 - 10岁的 5 0名正常儿童 (男 2 5名 ,女 2 5名 )进行了视觉诱发电位 ( Visual Evoked Potential,VEP)测试 ;结果 :被试儿童 VEP波的形态极为规整和相似 ,可分别描述为 :( 1)陡峭型 ,P3出现 ,4 0例 ;( 2 )陡峭型 ,P3不出现 ,4例 ;( 3 ) W型 ,P3出现 ,6例。 VEP各波的出现率分布在 4 2 % - 10 0 % ,其中 ,主波群 ( N1- P2 - N2 )的出现率为 82 % ,10 0 % ,10 0 % ,P3波的出现率为 92 % ,提示 8.5 - 10岁儿童脑的发育程度已相当高 ,顶叶联合皮层已基本成熟和完善。对随机抽取的5例被试在第一次测试后的 14天和 4 4天进行的相同条件的重复测试显示儿童 VEP测试的稳定性好 ,左右眼测试比较差异无显著性 ,可作为神经系统疾病和脑发育、脑功能的检查手段。主波群性别间比较显示 ,右眼刺激记录的 N1波潜伏期、左右眼刺激记录的 N2波潜伏期差异有显著性 ,其原因可能是 N1、 N2波所代表的视觉传导路、皮层和丘脑激活系统的功能存在差异 ,也可能是由于不同性别儿童生长发育速度不同导致。结论 :8.5 - 10岁儿童 VEP十分稳定 ,可做为脑发育及脑功能的检查手段。     

注意障碍、多动综合征儿童视觉诱发电位初步观察

本研究记录了36例ADHD患儿在两种不同注意状态(主动注意、被动注意)视觉诱发电位(VEP)晚成分的变化。结果:正常组主动注意状态P_3波出现率较被动注意状态高,主动——被动注意状态间VEP的N_1—P_2波幅变异大。而ADHD组患儿主动—被动注意状态间P_3波出现率无差异,N_1—P_2波幅变异小,但轻、中、重症之间N_1—P_2波幅变异有区别且逐渐减小。结果提示:ADHD患儿的主动注意力较正常儿差,VEP晚成分的检查可以为ADHD的诊断提供一定的客观依据。     

正常儿童与低智儿童的听觉、视觉诱发电位的初步研究

本文对正常儿童与低智儿童作了视觉诱发电位(VEP)和听觉诱发电位(AEP)的研究。发现低智组与正常儿童组相比潜伏期延长、波幅降低,后成份活跃。作者认为最有价值的是低智儿童组长潜伏期后成份P_4的90.01％出现率可区别于其它精神科疾病的长潜伏期诱发电位的表现。     

酒精依赖者视觉诱发电位的研究

目的：本研究旨在通过对酒精依赖者模式翻转视觉诱发电位（ＰＲＶＥＰ）的研究，为了解酒精依赖者的生理和心理功能损害提供客观指标。方法：酒精依赖者６２人，正常对照者４０人，采用日本产Ｎｅｕｒｏｐａｃｋ－２型诱发电位仪，分别对其进行模式翻转视觉诱发电位（ＰＲＶＥＰ）记录。结果：与正常对照组相比，酒精依赖者ＰＲＶＥＰ波潜伏期延长，波幅降低，主波群异常，晚成份出现率低，周期不明显及侧性优势现象消失，差异具有显     

不同颜色单色光产生的稳态视觉诱发电位的比较

人的视网膜上的视锥细胞是明视条件下视觉形成的感应器，可分为红锥细胞、绿锥细胞、蓝锥细胞。每类锥细胞有不同的光谱吸收特性。用10Hz的脉冲分别驱动红、绿、蓝三种发光二极管，使其产生同样强度的单色光，用这些单色光分别对10个受试者的双眼进行刺激，用128道的脑电系统对受试者的脑电进行记录。通过对所有电极处的稳态视觉诱发电位（Steady—state visually evoked potential，SSVEP）进行频谱分析，发现不同类视锥细胞输出的信号在视觉初级皮质激发的神经网络分布基本一致，但在各自网络引起的反应强度有差别：蓝光最强，红光次之，绿光最弱。     

肝豆状核变性患者VEP、SEP及BAEP的对比研究

目的 :观察肝豆状核变性 (Wilson)病患者及直系亲属视觉诱发电位 (VEP)、体感诱发电位 (SEP)及脑干听觉诱发电位 (BAEP)的变化。方法 :对 10例Wilson病患者及其 18名直系亲属进行VEP、SEP及BAEP检测并分析其结果。结果 :5例患者双侧和 2例患者单侧VEP的P10 0潜伏期 (PL)延长。 1例患者双侧和 3例患者单侧SEP的N13-N2 0的波间潜伏期 (IPL)延长。 1例患者双侧和 2例患者单侧BAEP的Ⅲ -Ⅴ的IPL和Ⅰ -Ⅴ的IPL延长。提示Wilson病患者视觉、躯体感觉及听觉神经传导通路有不同程度的电生理活动障碍。 18名直系亲属中有 4名双侧和 3名单侧VEP的P10 0PL有不同程度的延长 ,2名亲属单侧BAEP的Ⅲ -Ⅴ和Ⅰ -Ⅴ的IPL延长。结论 :Wilson病患者的VEP、SEP及BAEP有明显的变化 ,提示Wilson病患者早期即有感觉通路功能异常     

Brain mapping of bilateral visual interactions in children

Interhemispheric interactions were studied with functional brain mapping of visual processing. Children performed a reaction time task with uni- and bilateral targets and nontargets. The visual evoked potential (VEP) was segmented into P1a, P1b, and N1 microstates using map rather than channel features. Map latencies, amplitudes and sources were tested for bilateral interactions. Bilateral targets yielded shorter VEP map latencies but later response onsets than unilateral ones. Source analyses of the unilateral VEPs indicated a transition from contra- (P1a) to ipsilateral (P1b) visual cortex activation (interhemispheric transfer). Bilateral VEPs were smaller than the summed unilateral VEPs in all microstates. indicating that interhemispheric interactions both precede and follow interhemispheric transfer. Brain mapping of uni- and bilateral VEPs in children thus revealed several distinct forms of interhemispheric interactions in the same, early time range.     

Spectral Analysis of the Visual Evoked Potential (VEP): Effects of Stimulus Luminance

Power spectral analysis was performed on the visual evoked potentials (VEPs) of subjects who had participated in an augmenting-reducing study. Six flash luminances were used (0.31, 0.65, 1.25, 2.5, 5.0, and 10.0 fL). EEG recordings were taken from C_z O₁, O₂, T₃, and T₄ scalp locations. Power in six frequency ranges was examined (0–2, 2–6, 6–10, 10–14, 14–18, and 18–22 Hz). Power in the lowest three frequency ranges increased linearly with stimulus luminance at all electrode sites. Power in the highest three ranges increased linearly with luminance at occipital sites only. Power was greater in the left hemisphere than in the right for 18–22 Hz activity recorded at occipital locations. The reverse asymmetry occurred for 6–14 Hz activity recorded at temporal locations. The results suggest that individual differences in stimulus control in EEG recordings taken from scalp locations overlying nonspecific cortex are due primarily to the contributions of higher frequency components of the VEP spectrum. A thalamo-cortical model of stimulus control is described.     

非枕叶癫痫患者视觉诱发电位的表现

目的：研究非枕叶癫痫患者视觉传导通路可能的损害及其机制.方法：应用诱发电位仪对非枕叶癫痫中的难治性癫痫患者（第一组）、非枕叶癫痫中的非难治性癫痫患者（第二组）及健康志愿者（第三组）共3组进行视觉诱发电位（VEP）检测,观察其N75波潜伏期（LN75）、P100波潜伏期（LP100）、N75波幅（AN75）、P100波幅（AP100）等指标.结果：第一、二组的LN75、 LP100均较第三组延长,差异有统计学意义（P〈0.05）,而第一、二组间的LN75和LP100比较差异均无显著意义（P〉0.05） 第一组的AP100较第三组升高,差异有统计学意义（P〈0.05）,而第一、二组间比较差异无显著意义（P〉0.05） 三组间比较AN75比较差异均无统计学意义（P〉0.05）.结论： 非枕叶癫痫患者存在视觉传导异常,表现为LN75、LP100延长,AP100的升高 而其中的难治性癫痫患者与非难治性癫痫患者的视觉传导异常程度比较差异无统计学意义.     

The Effects of Stimulus Expectancy on Evoked Brain Potentials

The effects of self-generated expectancy of stimulus content on the visual evoked potential to physically identical stimuli were studied in college students. The subject set up his own internal expectant; by choosing to see either a bright or dim Hash. When a bright or dim Hash was anticipated, the potentials evoked by u medium stimulus intensity resembled the responses elicited by an actual bright or dim flash, respectively. Significant differences in visual evoked potential amplitude were obtained between identical medium intensity stimuli depending on the stimulus intensity expected, despite (he constant physical properties of the stimulus. 1 In1 results suggest that a subject's expectancy of certain physical parameters of a stimulus are as important In determining (he resultant visual evoked potential as the actual physical features of the stimulus.     

视觉、脑干听觉诱发电位对多发性硬化的诊断价值

目的 :探讨视觉诱发电位 (VEP)、听觉诱发电位 (BAEP)对多发性硬化 (MS)的诊断价值。方法 :对 30例临床诊断为MS的患者进行VEP、BAEP检测 ,并与正常对照组进行比较分析。结果 :MS患者VEP和BAEP的异常率分别为 73%和 6 0 %。异常中VEP有 6 8% ,BAEP有 78%的患者 ,临床有相应的症状 ;VEP 32 % ,BAEP 2 2 %的患者临床无相应症状。 5例MS患者在临床缓解期复查VEP、BAEP ,1例VEP、BAEP恢复正常 ,4例仍异常。结论 :VEP、BAEP检测对MS的诊断具有重要意义。     

焦虑症患者VEP及AEP临床研究

目的：观察焦虑症患者听觉诱发电位(AEP)及视觉诱发电位(VEP)的特点。方法：对30例符合CCMD-Ⅱ-R诊断标准的焦虑症患者进行VEP和AEP检查，并以30例正常人作对照。结果：VEP在Fz及Cz处的P2、P3波幅明显降低，在Cz处N1潜伏期延长；AEP在Cz及P2处的P2、P3波波幅明显降低，N1潜伏期延长，在Cz处P2潜伏期延长。结论：焦虑症患者的VEP、AEP有波幅降低，潜伏期延长。     

Detection and Processing of Individual Components in the VEP

This paper describes a new technique for use in the field of evoked potentials research. The technique makes use of the latency corrected average method for identification of the components of the single evoked potential. Examples are presented in which this technique is utilized to separate homogeneous subsets of potentials within a set of tests.     

精神运动性癫痫患者脑诱发电位初步观察

目的研究脑诱发电位在精神运动性癫痫病人的应用。方法应用诱发电位仪对１６例精神运动性癫痫的听觉诱发电位（ＡＥＰ）、视觉诱发电位（ＶＥＰ）和听觉事件相关电位（听觉Ｐ３００）作了检测，并与正常对照组进行了比较。结果患者组波形变异大，潜伏期ＡＥＰ的Ｐ２、Ｐ３，ＶＥＰ的Ｎ１、Ｐ２以及Ｐ３００靶刺激的Ｐ２、Ｎ２均延迟，非靶刺激的Ｎ１前移。波幅ＡＥＰ的Ｐ２、ＶＥＰ的Ｐ２、Ｐ３降低，与正常对照组有显著性差异。结论ＢＥＰ技术可作为脑电图检查的一种补充手段，以便临床参考诊断此类病征。     

Occipital cortex activation studied with simultaneous recordings of functional transcranial Doppler ultrasound (fTCD) and visual evoked potential (VEP) in cognitively normal human subjects: Effect of healthy aging

We evaluated effect of aging, gender and eye (sighting) dominance on relationship between visual evoked flow response (VEFR) and visual evoked potential (VEP), which refers to neurovascular coupling. The VEFR was defined as a percentage increase of the ratio of mean blood flow velocity in the contralateral (according to the side of dominant eye processing) posterior cerebral artery P2 segment to those in ipsilateral middle cerebral artery from the baseline during half-field stimulation. Vasoneural coupling index (CI) was defined as “100 × VEFR/VEP P100 amplitude”. Compared to the healthy elderly subjects (n: 19; female/male: 6/13, mean age: 69.7 ± 7), younger participants (n: 28; female/male: 16/12; mean age: 31.1 ± 4.7) had significantly higher VEFR for both sides: 18.9 ± 6.7% versus 11.2 ± 6.7%, p < 0.001 and 17.3 ± 7.7% versus 11.8 ± 5.5%, p: 0.007, for the hemisphere contralateral to dominant and nondominant eye (D and ND side), respectively. Albeit absence of any correlation between their latencies, VEP and VEFR amplitudes were well correlated. However, this was significant only for younger subjects and more evident in D side. The CI was higher in young subjects compared to those in old ones (6.49 ± 2.79 versus 4.75 ± 2.35, respectively, p = 0.007). But, this age-related trend remained as borderline when sides were analyzed individually: In the young subjects CI was 5.99 ± 2.21 and 6.96 ± 3.22 for D and ND sides, while those were 4.27 ± 2.60 and 5.19 ± 2.07 in old ones. This study confirmed diminished visual evoked flow in relation with advancing age, and suggested that “weakened” neurovascular coupling (as evidenced by a decreased VEP and VEFR correlation along with decreased CI) as one of the underlying mechanisms.