眼挫伤后视力损害患者视觉诱发电位分析

目的:探讨视觉诱发电位(VEP)在评价挫伤后视力损害中的价值。方法:对74例挫伤性视力损害患者进行图形翻转刺激VEP测定,并与自体健侧眼和正常对照组进行比较。结果:74例患者中,单眼挫伤57例,双眼挫伤17例,共91眼受伤,受伤眼均有不同程度视力损害。VEP检查结果:91 眼中波形不典型者5眼(6％);P100波幅下降异常者54眼(59％);P100潜伏期延长者23眼(25％)。其中单纯潜伏期延长12眼(13％);单纯波幅下降异常43眼(47％);潜伏期延长伴波幅下降者11眼 (12％),总异常66眼,异常率为73％。所有挫伤后视力损害者,与自体健侧服和正常对照组比较,P100 潜伏期延长和波幅降低,差异均有显著意义(P<0．01)。结论:VEP为挫伤性视力损害的视功能评价、临床早期诊断、预后评估以及伤残鉴定提供了重要的客观依据。     

眼外伤性视神经挫伤患者的早期视觉诱发电位分析

目的 :探讨视觉诱发电位 (VEP)在眼外伤性视神经挫伤中的应用价值。方法 :对 6 8例临床诊断为外伤性视神经挫伤的患者进行VEP测定 ,并与自体健侧眼或正常对照组进行对照。结果 :6 8例患者中单眼挫伤者 6 2例 ,双眼挫伤者 6例 ,共 74眼 ,VEP检查结果均有不同程度的异常。其中有 2例 3眼VEP波幅明显降低 (4 % ) ,单纯波幅异常降低者 5 0例 5 3眼 (71% ) ,波幅降低伴有峰潜伏期延长者 16例 18眼 (2 5 % )。所有外伤性视神经挫伤与自体健侧眼和正常对照比较 ,P10 0波幅差异有显著意义 (P <0 0 1) ,而P10 0峰潜伏期仅有 16例稍有延长 ,与正常值比较无明显差异 (P >0 0 5 )。结论 :VEP对眼球钝挫伤后视神经损伤的检出有较高的敏感性 ,因此对于眼外伤性视神经挫伤中的早期诊断 ,疗效观察 ,预后评估有着重要价值     

视觉诱发电位对眼挫伤患者的应用价值

目的:探讨视觉诱发电化(VEP)对眼挫伤视神经损伤的诊断、预后评估和出具鉴定意见的价值。方法:对55例眼挫伤患者(单眼挫伤53例,双眼挫伤2例)进行VEP检查,单眼损伤者以自体健侧眼为对照。视力≥0.1者行图形模式刺激视觉诱发电位(P-VEP)检查为A组;视力<0.1者行闪光视觉诱发电位(F-VEP)检查为B组。结果:55例中VEP正常16例(占29%),异常39例(占71%)。异常者中单纯P100波幅下降9例(占23%),单纯P100波潜伏期延长12例(占31%),P100波潜伏期延长伴波幅下降16例(占41%),P100波形完全消失2例(占5%)。所有眼挫伤后视力损害者与自体健侧眼作对比,A、B组间VEP P100波潜伏期延长和波幅降低,差异均有非常显著意义(P<0.01)。结论:VEP为挫伤性视力损害的视功能评价、临床早期诊断、预后评估以及伤残鉴定提供了重要的客观依据。     

视觉诱发电位与优势眼

目的:研究正常儿童优势眼视觉诱发电位特征。方法:对47名正常儿童进行全视野刺激多导视觉诱发电位研究。结果:优势眼视觉诱发电位以0_z电极为代表,P_(100)潜伏期较非优势眼缩短(P<0.01),而N_(75)—P_(100)峰峰值较非优势眼增大(P<0.05)。结论:中枢神经系统存在偏利现象,这种偏利现象可能与控制视神经髓鞘优先形成的某种遗传机制有关,或是中枢神经系统突触的局部构造、突触效能的差异。     

挫伤性近视治疗前后视觉诱发电位的临床分析

目的：（１）探讨挫伤性近视治疗前后视觉诱发电位的幅值及潜时变化特征；（２）探讨复方樟柳碱治疗的临床效果。方法：采用重庆大学医电仪器公司产ＡＶＳ－１０００视觉电生理仪，对挫伤性近视患采用分组测量。结果：（１）治疗前Ｐ－ＶＥＰ Ｐ１００波幅值降低，潜时延长；（２）配镜矫正后Ｐ１００波潜时仍延长，而振幅幅值升高明显；（３）治疗组治疗后潜时明显缩短；幅值明显升高，对照线与治疗组比较，二行ｔ检验差异非常     

视觉眼电生理在视网膜挫伤中的应用

86例86眼视网膜挫伤患者经过视觉眼电图检查。异常率81例(94％)。异常改变主要表现为光峰电位降低或者光峰电位和暗谷电位一致降低。患者Arden比有变化,部分降低,部分正常,部分增高。光峰电位降低幅度超过100Nu者63例(78％)。光峰电位降低幅度与视力变化受检时间和视网膜挫伤程度均无显著性差异。在诊断方面,EOG的价值与ERG和FFA作了对比。异常EOG和病理所见的视细胞损害相吻合。本文还对外伤性白内障、玻璃体积血和视神经挫伤的EOG检查进行了探索。     

视觉诱发电位,视网膜电图及眼电图的临床应用进展

现代科学研究表明至少有70％的外界信息是通过视觉系统被接受、分析和处理的。在视觉信息的处理和加工过程研究中占重要地位的是神经电活动。目前视觉电生理研究已拓展为神经生物学中取得长足进展的领域。视网膜是神经系统的外周感受器中了解得最清楚的区域之一;而对视皮层细胞结构和功能的研究远较大脑其它区域更为深入和清楚。随着视觉电生理的不断发展,越来越多的研究方法逐渐应用于眼科临床。如视觉诱发电位(Visual Evoked Potential,VEP)、视网膜电图(Electroretinograph,ERG)、眼电图(Electrooculargram,     

帕金森病患者视觉诱发电位地形图改变及意义

目的：探讨帕金森病（PD）患者视觉传导通路功能受累的可能性及视觉诱发电位（VEP）空间分布特征。方法：应用VEP-脑地形图对20例PD患者与24位正常人进行对比研究。结果：（1）PD患者P1、N2波潜伏期延长;（2）两眼间潜伏期差增大;（3）颅顶波幅值呈广泛性降低,以左半球为著。结论：PD患者视觉信息在时间和空间传导中均发生障碍,VEP-脑地形图可敏感地反映出这种改变,对PD的研究及临床诊断,疗效观察均有一定价值。     

自适应干扰对消的大鼠视觉诱发电位提取

研究大鼠的视觉诱发电位对认知人类视觉机理和疾病发生的位置具有重要意义.为获得大鼠视觉刺激诱发电位的特征信息,本研究设计了一种新的用于自适应干扰对消的大鼠视觉诱发电位信号采集方案,在大鼠初级视皮层不同位置和深度分别植入检测电极和干扰参考电极,有效提取了同源干扰信号.并基于该方案进行了大鼠视觉诱发电位的快速提取研究.仿真实验和实际应用结果表明,应用该方案实现自适应干扰对消,信噪比提高约6 dB,能够有效提取出大鼠单次闪光刺激诱发电位波形,并可从单次提取的结果中获得准确的潜伏期信息.该方案为实时获取大鼠视觉诱发电位特征信息提供了有效手段.     

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     

Pattern visual evoked potentials in the rat

Pattern and flash visual evoked potentials (VEPs) were obtained in 25 adult male hooded rats. Different electrode placements were used to detect the origin of the VEPs. The spatial frequency and temporal modulation of the stimulating pattern and the refractive state of the eye were varied to investigate the specificity of these factors in pattern VEPs. Variations in latency, amplitude, and trace morphology were found which were consistent with the characteristics of the visual system of the rat.     

Investigation of evoked potentials to photic stimulation in man after deafferentation of the visual cortex

Evoked potentials (EPs) to photic stimulation in the occipital cortex were investigated in 28 patients with homonymous hemianopia caused by a focal lesion of the visual system. Asymmetry of the EPs in the two hemispheres was recorded only in cases of complete homonymous hemianopia. A reduction in the response on the side contralateral to the hemianopia was observed in patients with lesions of the visual pathways at the level of the optic tract and as a result of the spread of the pathological focus to the occipital lobe. In patients with a lesion affecting predominantly the mediobasal zones of the temporal lobe and with homonymous hemianopia caused by a lesion of the optic radiation, responses in half of the cases were higher in amplitude on the side of the focus or were recorded only in the deafferented occipital region.N. N. Burdenko Institute of Neurosurgery, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. I. Arutyunov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 79, No. 4, pp. 23–26, April, 1975.     

Objective measurement of human visual acuity by visual evoked potentials

Electrophysiological studies were performed to measure the threshold (upper end of range) spatial frequency using visual evoked potentials and comparison with visual acuity neuron 26 healthy subjects. The aim of the present work was to create a method for objective measurement of visual acuity. This was addressed by initial measurements using a universally accepted method of visual stimulation and processing of electroencephalograms, which allows errors due to individual differences in visual system function to be minimized. These experiments yielded a strong correlation between the threshold spatial frequency of the test grid yielding an evoked potential on presentation and visual acuity, in degrees, expressed as the resolving ability of the visual system for this optotype. A logarithmic relationship was found between these values and an equation allowing automated calculation of visual acuity (resolving ability) from electrophysiological data was derived. The results were independent of the subject’s responses and therefore provides a maximally objective assessment of visual acuity. __________ Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 91, No. 8, pp. 956–969, August, 2005.     

Effect of chronic undernutrition and/or visual deprivation upon the visual evoked potential from the developing rat brain

Maturation of the visual evoked potential and the response of the visual cortex to increasing frequencies of light stimulation were studied across seven ages (12, 13, 14, 16, 20, 30, and 45 days) in the albino rat. The age groups were further divided into four treatment groups: control (C), undernourished (U), visually deprived (VD), and visually deprived/undernourished (VD/U). The younger ages (12–16 days) differed from the older ones (20–45 days) as to latency time for the first positive, first negative, and second positive wave components. Control rats differed from U and VD/U through 16 days for the first negative wave and through 14 days for the first positive and second positive waves. No differences were seen after 20 days. All C animals responded to rapid frequency of flash stimulation by 30 days; VD responded by 45 days. No significant changes in the ECoG were seen in any environmental group after 20 days. Histology (dendrite, Nissl, and myelin) revealed little supportive evidence as to gross changes in the visual cortex, suggesting that subcortical visual structures were more affected by environmental manipulation. Results are discussed in the terms of various physiological defects.     

Effects of selective visual attention in the parietal and temporal areas of the human cortex using evoked potential data

Studies of 11 young subjects addressed the analysis of evoked potentials in the parietal and temporal areas to sequential presentation of visual symbols on the left and right sides; symbols were squares and circles and were observed passively and in conditions of selective attention to target stimuli presented to the subjects in random order and requiring rapid and precise motor responses. Comparison of monopolar evoked potentials in leads P3, P4, T3, T4, T5, and T6 with bipolar potentials in leads P3-T3, P3-T5, P4-T4, and P4-T6 in conditions of passive and selective attention showed that voluntary attention was accompanied by significant rearrangements in evoked activity in the parietal and temporal areas. This was evident as: 1) an increase in correlations between evoked potentials in the parietal and temporal areas; 2) stabilization of monopolar evoked potentials over time, i.e., increases in the correlations of sequential evoked potentials, in both associative visual areas; 3) stabilization of bipolar parietal-temporal evoked potentials in terms of increases in their sequential correlations. It is suggested that selective attention facilitates linked activity of the two associative areas, which is needed for performance of visual selection.Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 89, No. 7, pp. 776–785, July, 2003.     

兔脑缺血的视觉和听觉诱发电位的变化

阻断兔双侧椎动脉（ＢＶＡ）和左颈总动脉（ＬＣＣＡ）后，夹闭右颈总动脉（ＲＣＣＡ）３、５、７ｍｉｎ，松开ＲＣＣＡ再灌流，记录听觉脑干诱发电位（ＢＡＥＰｓ）、中潜伏期听觉诱发电位（ＭＡＥＰｓ）以及视觉诱发电位（ＶＥＰｓ）。发现不全阻断脑血流后２．５ｍｉｎ，ＭＡＥＰｓ Ｎ０消失；４．５ｍｉｎ，ＶＥＰｓ Ｎ１和Ｐ２消失，ＢＡＦＰ３ Ⅰ～Ⅴ波峰值潜伏期延长，而振幅无明显变化。完全阻断脑血流１．５ｍｉｎ，ＶＥ     

Effects of stimulus orientation on spatial frequency function of the visual evoked potential

Visual performance is better in response to vertical and horizontal stimuli than oblique ones in many visual tasks; this is called the orientation effect. In order to elucidate the electrophysiological basis of this psychophysical effect, we studied the effects of stimulus orientation on the amplitudes and latencies of visual evoked potentials (VEPs) over different spatial frequencies of the visual stimulation. VEPs to sinusoidal gratings at four orientations (vertical, horizontal, and oblique at 45 degrees and 135 degrees) with eight spatial frequencies (0.5-10.7 cycles/deg) at reversal rates of 1 Hz and 4 Hz were recorded in nine subjects. At 1-Hz stimulation, the amplitude and latency of P100 were measured. At 4-Hz stimulation, VEPs were Fourier-analyzed to obtain phase and amplitude of the second harmonic response (2F). At 1-Hz stimulation, P100 latencies were decreased for oblique stimuli compared with those for horizontal and vertical stimuli at lower spatial frequencies. Conversely, those for oblique stimuli were increased compared with those for horizontal and vertical stimuli at higher spatial frequencies. At 4-Hz stimulation, spatial tuning observed in 2F amplitude of the oblique gratings shifted to lower spatial frequencies when compared with those of vertical stimulation. The alteration of the VEP spatial frequency function caused by the oblique stimuli was in good agreement with the orientation effect observed in psychophysical studies. Our study may have a clinical implication in that VEP testing with stimuli in more than one orientation at slow and fast temporal modulations can be useful in evaluating neurological disease affecting the visual system.