不同刺激野的视觉诱发电位（P-VEP）的研究

发布时间：2018-05-09 00:19

本文选题：视觉诱发电位 + 视野　；参考：《中国医科大学》2008年硕士论文

【摘要】： 目的视觉(vision)主要包括光觉、色觉和形觉,它是人感受外界的重要功能之一。其中形觉包括视力和视野二个方面。由于被鉴定人特殊的心理作用,常常夸大或伪装视功能障碍,使主观性较大的临床视野检查法难以应用于临床法医学鉴定中。因此,如何客观的评定视野状态是临床法医学重要的研究课题之一。视觉诱发电位(Visual evoked potential,VEP)是通过对视网膜进行刺激,经过视路传送在枕叶视皮层所诱发的电活动。反映了从视网膜神经节细胞到视皮层的功能状态。VEP分为闪光视觉诱发电位和图像视觉诱发电位(Patten Visualevoked potential P—VEP),以P—VEP应用最为广泛。P—VEP主要由负相波N_(75)(negative response 75)、正相波P_(100)(positive response 100)和负相波N_(145)(negativeresponse 145)三相复合波组成。其中P_(100)在所有健康人各个空间频率的刺激中均能记录到,正常变异小,稳定可靠,故本试验主要以P_(100)为观察值。P—VEP是临床医学和法医学鉴定中对视功能客观评定的重要方法,以往研究认为不同刺激野P—VEP存在差异。研究不同刺激野P—VEP的特征将具有重要的法医学意义。本研究采用多通道记录电极,分别置于30名(60眼)正常视功能者O_z、O_1、T_5、T_3、O_2、T_6、T_4、Pz、Oz、Iz点及自设点X。对不同刺激野进行刺激以诱发P—VEP,研究各刺激野P—VEP在Oz点P_(100)的正常潜伏期、波幅、波形特征及其相互之间的关系以及P—VEP在枕颞部不同部位电场分布特点,以期为探索视野功能的客观评定方法提供基础依据。对象与方法主观检查配合的受试者30名(60眼),男性和女性各15名,年龄范围21—26岁,平均年龄23岁,均为中国医科大学在校学生。筛选标准:矫正视力均≥1.0,主观视野检查均在正常范围内(手动视野计检查法)。试验方法:采用上海海神(NDI-200P+)多功能电生理记录仪,刺激器视屏大小为17′,选用视角30′及1°的翻转黑白棋盘格作为刺激信号。刺激频率3Hz,对比度与亮度调至显示器80%固定。带通滤波设定为1～100Hz,扫描时间为300ms,叠加次数为100次。采用四通道记录法对多个记录点分别记录不同刺激野P—VEP,电极为银-氯化银盘状皮肤电极,按国际10-2脑电图记录系统,记录电极分别置于Oz点(枕骨粗隆点向上3.0cm)、O_1点(Oz点向左旁开2.0cm)、T_5点(Oz点向左旁开5.0cm)、T_3点(Oz点向左旁开10.0cm)、O_2点(Oz点向右旁开2.0cm)、T_6点(Oz点向右旁开5.0cm)、T_4点(Oz点向右旁开10.0cm)、Pz点(Oz点向上5.0cm)、Iz点(枕骨粗隆点)、自设点X点(Iz点向下2.0cm),接地电极置于手腕部,参考电极置于Fz点(鼻根上12.0cm)。各电极阻抗＜5kΩ,电极间电阻相差＜3kΩ。受试者眼在自然瞳孔状态下,距刺激器视屏1.15米并与刺激器处于同一水平线,遮盖单眼,嘱被检眼注视刺激器注视点,记录Oz、O_1、T_5、T_3、O_2、T_6、T_4点(其中Oz、O_1、O_2为正中组电极)在下列刺激野P—VEP结果:中央全屏刺激野(16°刺激野)、左/右半刺激野(8°及16°刺激野)中央中心屏刺激野(中央8°刺激野)、左/右半中心刺激野(4°刺激野)和左/右旁中心刺激野(8°及16°视野中去除4°视野)。变换电极记录点为Pz、Oz、Iz及自设点X后,记录中央全屏刺激野、上全屏刺激野及下全屏刺激野P—VEP结果。采用四通道记录法对多个记录点分别记录不同刺激野P—VEP,测试时间约40s,每次测试间隔2-3分钟,让被测眼休息,以消除视疲劳。结果 1、正常人上全屏刺激野、中央全屏刺激野与下全屏刺激野的P—VEP结果: 给予上、下全屏刺激野及中央全屏刺激野刺激,各记录点P_(100)潜伏期为:下刺激野＜全刺激野＜上刺激野;波幅为:上刺激野＜下刺激野＜全刺激野。不同记录点间各刺激野P_(100)潜伏期比较:X点＜Iz点＜Pz点＜Oz点;波幅:X点＜Iz点＜Pz点＜Oz点。中央全屏刺激野及下全屏刺激野所诱发VEP波形较上全屏刺激野刺激诱发的波形规整、波幅大易分辨,且下部电极记录到的上刺激野诱发VEP有15.83%出现位相倒转。在Pz点可在各刺激野条件下记录到P—VEP,虽波幅较Oz点低,特别是上刺激野条件下Pz点记录到的波幅最低,但Pz点P—VEP波形光滑、干扰小。 2、正常人中央全屏刺激P_(100)波分布: 给予正常人在中央全屏刺激野刺激,双侧对应记录点记录到的P—VEP波形对称一致,各记录点P_(100)潜伏期及波幅与记录点距Oz点距离呈负相关。即比较相同中央刺激野诱发P—VEP:中央部电极记录到P—VEP波幅最大,潜伏期最长。随着记录点与Oz点距离的增加,所得P—VEP波幅逐渐降低,潜伏期亦逐渐缩短。 3、正常人左、右半刺激野P—VEP结果: 半视野刺激的VEP幅度较低,在头顶呈明显的不对称的分布,刺激野同侧的VEP波形较恒定,为N-P-N复合波。刺激野对侧的VEP波形较复杂,变异大。本试验主要表现为四种类型:①刺激野同侧出现N-P-N波,对侧无可辨认的VEP成份;②刺激野同侧出现N-P-N波,对侧有位相倒转的P-N-P波;③刺激同侧为N-P-N波,对侧VEP呈部分相倒转状;④刺激野同侧为N-P-N波,对侧亦呈N-P-N复合波在侧半视野刺激时:刺激野同侧电极均记录到N-P-N复合波,中央部电极亦为N-P-N复合波。刺激野对侧电极记录到的P—VEP波形中,约7.1%无法辨认;约12.92%出现倒转复合波或部分倒转复合波;约79.98%出现N-P-N复合波。在旁半视野刺激时:刺激野同侧记录点有11.94%记录到无法辨认的复合波,88.06%为N-P-N复合波,中央部电极可与刺激野同侧相同,亦可与刺激野对侧相同。刺激野对侧记录点有14.58%记录到N-P-N复合波,43.06%记录到P-N-P复合波,42.36%记录到无法辨认的P—VEP波形。 4、鼻、颞侧刺激野VEP结果: 与颞侧刺激野刺激产生的波形相比,中央刺激野刺激产生的VEP波形与鼻侧刺激野刺激产生的波形更相似。双眼鼻侧刺激野与颞侧刺激野比较,P_(100)潜伏期具有统计学差异,鼻侧刺激野较颞侧刺激野P_(100)潜伏期延长3.9±1.2ms。双眼间相同刺激野比较,P_(100)潜伏期无统计学意义。 5、中央全屏与中央中心屏刺激野VEP结果: 全屏16°刺激野与中央8°刺激野比较P_(100)潜伏期无统计学差异,全屏刺激野与中央刺激野比较P_(100)波幅显著增高,具有统计学意义。 6、侧半刺激野、侧半中心刺激及侧半旁中心刺激野VEP结果: P_(100)潜伏期:侧半中心刺激野≈侧半刺激野＜侧半旁中心刺激野。P_(100)波幅:侧半旁中心刺激野＜侧半中心刺激野≈侧半刺激野。结论 1、正常人上刺激野、中央刺激野和下刺激野P—VEP潜伏期及波幅存在差异,Pz、Oz、Iz和自设点X在相同刺激条件下记录的P—VEP存在差异。Iz和自设点X对记录上刺激野诱发P—VEP较稳定。 2、中央全屏诱发VEP波随记录点不同存在差异,水平及垂直方向随着与Oz点距离增加,P100波幅逐渐减小。 3、不同半刺激野诱发VEP波在水平各记录点记录波存在差异。于刺激野同侧记录点可较稳定记录到VEP波,于对侧可记录到特异的VEP波。 4、各种半刺激野中,包含中心刺激的P—VEP诱发率高。在不含中心刺激的旁中心刺激野P—VEP中,增加刺激野面积或适当增大刺激视角可提高P—VEP检出率。
[Abstract]:objective
Vision mainly includes light, color and shape perception. It is one of the most important functions of people to feel the outside world. It includes two aspects of vision and vision. Due to the special psychological function of the identified person, it is often exaggerated or disguised as the visual dysfunction, so the subjective clinical field examination method is difficult to apply to the clinical forensic identification. Therefore, how to evaluate the state of vision objectively is one of the important research topics in clinical forensic science.
Visual evoked potential (VEP) is an electrical activity induced by the optic pathway through the retina, which reflects the functional state of the retinal ganglion cells to the visual cortex, which is divided into the flash visual evoked potential and the image visual evoked potential (Patten Visualevoked potential P V). EP), with P - VEP, the most widely used.P - VEP is composed mainly of negative phase wave N_ (75) (negative response 75), positive phase wave P_ (100) (positive response 100) and negative phase wave N_ (145) (145) (145) three phase composite waves. P_ (100) as an observation value of.P - VEP is an important method for objective evaluation of visual function in clinical and forensic forensic studies. Previous studies suggest that there is a difference between P and VEP in different irritation fields. The study of the characteristics of P VEP in different irritation fields will have important forensic significance.
In this study, a multichannel recording electrode was used in 30 (60 eyes) normal visual functions, O_z, O_1, T_5, T_3, O_2, T_6, T_4, Pz, Oz, Iz points, and self point X. to stimulate the different stimulus fields to induce the P to be induced, and to study the positive latency, amplitude, waveform characteristics and the relationship between the stimuli field (100). The distribution characteristics of electric field in different parts of occipital temporal region, in order to provide a basis for exploring objective assessment methods of visual field function.
Object and method
30 subjects (60 eyes) with subjective examination, 15 men and women each, age range from 21 to 26 years old and average age 23 years old, were all students at China Medical University. The screening criteria: corrected visual acuity was equal to 1, and the subjective field of vision was within the normal range (manual perimeter examination).
The test method: the Shanghai sea god (NDI-200P+) multi-function electrophysiological recorder was used. The size of the stimulator screen was 17 ', the angle 30' and 1 degree turned black and white checkerboard was used as the stimulus signal. The stimulation frequency was 3Hz, the contrast and brightness were adjusted to the display 80%. The bandpass filter was set to 1 to 100Hz, the scanning time was 300ms, and the number of superposition times was 100 times.
The four channel recording method was used to record the different stimulation fields P - VEP, and the electrode was silver chloride silver disk like skin electrode. According to the international 10-2 electroencephalogram recording system, the recording electrodes were placed at Oz point (occipital roughing point up 3.0cm), O_1 point (Oz point to left side 2.0cm), T_5 point (Oz point to left 5.0cm), T_3 point (10 Oz points to left side open to left side 10). .0cm), O_2 point (Oz point to right side 2.0cm), T_6 point (Oz point to right side open 5.0cm), T_4 point (Oz point to right side 10.0cm), Pz point (Oz point upward), self point point (point downward), grounding electrode placed in the wrist, reference electrode placed on the nose root (nose root). In the natural pupil of the subjects, the subjects were 1.15 meters from the stimulator screen and placed on the same horizontal line with the stimulator, covering the monocular and being asked to look at the fixator of the stimulator, recording Oz, O_1, T_5, T_3, O_2, T_6, T_4 points (Oz, O_1, O_2 as the median electrode) in the lower column stimulated wild P VEP results: the central full screen stimulation field (16 degree stimulation field), left / right The central central screen stimulation field in the semi irritant field (8 and 16 degrees irritation field), the central 8 degree stimulation field, the left / right semi central stimulation field (4 degree stimulation field) and the left / right paraplastic central stimulation field (8 degrees and 16 degrees in the field of vision). The recording points of the transform electrode are Pz, Oz, Iz and self set X, and the central full screen stimulation field is recorded, and the full screen stimulus field and the lower full screen stimulation field P are recorded. VEP results. The four channel recording method was used to record the different stimulation fields P VEP respectively. The test time was about 40s and the interval of each test was 2-3 minutes, so that the eye was rest to eliminate visual fatigue.
Result
1, the full screen stimulation field on the normal subjects, the P VEP results of the central full screen stimulation field and the whole screen stimulus field:
At the top of the full screen stimulation field and the central full screen stimulation, the P_ (100) incubation period of each record point was: the lower stimulation field was "all irritation field", and the amplitude was: the upper stimulation field was less than the whole irritation field.
The latency of P_ (100) between different recording points was compared: X point < Iz point < Pz point < Oz point; amplitude: X point < Iz point < Pz point < Oz point.
The VEP waveforms induced by the central full screen stimulation field and the lower full screen stimulation field are more sensitive to the waveform regulation induced by the full screen stimulation field stimulation. The amplitude of the wave amplitude is easily resolved, and the VEP in the upper stimulus field recorded by the lower electrode has 15.83% phase inversion. At the Pz point, the P VEP can be recorded in the stimulus field, although the amplitude is lower than that of the Oz point, especially the upper stimulus field. Under the condition, the Pz points recorded the lowest amplitude, but the Pz point P - VEP waveform is smooth and the interference is small.
2, the P_ (100) wave distribution was stimulated by the central full screen of normal people:
The normal people were stimulated by the central full screen stimulation field, and the P VEP waveform recorded by the bilateral corresponding record points was the same. The P_ (100) latency and amplitude of each recording point were negatively correlated with the distance from the Oz point. That is, the same central stimulation field induced the P VEP: central electrode to record the maximum amplitude of P VEP and the longest incubation period. With the record, the recording point was the longest. The increase of the distance from the Oz point to the P point decreases the amplitude of the VEP - wave.
3, left and right half - stimulation field P - VEP results in normal people:
The VEP amplitude of the half field stimulation was lower, the distribution of the VEP waveform in the irritation field was more constant and the N-P-N complex wave was more constant. The VEP wave in the opposite side of the stimulation field was more complex and varied. The main manifestations of this experiment were four types: (1) the N-P-N wave in the irritation field of the wild, the non identifiable VEP component in the opposite side; The present N-P-N wave has a phase inversion of P-N-P wave on the opposite side; (3) the stimulation of the same side is the N-P-N wave and the opposite side VEP is partially reversed; (4) the stimulation of the same side is N-P-N wave, and the opposite side is also a N-P-N complex wave.
In the side half field stimulation, the stimulated field ipsilateral electrode recorded the N-P-N complex wave and the central electrode was also N-P-N complex wave. About 7.1% could not be identified in the P VEP waveform recorded by the field to side electrode; about 12.92% appeared reversed complex wave or partial inversion complex wave, and about 79.98% appeared N-P-N complex wave.
In the side half field of vision stimulation, the stimulation field is 11.94% to the unrecognizable complex wave, 88.06% is the N-P-N complex wave, the central electrode can be the same as the irritating field, and the same to the irritating field. The stimulation field is 14.58% to the N-P-N complex wave, 43.06% to the P-N-P complex wave, and 42.36% to the impossible. Identified P - VEP waveform.
4, nasal, and temporal stimulation of the wild VEP results:
Compared with the waveform generated by temporal stimulation field stimulation, the VEP waveform generated by the central stimulation field is more similar to the waveform generated by the stimulation on the nasal side.
Compared with the temporal irritation field in the binocular lateral irritation field, the latent period of P_ (100) was statistically different, and the P_ (100) latency of the nasal irritation field was longer than that of the temporal irritation field (100), which was 3.9 + 1.2ms. between the two eyes, and the latency of P_ (100) was not statistically significant.
5, central full screen and central central screen stimulation field VEP results:
There was no statistical difference in the latent period of P_ (100) in the full screen 16 degree stimulation field and the central 8 degree stimulation field. The P_ (100) amplitude of the full screen stimulation field and the central stimulation field increased significantly, with statistical significance.
6, the side semi stimulation field, lateral semi central stimulation and lateral para center stimulation field VEP results:
The latent period of P_ (100): the lateral semi central stimulation field semi irritant wild.P_ (100) wave amplitude in the lateral paralateral central stimulation field: the side half central stimulation of the wild semi central irritation field.
conclusion
1, there are differences in the latent period and amplitude of P - VEP in the normal human stimulation field, the central stimulation field and the lower stimulation field. The P - VEP, the Pz, Oz, Iz and self - set X, recorded in the same stimulus conditions, the.Iz and the self - set X are stable to the P VEP.
2, the central full screen induced VEP wave is different from the recording point. The P100 amplitude decreases with the increase of Oz distance in horizontal and vertical directions.
3, there is a difference in the recording of the VEP wave at the level of the horizontal recording point induced by different semi irritant fields. The VEP wave can be recorded steadily at the ipsilateral recording point of the irritant field, and the specific VEP wave can be recorded on the contralateral side.
4, in various semi irritant fields, the rate of P - VEP, which contains central stimulation, is high. In the paracenter P - VEP without central stimulation, the increase of the area of the stimulation field or the appropriate increase of the stimulus angle can increase the detection rate of P VEP.

【学位授予单位】：中国医科大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：D919;R77

【引证文献】