阿尔茨海默病与脑血管病痴呆患者的诱发电位比较研究

目的：观察阿尔茨海默病痴呆（AD）和脑血管病痴呆（VD）视觉及听觉诱发电位的特点。方法：收集25例AD组、24例VD及22名正常老年人（NC），完成听觉诱发电位（AEP）和视觉诱发电位（VEP）检查，并进行简易智力状态检查（MMSE）评分比较。结果：与NC组相比，AD组AEP的N1、P2，VEP的P1潜伏期延迟，AEP的P2、P2，VEP的P2、P3波幅降低；VD组VEP的P2潜伏期延迟，P2和P3波幅降低。AD组和VD组相比，AD组AEP的N1、P2潜伏期延迟于VD组。AD组VEP的P2波的潜伏期，VD组AEP的P3波幅及VEP的N1潜伏期改变与其MMSE评分有关联。结论：AD组和VD组的诱发电位有类似变化，两组的VEP和AEP变化与MMSE相关。     

慢性精神分裂症病人的症状和视觉诱发电位相关性分析

为了探讨精神分裂症的症状与视觉诱发电位的关系,本研究对32例慢性精神分例症病人进行了简明精神病量表、阴性症状量表、阳性症状量表的评定,以及视觉诱发电位检查。结果发现,右P_1波幅、N_2幅差与精神症状存在较明显的相关。右侧P_1波幅较好地反映了阴性症状;N_2幅差反映了整体精神症状,尤其是阳性症状。文中讨论了这一发现的应用价值和理论意义。     

基于颜色VEP的色觉缺陷检测系统的研究

本研究介绍了一种基于颜色视觉诱发电位（VEP）的色觉缺陷检测系统。现代电生理检测理论认为当视觉神经系统接收到颜色刺激时，将产生相应的脑皮层电位分布。通过适当的颜色刺激诱发，能够定量地测量色觉缺陷人群的缺陷种类及缺陷程度。该系统由颜色刺激发生器、测试电极、放大滤波电路、A／D转换电路、工作主机等部分组成。系统用等亮度反转点来表征色觉缺陷的种类及程度，实现了客观定量的色觉缺陷检测要求。     

Correspondence of Visual Evoked Potentials with FMRI Signals in Human Visual Cortex

Functional magnetic resonance imaging (FMRI) and event related potentials (ERPs) are tools that can be used to image brain activity with relatively good spatial and temporal resolution, respectively. Utilizing both of these methods is therefore desirable in neuroimaging studies to explore the spatio-temporal characteristics of brain function. While several studies have investigated the relationship between EEG and positive (+) BOLD (activation), little is known about the relationship between EEG signals and negative (−) BOLD (deactivation) responses. In this study, we used a visual stimuli designed to shift cortical activity from anterior to posterior regions of the visual cortex. Using EEG and FMRI, we investigated how shifts in +BOLD and −BOLD location were correlated to shifts in the N75 and P100 visual evoked potential (VEP) dipolar sources. The results show that the N75 dipole along with +BOLD, were indeed shifted from posterior to anterior regions of the visual cortex. The P100 VEP component, along with the −BOLD were not shifted to the same extent, indicating that N75 is better correlated to +BOLD than to −BOLD. These findings indicate how different components of the EEG signal are related to the positive and negative BOLD responses, which may aid in interpreting the relationship between visually evoked EEG and FMRI signals. An erratum to this article can be found at     

自制针电极在VEP、BAEP、SEP中的应用研究

本文介绍我院在多年使用外国产诱发电位仪器，因购买一次电极配套产品的价格昂贵，消耗量大，且使用效果差等因素，先是将一次表面电极改装成毫针电极，后又研制成完全自制的针电极，解决了原电极存在的问题和不足。     

Multifocal ERG and VEP responses and visual fields: comparing disease-related changes

Static visual perimetry and the multifocal technique both measure the local effects of diseases of the retina and optic tract. The purpose here is to relate the measures obtained from each technique and to describe this relationship in some diseases. It is important to measure both the implicit time and amplitude of the multifocal ERG (mERG) or multifocal VEP (mVEP) responses. Some diseases affect one measure of the responses but not the other. The comparison of either measure to local sensitivity changes measured with static perimetry (e.g. the Humphrey 24-2 and 30-2) presents a problem. Different stimulus displays are employed. Further, the multifocal responses are displayed with arbitrary spacing between the responses. One approach is to measure the amplitude and implicit time of the multifocal responses and display these values on the same coordinates as in the visual field plots. This allows a qualitative comparison of fields and multifocal responses on the same scale. A second approach involves modifying the Humphrey perimeter software so that the test spots are placed in the centers of the multifocal stimuli (e.g. the center of each hexagon of the mERG display). A third approach involves estimating the thresholds for the regions of the multifocal display by interpolating from values at the standard Humphrey locations. The second and third approaches produce a one-to-one mapping of the multifocal and field measures and allow a quantitative comparison between the two. The relationship between visual fields and multifocal responses, determined through one or more of these approaches, is different depending upon whether the disease primarily affects the outer retina (retinitis pigmentosa), ganglion cell (glaucoma), or optic nerve (ischemic optic neuropathy and optic neuritis). This revised version was published online in July 2006 with corrections to the Cover Date.     

Transient VEP and psychophysical chromatic contrast thresholds in children and adults

It has been found that humans are able to distinguish colours without luminance cues by about 2-4 months of age and that sensitivity to colour difference develops during childhood, reaching a peak around adolescence. This prolonged period of maturation is reflected by improvements in psychophysical threshold measures and by the VEP characteristics of morphology, latency and amplitude. An intra-individual comparison of VEP and psychophysical responses to isoluminant colour stimuli has not been made in children, however, and this was the aim of the present study. VEPs were recorded from 49 subjects, children (age range: 4.8-12.6 years) and adults (age range: 25.7-33.2 years). Psychophysical and VEP thresholds were both measured in 40 of those subjects. Nominally isoluminant chromatic (L-M) sinewave gratings were presented in onset-offset mode and identical stimuli were used for psychophysical and VEP recordings to allow comparison. In agreement with previous reports, morphology of the transient VEP in response to this stimulus differed considerably between children and adults. There was a significant difference between psychophysical and VEP thresholds in children, but not in adults. Our findings support and expand on previous work on maturation of the L-M chromatic pathway and indicate a larger discrepancy between VEP and psychophysical chromatic thresholds in children than in adults.     

大龄弱视儿童综合治疗的临床疗效观察

目的探讨大龄儿童弱视的治疗方法及疗效。方法对92例(111只眼)初诊的大龄弱视儿童(≥12岁)用阿托品散瞳验光配镜,并根据矫正视力,注视性质及眼位等情况,给予相应的方案治疗。结果 92例(111只眼)患儿治疗1年后,基本治愈35只眼、进步60只眼、无效16只眼。结论对大龄弱视儿童给予准确验光配镜,使用视觉诱发电位自律光盘,辅以遮盖、红光闪烁、精细目力训练、光刷视觉刺激等综合训练,仍可以取得较满意的疗效。     

Transcranial direct current stimulation and the visual cortex

Neuroplastic changes are defined as enduring changes in the organization of the central nervous system, such as the strength of connections, representational patterns, or neuronal properties, either morphological or functional. In recent years, new tools have emerged to induce and manipulate ongoing neuroplastic changes by external stimulation, either by modification of synchronized neuronal activity or modulation of the spontaneous firing rate. The first is performed by transcranial magnetic stimulation (TMS), the latter by direct current stimulation (tDCS). tDCS as a tool aims to induce prolonged neuronal excitability and activity alterations in the human brain via alterations of the neuronal membrane potential and results in prolonged synaptic efficacy changes. Apart from its impressive persistent excitability effects, it is a non-invasive method and can be applied painlessly. Most likely that up- or downregulation of different cortical areas by tDCS will open a new branch in the area of visual psychophysics.     

发作性偏头痛慢性转化机制的研究

目的从枕叶皮质兴奋性及脑组织代谢角度探求发作性偏头痛慢性转化机制。方法对发作性偏头痛患者、慢性偏头痛患者及对照组分别进行中脑导水管周围灰质(PAG)区1H-MRS检测及VEP检查,测定3组NAA/Cr及Cho/Cr及VEP异常率。结果发作性偏头痛组NAA/Cr较慢性偏头痛组及对照组高,有显著性差异(P0.05),后两组无明显差异(P0.05),3组受试者Cho/Cr及VEP异常率无明显差异(P0.05)。结论发作性偏头痛患者PAG区存在神经元代谢活化可能,提示发作性偏头痛慢性化过程中可能存在PAG区神经元代谢从活化至失代偿的演变过程。