特发性震颤病人经颅磁刺激对皮质静息期的影响

目的:研究特发性震颤(ET)病人经颅磁刺激(TMS)对皮质静息期(CSP)的影响,以探讨ET发生的机理。方法:对30名ET病人(ET组,平均年龄58.63±14.57岁)和24名健康人(正常对照组,平均年龄51.50±12.80岁)进行TMS测定皮质静息期(CSP),并进行比较。结果:ET组病人CSP为66.66~183.32 ms,平均126.23±31.37 ms;正常对照组为90.86~195.02 ms,平均131.52±27.44 ms。两组比较差异无统计学意义(P>0.05)。结论:TMS对ET病人和健康人的大脑运动皮质及其抑制性中间神经元静息期均无影响,推测这些部位对ET的发生无明显作用。     

脑裂畸形伴灰质异位患者体感皮质功能重组的脑磁图初探

脑裂畸形为神经元移行异常所致的先天性脑发育畸形,它以横跨大脑半球的脑裂为特征,临床较为少见,因为常伴发灰质异位,导致异位灰质周围的重要功能区如体感皮质及运动皮质定位困难,本文通过脑磁图结合磁共振形成磁源性影像对2例脑裂畸形伴灰质异位患者体感皮质的功能定位,观察体感皮质功能区位置变化。材料及方法:所用设备:使用Vectorview306通道全头型脑磁图设备(原美国4D-Neuroimag-ing公司生产),所有受试者均行MR检查,所用设备为美国GE公司生产的1·5T Singa HorizonMR成像系统,电刺激使用Zweifacn-Konstant-strom-stimulator系统。…     

正常人事件相关电位的检测与分析

本文报道ERP的检测方法和240例正常人的检测结果。探讨P_?波正常值范围及影响因索。结果表明.P_?波潜伏期为343.64±25.47ms,波幅P_?——N_?为7.15±3.90ηV,N_?——P_?为13.13±5.41μ。潜伏期、波幅与性别之间无显著性差异。但随着年龄的增加,潜伏期延长和波幅下降。     

脑卒中后体感皮质脑功能重组的脑磁图初探

脑卒中后约有3/4以上患者遗留不同程度的功能障碍,随着时间的推移,神经系统局灶性损伤后大部分患者可有不同程度的功能恢复[1]。本文对5例顶叶脑梗塞患者及1例顶叶脑出血患者恢复期进行了手区体感皮质功能区定位检查,发现体感皮质功能区位置与传统的解剖定位有一定差别,报告如下:材料及方法一、一般资料:右顶叶脑出血患者1例,男,45岁。单侧顶叶脑梗塞患者5例,其中男4例,女1例,患者年龄38-75岁,平均年龄54岁,病程1个月-20年,平均4年。二、检测设备:使用芬兰Neuromag公司生产的Vectorview306通道全头型脑磁图设备。所有受试者均行MRI检查,所…     

临床神经电生理学术语(17)

late response后反应指诱发电位中有两个以上潜伏期中的较长的一个反应,用以区别一个反应中较慢的部分即晚成分。在肌电图学中用来描述潜伏期比M波更长的诱发电位,也叫继发反应。在有关体感诱发反应方面,相对于由丘脑特异性投射系统参与的初级皮层波而言,经脑干网状结构非特异投射系统的后续波即称为后反应。latency潜伏期由刺激开始到刚发生偏转的时间,叫起始潜伏期(OL),由刺激开始到第一波顶点的时间叫峰潜伏期(PL),一连串波,波峰之间的时间差,叫峰间潜伏期(IPL),一般以ms计。latency of activation激活的潜伏期用电剌激使神经去极化…     

直立调节障碍患者交感神经皮肤反应研究

目的 :观察直立调节障碍患者的自主神经功能状况 ,评价交感神经皮肤反应 (SSR)在晕厥鉴别诊断中的应用价值。方法 :对 32例直立调节试验阳性的晕厥患者 (病例组 )进行电刺激SSR检测 ,并以 32例健康志愿者作对照。结果 :病例组SSR潜伏期延长 (1 5 4± 0 2 8s) ,波幅降低 (1 16± 0 33mV) ,与对照组SSR潜伏期 (1 36± 0 2 1s)和波幅 (1 87± 0 5 9mV)相比差异均有显著性意义 (P <0 0 1)。结论 :直立调节障碍患者存在交感神经功能障碍 ,在晕厥的鉴别诊断中 ,SSR是一种有实用价值的神经电生理方法。     

rTMS联合运动训练对运动皮质功能影响的研究

目的重复经颅磁刺激(rTMS)联合运动训练可有效提高肢体的运动能力。拟通过皮质静息期(CSP)记录的方法探讨rTMS联合运动训练对运动皮质功能的影响,进一步理解其提高运动能力的神经生理机制。方法募集了16例健康受试者,其中男性14例,女性2例;年龄23~31岁,平均年龄24.56岁。随机分为试验组和对照组,试验组进行为期14 d的rTMS联合运动训练,对照组仅进行14 d的运动训练。记录干预前后的CSP信号,并离线提取CSP中运动诱发电位(MEP)的幅值及潜伏期、CSP的持续时间。结果试验组左手MEP的幅值显著增加(z=3,P<0.05),潜伏期显著降低(z=25,P<0.05),CSP持续时间呈增加趋势,但是无统计学意义(z=6,P>0.05)。对照组左手MEP的幅值显著增加(z=4,P<0.05M),EP的潜伏期和CSP的持续时间均无显著变化(P>0.05)。两组受试者右手的MEP幅值、潜伏期和CSP持续时间的变化均无统计学意义(P>0.05)。结论rTMS联合运动训练同时调控了运动皮质兴奋和抑制性神经元的功能,它可能是rTMS联合运动训练提高肢体运动能力的重要原因。     

经颅磁刺激对部位相关癫癎患者运动皮质功能的评估

目的:采用经颅磁刺激技术(TMS)探讨症状性运动部位相关癫癎患者发作间期运动皮质的兴奋性.方法:对诊断明确的34例癫癎患者(分治疗组和未治疗组)及20例年龄、性别匹配的正常对照组进行单脉冲经颅磁刺激,刺激部位头颅相应的运动手区和颈7棘突外侧,并于对侧小指外展肌记录运动诱发电位(MEP),分析其阈强度(TI)、周围潜伏期(PL)及皮质潜伏期(CL)、中枢传导时间(CCT)和静息期(SP).结果:所有癫癎患者PL、CL及CCT均在正常范围内,但TI和SP明显低于正常对照组(P< 0.01).在癫癎患者中,未治疗组TI及SP明显低于治疗组(P< 0.01),致癎灶侧TI及SP低于非致癎灶侧(P< 0.05),但非致癎灶侧SP亦缩短.结论:单脉冲低频TMS能有效地反映中枢运动皮质的功能状态,用于症状性运动部位相关癫癎患者发作间期运动皮质兴奋性研究具有重要的实用价值.     

32例糖尿病患者交感神经皮肤反应的探讨

目的 :应用交感神经皮肤反应 (SSR)探讨与糖尿病 (DM)相关的植物神经功能状况。方法 :对 32例DM患者及正常组采用电刺激法进行SSR检测。结果 :正常组SSR波形可分为三种类型 :P型、N型、M型 ,其中M型易产生适应性 ,受皮温、刺激强度、深呼吸等影响。 32例DM患者SSR潜伏期异常 17例 ,异常率为 5 3%。DM组与正常组的SSR相比 ,潜伏期和波幅的差异均有非常显著性意义 (P <0 0 1)。病程≤ 5年DM组与正常组的SSR相比 ,潜伏期和波幅的差异均有显著性意义 (P <0 0 5 ) ;而与病程 >5年DM组相比 ,仅潜伏期差异显示显著性意义 (P <0 0 5 ) ,波幅虽有降低 ,但无统计学差异。结论 :SSR可以评价DM患者的植物神经功能状况 ,尤其是潜伏期更有价值 ,可以作为一项动态观察指标。     

足底血管的巨微解剖

在60侧(男女各半)成人足标本上对足底血管进行了观察和研究.其结果,足底内侧动脉始端外径,男性为1.68±0.22mm;女性为1.32±0.19mm,男女性间有显著差异.足底外侧动脉始端外径,男性为2.00±0.27mm;女性为1.73±0.27mm,男女性间有显著性差异.与此同时,对足底动脉浅弓、足底动脉深弓的组成、位置、分支进行了分析,初步确定了足底内侧动脉和足底外侧动脉,足底动脉浅弓和足底动脉深弓的体表投影.     

Morphometric study of glycine-immunoreactive neurons and terminals in the rat cuneate nucleus

The distribution of glycine-immunoreactive (glycine-IR) neurons and their associated axon terminals in the rat cuneate nucleus was studied using antiglycine postembedding immunoperoxidase labelling and immunogold staining, respectively. The immunoperoxidase-labelled glycine-IR neurons were widely distributed in the entire rostrocaudal extent of the nucleus. They made up 30.8% (9671/31368) of the neurons surveyed. Quantitative evaluation showed that the percentage of glycine-IR neurons in the caudal level was significantly higher than that in the middle and rostral levels. The glycine-IR neurons were small cells (mean area=198±1.9 μm², n=2862) with ovoid or spindle-shaped somata. Statistical analysis showed that the size of the glycine-IR neurons in the rostral level was significantly smaller than that in the middle and caudal levels. Immunogold labelled glycine-IR terminals which contained predominantly pleomorphic synaptic vesicles were mostly small (mean area=1.24±0.03 μm², n=286) and they constituted 24.7% (286/1158) of the total terminals surveyed. They formed axodendritic, axosomatic and axoaxonic synapses with unlabelled elements. It is suggested from this study that glycine is one of the major neurotransmitters involved in the depression of synaptic transmission in the cuneate nucleus.     

The anterior border zones of primary somatic sensory (S1) neocortex and their relation to cerebral convolutions, shown by micromapping of peripheral projections to the region of the fourth forepaw digit representation in raccoons

In raccoons the somatic sensory neocortex is greatly expanded, with separate gyral crowns devoted to and intervening sulci separating, sensory representations of separate body parts, most strikingly those of the volar surfaces of individual forepaw digits. Most of the cortex in this region is buried in widely ramifying sulcal walls, wherein sensory projections have not been studied. We have determined mechanosensory projections to the fourth digit representation region including all neighboring sulcal walls, using tungsten microelectrodes for 3-dimensional micromapping. We found no significant alteration in the location and pattern of projections when the following different anesthetics were used: dial-urethane, chloralose, or methoxyflurane with nitrous oxide. The precisely organized somatotopic representation of the distal volar surface of the fourth digit, on the causal aspect of its gyral crown, continues down the anterior bank of the triradiate sulcus. This meets, at the fundus, projections from the proximal volar surface of the digit which occupy the posterior sulcus wall; they in turn meet projections from the volar palm at the gyral crown. In the anterior part of the crown containing the representation of the distal volar digit, across the crown. In the anterior part of the crown containing the representation of the distal volar digit, across the crown of the gyral bridge intervening between the medial and lateral segments of the central sulcus, throughout the posterior walls of the central sulci, and in the walls of the interbrachial sulcus, we found a distinctive border-zone of projections from heterogeneous receptive fields. Within a roughly somatotopic basic pattern of organization we found intermingled projections from single and multiple claws and dorsal hairy surfaces of digits and proximal hand, along with additional projections from volar surfaces. These projections can be construed as forming something of a distorted mirror-image of the representation of the volar hand. Beyond this was a second zone of distinctive projections from afferents of the forelimb muscles, in the anterior walls of the central sulci. These projections are interrupted where the sulci are interrupted. The zone of muscle afferent projections corresponds to those seen between sensory and motor regions in other species; its strict association with sulcal folding here and in other species suggests a general relationship of these projections to central sulci. The zone of heterogeneous projections resembles similar zones seen at other levels of this system in raccoons, in the cortex of other species, and it may relate to some of the multiple representation reported in other species. It also may be related to the formation of sulci in this region and may be a specialized zone for cortico-cortical connections.     

Homotypical ipsilateral cortical projections between somatosensory areas I and II in the cat

In 11 cats, small quantities of horseradish peroxidase conjugated to wheat germ agglutinin were placed into cortical zones of somatosensory area I representing the distal digits (n = 3), distal toes (n = 2), toes and digits (n = 1), proximal forelimb (n = 1), proximal hindlimb (n = 1), trunk (n = 2), and the face and nose (n = 1). Reconstruction of the pattern of retrograde labeling in somatosensory area II revealed dense, heavily labeled patches of cells in regions that were precisely homotypical to the injection site as determined by electrophysiological recordings. This dense, homotypical patch of labeled cells was usually surrounded by a less densely populated fringe of labeled cells that bordered, but did not appear to enter, heterotypical zones. In two animals, however, some retrogradely labeled cells were found in the cortex representing somatotopic zones adjacent to the sites injected with horseradish peroxidase. These results indicated that somatosensory area II primarily sends homotypical projections to somatosensory area I. In a few cases, however, some retrogradely labeled cells may represent either homo-or heterotypical projections depending on how receptive field sizes and the areal extent of labeling in somatosensory areas I and II are interpreted.     

大鼠体感皮层后爪代表区的微电极测定

利用微电极测绘技术对Wistar大鼠大脑皮层体感一区进行电生理研究,测定了后爪代表区的面积、与相邻代表区的关系。证明后爪代表区内部存在分域关系,但由于后爪皮层代表区神经元的感受野较大,分域是粗略的。     

Thalamic and cortical high-frequency (600 Hz) somatosensory-evoked potential (SEP) components are modulated by slight arousal changes in awake subjects

Human somatosensory-evoked potentials (SEP) recorded at the scalp after conventional electrical median-nerve stimulation contain a low-amplitude (<500 nV), high-frequency (approximately 600 Hz) burst of repetitive wavelets, which are superimposed onto the primary cortical response N20. Previous electroencephalographic (EEG) studies have shown: (1) that these wavelets are generated near the hand area of the primary somatosensory cortex and in deep fibers of thalamocortical afferences; and (2) that only the 600-Hz burst, but not the N20 is decreased during sleep. Since the thalamus is involved in regulating both, selective attention and arousal, the present study aimed at characterizing the effects of focused attention and slight arousal changes on the 600-Hz oscillations. A dipole-source analysis of 64-channel SEP recordings after electric right-median-nerve stimulation allowed the comparison of brainstem, thalamic, and two cortical (one tangential, one radial) source activities in ten awake human subjects under two slightly different arousal states (eyes open vs. eyes closed), each tested for three conditions of focused attention (directed towards rare acoustic and right- or left-hand somatosensory target stimuli). While the N20 was not modified at all, the source strength of the high-frequency wavelet burst was significantly increased for eyes opened versus eyes closed, at the thalamic source site as well as for the tangentially oriented cortical source. In contrast, there were no significant differences between conditions with different attentional targets. This evidence for modulatory effects of increased arousal (eyes open) on both thalamic and cortically generated high-frequency SEP activity fits the hypothesis that the 600-Hz SEP burst at least partially represents an arousal-dependent signal generated at the thalamic level and transmitted to the primary somatosensory cortex.     

大鼠脑缺血不同时期躯体感觉诱发电位的研究

脑电信号（EEG）具有较高的时间分辨率、可观测脑内活动的动态变化、完全无损检测等优点,常用于对神经系统疾病的诊断,本研究探讨脑缺血后躯体感觉诱发电位（SEP）变化及大脑皮层的功能恢复。利用线栓法建模成功的25只SD雄性大鼠分为5组,分别为正常对照组和左侧中动脉缺血术后4、24、 48 h和1周4个实验组。采用SEP记录法,在术后不同时间段电刺激大鼠的右前爪正中神经支配区,记录对照组和实验组左侧皮层脑电信号,提取SEP,并对安静状态下的脑电进行频谱分析,定量评价左侧中动脉缺血后初级体感皮层SEP及功率谱变化过程。实验结果显示,术后4 h,SD大鼠左侧大脑皮层测得的SEP潜伏期较正常状态显著增大（（16.0±1.1）ms vs（33.7±1.3）ms,P<0.01）,波幅变小（（197.2±13.0）μV vs（25.1±2.0）μV,P<0.01）,θ波、α波、β波、γ波的能量明显变小。θ波：（139 367.86±178.66）μV^2vs（2.22±0.40）μV²,P <0.01;α波:（5389.33±25.55）μV² vs（0.23±0.01）μV²,P<0.01;β波：（7911±416）μV² vs（0.01±0.01）μV²,p<0.01; γ波：（0.30±0.12）μV² vs（0.00±0.00）μV²,P<0.01。随着术后时间的延长,上述特征与对照组的差距逐渐缩小,但还不能达到正常状态的水平。研究提示,SEP可在一定程度上反映脑缺血大鼠大脑皮层功能的变化。     

视、听、体感目标探测的EEG频谱和空间特异性分析

利用行为学和EEG频谱能量分析方法,考察大脑对视、听和体感单通道靶刺激探测的频段和空间半球分布.采集14位健康受试者的64导联脑电数据,实验材料分为视觉、听觉和体感觉的靶刺激和非靶刺激.分析了3个感觉通道下所有受试者靶刺激EEG Power显著强于非靶刺激的频谱和脑区分布,还比较了3个感觉通道靶刺激的行为学数据.结果表明,体感觉靶刺激探测的难度显著大于听觉和视觉靶刺激探测.delta和theta频段在三感觉通道靶刺激探测过程中都发挥主要作用,印证ERPs成份中的P300在三感觉通道靶刺激探测过程中发挥主要作用.大脑对近点靶刺激的探测具有明显的左半球优势.三感觉通道靶刺激探测的行为学结果(错误率)与EEGPower结果(显著性差异电极统计)趋于一致,表明EEG Power分析可作为视、听、体三通道认知任务难度分类的潜在电生理学参数.     

兔水中毒时体感诱发电位

应用水负荷附加抗利尿激素,复制水中毒模型。当水负荷增加兔体重10%后,体感诱发电位(SEP)成份P7、N9、P12和N15峰值潜伏期随体重增加而逐渐延长。体重增加10%及15%时,P12和N15成份振幅均增大,但当增加体重15%以上时,两成份振幅减小或消失。水负荷后SEP峰间潜伏期的延长以P12—N15最显著。各种程度水负荷时,P7和N9的振幅均无显著变化。结果说明,水负荷增加体重10%后,可使神经元的传导发生延缓及皮层神经元兴奋性改变;不同程度的水负荷对神经元兴奋性的影响并不相同,此外水负荷对大脑皮层功能的影响较低位脑干严重。