癫癎病人的剥夺睡眠诱发脑电图分析

目的:探讨剥夺睡眠诱发方法是否可提高癫癎病人脑电图癫癎样波的阳性率。方法:对临床拟诊为癫癎,而常规脑电图描记正常的100例研究组行剥夺睡眠诱发实验,并选择46例对照组。结果:研究组剥夺睡眠诱发脑电图呈现爆发性癫癎样波者42例(42%),对照组脑电图无1例呈爆发波,两组相比有统计学意义(P<0.001)。结论:脑电图有轻度改变者,剥夺睡眠诱发实验可提高癫癎病人脑电图癫癎样波的阳性率。     

剥夺睡眠──睡眠诱发脑电图在癫癎诊断中的应用探讨

长期以来,神经病学和临床神经电生理学家一再指出,对有明确的或可能的发作性疾病患者,需要进行睡眠描记。出现棘波或尖波放电将可证实发作性疾患的存在,而这些放电常常（约８０％的机会）只有在睡眠描记时才能发现。因此,对一个拟诊癫　的病人,如果清醒脑电图没有发现　样放电,应作睡眠描记。一般情况下,应着重描记睡眠第一阶段（思睡期）和第二阶段（浅睡期）,以查明有无局灶性发放。在实际工作中,要想获得满意的脑电图资料,剥夺睡眠不失为一种简便、有效的方法。１ 资料与方法 临床资料：４５例患者均有１次以上发作性症状出现…     

剥夺睡眠脑电图监测对癫癎诊断的意义

近年来 ,长程脑电图监测技术的发展 ,对提高癫脑电图的异常率及对癫分型有很大的帮助。我院从 1998年 8月至 2 0 0 2年 8月共对 4 7例临床有癫样发作的患儿进行了清醒时的脑电图监测与剥夺睡眠后睡眠时的脑电图的监测。现将结果报告如下。1　临床资料本组 4 7例患儿中 ,男 30例 ,女 17例。发病年龄 3～ 14岁 ,其中 3～ 7岁 10例 ,7～ 10岁 2 8例 ,10～ 14岁 9例。临床表现主要为全身性发作的 2 4例 ,单纯部分性发作的 10例 ,复杂部分性发作的 13例。其中白天发作 9例 ,入睡后发作 38例。2　脑电图资料采用江苏伟思公司生产的同步录像…     

脑磁图在癫(癎)诊治中的应用

脑磁图(magnetoencephalography,MEG)早在35年以前就已进入神经科学研究领域,它是通过一种敏感性极高的检测仪器——超导量子统计推断仪(SOUID)检测脑部微弱磁场的技术。但直到今天,随着科技的发展,建立了全脑MEG系统以及便于操作者使用的技术分析方法,才使MEG的临床应用得以实现。尽管脑电图(electroencephalography, EEG)和MEG都是基于神经电生理的检查技术,即     

脑磁图和脑电图在癫癎中的应用

脑磁图（MEG）和脑电图（EEG）可以分析1ms甚至更短时间的神经生理学数据，这种特殊性是其它神经影像技术所不能替代的。虽然EEG和MEG都来自相同的神经生理学过程，但是它们却存在着很大的差异，表现在：①磁场较少受到颅骨和头皮的衰减，理论上MEG具有更好的空间分辨率；②电场与磁场导向互相垂直，通常高敏感性的方向彼此垂直交叉。     

癫癎儿童剥夺睡眠诱发试验的脑电图分析

目的:分析脑电图剥夺睡眠诱发试验在癫诊断上的应用价值。方法:记录58例癫儿童剥夺睡眠后的脑电图变化。结果:与本组常规脑电图比较,样放电检出率提高至79·31%。结论:剥夺睡眠诱发试验能明显提高癫儿童脑电图阳性率。     

睡眠诱发加蝶骨电极脑电图在癫癎诊断中的应用

常规脑电图检查作为癫癎诊断的主要检查手段仍被广泛应用,但受检查时间短、缺乏睡眠期脑波记录等缺陷的限制,异常检出率不高.     

蝶骨电极加剥夺睡眠脑电图对癫癎的诊断

目的：探讨蝶骨电极加剥夺睡眠脑电图（ＥＥＧ） 对癫癎诊断的价值。方法：对１１０ 例癫癎患者进行常规电极和蝶骨电极描记,如无癎样放电,再作蝶骨电极加过度换气和蝶骨电极加剥夺睡眠,并与常规电极作比较。结果：常规电极癎样放电检出率为３８－１ ％ ,单纯蝶骨电极,蝶骨电极加过度换气和蝶骨电极加剥夺睡眠癎样放电检出率比常规电极分别提高１１ ％ （χ２ ＝ ２ ．６ ,Ｐ＞ ０－０５） ,１９－２ ％ （χ２ ＝８ ．１１ ,Ｐ＜ ０－０１） 和３４－２ ％ （χ２ ＝ １７ ．２２ ,Ｐ＜ ０－０１） 。结论：在上述几种方法中,以蝶骨电极加剥夺睡眠癎样放电检出率最高,故对癫癎诊断的价值最大。     

癫癎患者睡眠诱发检测的临床意义

目的：分析癫癎病人加做睡眠诱发试验的临床意义。方法：在常规脑电图检查基础上加做睡眠诱发试验。结果：在清醒状态下未记录到异常的患者,约40％可以在睡眠中记录到癫癎样放电。结论：脑电图常规检查合并睡眠诱发试验既安全无痛苦,又经济可靠,可在基层医院常规作为癫癎病的辅助诊断。     

Localization of fast MEG waves in patients with brain tumors and epilepsy

It was investigated if single dipole analysis of spontaneous fast waves (>8 Hz) can be used to determine the location of the epileptic focus. Automatic dipole analysis was applied to MEG data of 25 patients with intracranial tumors and epilepsy. The frequency range of 8-50 Hz was divided into standard EEG bands. MEG results were overlaid on the MRI scans of the patients. Dipoles describing fast wave fields were located in the parietal/occipital cortex, and not at tumor border zones. In the cases that the dipoles were lateralized there was no clear preference to be located ipsi or contralateral to the tumor. However the generators of epileptic activity in these patients are thought to be located in the border areas of the tumors. Therefore it seems unlikely that the dipole locations describing fast waves are related to the epileptic zones in patients with brain tumors and epilepsy. A remarkable finding is that lateralized dipoles tend to be located in the right hemisphere and not in the left hemisphere. This appears to reflect an asymmetry of possibly normal background activity.     

癫(癎)合并睡眠呼吸暂停综合征的研究

目的:探讨癫癎与睡眠呼吸暂停综合征(SAS)的相互关系,观察SAS的治疗对癫癎发作的影响。方法:从39例癫癎患者中筛选出可能合并SAS的病例进行多道睡眠图(PSG)监测,对确诊为SAS的中-重度患者行经鼻持续气道正压通气治疗(nCPAP)。结果:39例癫癎患者中有18例(46％)合并有SAS,且合并SAS的患者癫癎发作频率较高,平均为0．82次／月,与单纯癫癎患者的平均0．28次／月相比,明显升高(P<0．01)。经nCPAP治疗,癫癎发作频率减少至平均0．35次／月,与治疗前相比差异有显著意义(P<0．01)。结论:成人癫癎患者合并SAS发生率较高,SAS可加重癫癎的发作,治疗并存的SAS可提高对癫癎发作的控制力度,改善癫癎患者的生活质量。     

MEG inversion using spherical head model combined with brain-shaped head model

INTRODUCTION　　 Neural currentsources in the human brain produce external magnetic fieldsthatcan be measured noninvasively by using superconducting quantum interferencedevices(SQUID s) .This technique is called Magnetoencephalography(MEG)〔1〕that is becoming a promising technique for brain function research and diagnosis ofsome brain disease〔2〕.In many cases the neuromagnetic sources can be modeled aseveral current dipoles that are appropriate for interpreting postsynaptic potentia…     

468例癫癎患者睡眠期癎样放电与睡眠结构变化分析

目的：观察癫 患者的睡眠时相与 样放电的关系,并初步探讨癫 异常脑波活动对睡眠的影响。方法：对４６８例癫　患者进行２４小时动态脑电图（ＡＥＥＧ）监测,观察发作间期清醒与睡眠脑电图　样放电的发作频率,分析５８例癫　患者及对照组睡眠脑电图中睡眠时程、觉醒次数、睡眠纺锤波的变化。结果：４６８例患者中出现　样放电３６２例,睡眠期　样放电检出率８８％,觉醒期检出率５８％。样放电主要出现于ＮＲＥＭ睡眠Ⅰ－Ⅱ期。与对照组比较,癫　组ＮＲＥＭ　Ⅰ－Ⅱ睡眠期延长,ＮＲＥＭ Ⅲ－Ⅳ期缩短;觉醒次数增加,觉醒次数与　样放电频率呈正相关;并有睡眠纺锤波减少及不对称。结论：癫　患者的　样放电主要出现于ＮＲＥＭ睡眠Ⅰ－Ⅱ期,癫　活动对睡眠有一定影响,癫　患者睡眠质量下降。     

脑磁图在耐药性癫(癎)术前定位中的价值及影响因素探讨

目的:评价脑磁图(MEG)在耐药性癫癎术前定位中的价值并探讨影响其定位的因素。方法:在47例术前均行MEG,VEEG,MRI检查的耐药性癫癎病例中,以术中皮层脑电图(ECoG)为金标准,比较VEEG和MEG定位准确性,并作影响MEG和VEEG定位的logistic多因素分析。结果:47例颞叶癫癎中,MEG与ECoG完全吻合32例(68％),部分吻合8例(17％);VEEG与ECoG完全吻合18例(38％),部分吻合23例(49％)。MEG与ECoG完全吻合病例明显多于MEG与VEEG吻合例(P <0．05)。MEG定位的多因素分析显示发作频率对MEG定位有影响(P<0．05)。结论:MEG的应用有助于致癎灶的准确定位和手术方式的选择,在难治性颞叶癫癎的术前定位中有重要的临床应用价值。     

Age Distribution of MEG Spontaneous Theta Activity in Healthy Subjects

No HeadingSummary: This study investigates the possible relevance of distribution and age variation of spontaneous theta activity (4–8 Hz) in normal subjects using magnetoencephalography (MEG) recordings. Spontaneous theta was recorded with a 151-channel MEG in healthy subjects; moreover, in a group of 10 subjects, simultaneous MEG-EEG was recorded in order to compare the two methods. Theta was divided in two sub-bands: TA (4–6 Hz) and TB (6–8 Hz). The pre-processed data were transformed into the frequency domain by Fast Fourier Transform (FFT)-based software by subdividing the data in epochs of 5 sec, on which FFT amplitudes are computed. Moreover, on all trials a simple model of a single electric current embedded in a spherically symmetric conductor was fitted automatically to the magnetic fields and projected onto an averaged MRI. The results obtained show that FFT-based theta power spectrum was distributed in adults with the highest power over the posterior parietal and occipital areas with TB dominance. The dipole analysis resulted in a mid-sagittal distribution, though the youngest group displayed theta dipoles fitting more posteriorly respect to the adults and the elderly. These results suggest that spontaneous theta activity is a diffuse and pervasive rhythm which shows some different topographical distribution among the age groups. Whether the prevalent posterior distribution of theta is the expression of distinct networks or the outcome of complex dynamics are questions of possible relevance in the organization of higher order processes.     

Dissociation of summation and peak latencies in visual processing: An MEG study on stimulus eccentricity

Research on the temporal characteristics of visual processing, as measured with critical flicker fusion or the latency of visual evoked potential (VEP), shows controversial results if different eccentricities of visual stimuli are compared. To clarify this question, a direct measure of cortical activity with magnetoencephalography (MEG) was applied to examine the neuronal summation latency and peak latency for both near and far peripheral stimuli. Consistent with cortical magnification, the peak amplitude for less eccentric stimuli was larger than that for more eccentric stimuli. More importantly, the current data also demonstrated longer cortical summation latency and peak latency for more eccentric visual stimuli, but only the summation latency difference between near and far stimuli correlated with the peak amplitude difference between near and far stimuli. These results suggest dissociable mechanisms of summation latency and peak latency with respect to their contributions to the stimulus eccentricity effect, and provide potential explanations for controversial results in previous studies.     

Source models of sleep spindles using MEG and EEG measurements

Summary MEG measurements can detect brain sources that are difficult to detect with EEG measurements. The purpose of this study was to investigate models of sleep spindles using both MEG and EEG activity that had been recorded simultaneously. The components of magnetic fields perpendicular to the surface of the head were measured using a DC-SQUID with a first-derivative gradiometer. We propose three models for sleep spindles. In the first model, the source slides into the superficial region of the head so as to be perpendicular to it's surface, and with this model, the power spectrum of the MEG is decreased. In the second model, the source slides into the deeper structures, so that it is perpendicular to the surface. Here, the power spectra of both the MEG and the EEG are decreased. The third model has the source perpendicular to the surface, leaning and sliding into the deeper structures. Here, the power spectrum of the EEG is decreased but that of the MEG is not.     

Transient Global Amnesia (TGA) in an MEG Study

A patient who had experienced an attack of transient global amnesia (TGA) was examined using neurophysiological methods. Magnetoencephalography (MEG) was performed and the Wechsler Memory Scale-Revised (WMS-R) test was administered at 5 days and at more than a month after the TGA episode. MEG data on neuronal activity obtained while the patient was undertaking a working memory task and during rest were analyzed using the wavelet-crosscorrelation method, which reveals time-lag and information flow between related sites in the brain. The WMS-R memory scores showed dramatic improvement when the test was administered a month following the attack, although no significant changes were observed in EEG, MRI and SPECT data. The MEG study revealed that under a working memory load how the neuron works functionally and the information propagates assembly within the right hemisphere, and that these brain functions were not performed adequately shortly after the TGA attack.