脑磁图在癫痫致痫灶及灶周脑功能区定位中的作用

目的：脑磁图是通过测定神经元兴奋产生的电流所伴随的磁场变化来确定异常放电的部位，了解其在癫痫致痫灶和痫灶周围脑功能区定位中的作用。资料来源：应用计算机检索Medline1998-07／2004-11与脑磁图和癫痫相关文章，检索词“Epilepsy，Magnetoencephalography，localization”，并限定文章语言种类为English。计算机检索VIP和CJFD1999／2004与脑磁图和癫痫相关的中文文章，检索词“癫痫，脑磁图，定位”。资料选择：对资料进行初审，纳入标准；①回顾性研究，无论是否设有对照组。②研究为随机抽样。开始查找全文，未排除是否为盲法。资料提炼：共收集到91篇相关文献（英文84篇，中文7篇）。54篇符合纳入标准。排除的37篇文章中34篇系重复研究，3篇为Meta分析。资料综合：54篇文章中14篇从偶极子定位方面阐述，13篇涉及脑磁图对癫痫患者手术前后评估，16篇与其他定位技术比较证明脑磁图的作用。11篇采取个案报道的形式证实脑磁图的定位价值。从中选取13篇有代表性的文献进行综述，认为作为无创性检测技术，脑磁图可检测到直径〈3．0mm的癫痫病理灶，分辨时相高达1．0ms，可以发现癫痫原发病灶与对侧对称位置出现的类似信号，即“镜像灶”，还能分辨发作间期一侧大脑半球的多个癫痫灶。脑磁图可用于癫痫发作期和发作间期致痫源的定位，还可对痫灶周围脑功能区进行定位，与脑电图比较，其使用更方便，更敏感。结论：脑磁图对各类癫痫的诊断，致痫灶、灶周脑功能区的定位，癫痫镜像灶的辨别具有明显的优势和广泛的应用前景。     

视频脑电图结合MRI检查对药物难治性癫痫诊断的价值

目的探讨用视频脑电图和MRI诊断药物难治性癫痫的临床价值。方法收集2006年12月一2010年5月间经手术和病理证实的药物难治性癫痫患者38例。其中,海马硬化25例,颞叶萎缩伴脑发育不良2例,脑灰质移位及巨脑回4例,血管畸形3例,胶质瘤2例,脑内囊肿1例,外伤性癫痫1例。用视频脑电图监测癫痫发作期及发作间期痫样放电的来源部位及脑电活动特点,用MRI扫描显示痫灶区的表现特征,并与手术、病理改变对照,进行回顾性分析。结果视频脑电图对癫痫发作期的致痫灶来源定位准确率为100％（38／38）,发作间期定位准确率为53％（20／38）。MRI对发作间期的致痫灶及相关病变定位诊断准确率为89％（34／38）,病变定性准确率为79％（30／38）。结论视频脑电图和MRI检查有机结合,对药物难治性癫痫,能更有效检出致痫灶的部位及性质,为药物难治性癫痫患者的手术治疗,提供重要信息。     

脑磁图在癫痫致痫灶及灶周脑功能区定位中的作用

目的:脑磁图是通过测定神经元兴奋产生的电流所伴随的磁场变化来确定异常放电的部位,了解其在癫痫致痫灶和痫灶周围脑功能区定位中的作用。资料来源:应用计算机检索Medline1998-07/2004-11与脑磁图和癫痫相关文章,检索词“Epilepsy,Magnetoencephalography,localization”,并限定文章语言种类为English。计算机检索VIP和CJFD1999/2004与脑磁图和癫痫相关的中文文章,检索词“癫痫,脑磁图,定位”。资料选择:对资料进行初审,纳入标准:①回顾性研究,无论是否设有对照组。②研究为随机抽样。开始查找全文,未排除是否为盲法。资料提炼:共收集到91篇相关文献(英文84篇,中文7篇)。54篇符合纳入标准。排除的37篇文章中34篇系重复研究,3篇为Meta分析。资料综合:54篇文章中14篇从偶极子定位方面阐述,13篇涉及脑磁图对癫痫患者手术前后评估,16篇与其他定位技术比较证明脑磁图的作用,11篇采取个案报道的形式证实脑磁图的定位价值。从中选取13篇有代表性的文献进行综述,认为作为无创性检测技术,脑磁图可检测到直径<3.0mm的癫痫病理灶,分辨时相高达1.0ms,可以发现癫痫原发病灶与对侧对称位置出现的类似信号,即“镜像灶”,还能分辨发作间期一侧大脑半球的多个癫痫灶。脑磁图可用于癫痫发作期和发作间期致痫源的定位,还可对痫灶周围脑功能区进行定位,与脑电图比较,其使用更方便,更敏感。结论:脑磁图对各类癫痫的诊断,致痫灶、灶周脑功能区的定位,癫痫镜像灶的辨别具有明显的优势和广泛的应用前景。     

应用脑磁图合成孔径磁场测定技术进行运动功能区和致痫灶定位的研究

目的利用脑磁图（MEG）的合成孔径磁场测定（SAM）技术对中央沟附近病变进行运动功能区和致痫灶定位研究,评估SAM技术在脑功能区病变和癫痫手术中的应用价值,明确MEG的空间定位优势。方法对12例中央沟附近病变（其中6例合并癫痫）的患者术前进行Karnofsky生活状态评分（KPS）,采用SAM技术确定颅内病变、运动功能区和致痫灶的位置关系,指导手术方案的制定。术中通过诱发电位监测和皮质及深部脑电监测,术后通过随访复测KPS评分和癫痫发作情况,明确SAM技术定位的准确性。结果本研究的12例患者运动诱发磁源成像均定位于中央前回附近,6例合并癫痫的患者致痫灶定位结果均与术中脑电图监测一致,所有患者根据SAM定位结果确定手术方案和指导手术进行。8例患者KPS评分改善,运动功能有所恢复;所有患者均没有额外的功能损害发生。6例癫痫患者中有5例癫痫控制良好,1例患者癫痫控制不佳。结论SAM技术可以对功能区和致痫灶进行精确定位,同时可以明确颅内病灶与功能区和致痫灶的位置关系,指导手术治疗方案,控制癫痫,减少术后残疾的发生率。     

磁源性影像对癫痫灶定位的临床应用 ——与VEEG、ECoG比较

目的:探讨磁源性影像在癫痫灶定位中的应用价值。方法:20例难治性癫痫患者,男15例,女5例,手术前均行视频脑电图(Video-Electroencephalography,VEEG)、MRI及脑磁图(Magnetoencephalography,MEG)检查。将MEG所得的电生理资料与MRI所获得的解剖结构资料叠加,形成磁源性影像(magnetic source imaging,MSI)。所有患者手术均在MSI指导下进行术中皮层脑电图(Electrocorticography,ECoG)监测。结果:20例患者MSI与VEEG符合率为50%,与ECoG符合率为70%,术后(3~20月)随访16例患者疗效满意。结论:MSI是难治性癫痫患者手术前无创伤性癫痫灶精确定位方法。     

磁源性影像在海马硬化致癫灶定位中的应用

目的：探讨磁源性影像对由海马硬化引起的颞叶癫痫术前致癫灶定位价值。方法：对16例海马硬化的病例术前实行脑磁图检查,并应用磁源性影像技术对致癫灶进行定位。结果：术后随访,按照南京军区总医院的评估标准：满意14例（87.5%）;显著改善1例（6.25%）;疗效差1例（6.25%）;总有效率93%。磁源性影像定位与视频脑电图的定位完全符合率为62.5%。结论：磁源性影像可以明确海马硬化患者癫痫源异常放电位置,可以用于术前致癫灶的定位。     

头颅磁共振成像、视频脑电图、正电子发射 断层成像术对癫痫致痫灶的定位评估

目的:探讨头颅磁共振成像(MRI)、视频脑电图(VEEG)、正电子发射断层成像术(PET)对癫痫致痫灶的定位评估。方法:接受手术治疗切除致痫灶的癫痫患者73例纳入研究,所有患者术前均行头颅VEEG、MRI、PET检查,比较3种检查方法术前定位与术中定位的准确性;同时比较两两之间的检出率。结果:本组MRI阴性24例,MRI阳性49例(67%)。VEEG、MRI和PET术前定位与术中定位比较阳性率差异有统计学意义(P0.05),PET阳性率最高。PET与VEEG的诊断一致性高于MRI与VEEG的诊断一致性(P0.05)。结论:PET对癫痫病灶定位的敏感性高于MRI及VEEG,对于MRI阴性的患者更需要完善PET和VEEG检查。     

磁源性影像对脑海绵状血管瘤伴发癫痫的术前评价

目的：探讨磁源性影像（MSI）对脑海绵状血管瘤（CA）伴发癫痫患者的癫痫灶定位价值,为癫痫外科手术提供依据。方法：对13例脑CA伴发癫痫的患者进行了MRI和MSI检查。观察CA与MSI所确定的癫痫灶之间的位置关系。所有13例患者均经手术治疗。结果：13例患者中,11例CA位置与MSI所确定的癫痫灶位置距离<2cm,2例>2cm。按照Engel分级标准,所有患者均为1级,术后（6～53个月）随访12例患者术后癫痫未发作,1例癫痫发作1次。结论：MSI能明确CA与癫痫灶之间的位置关系,对术前制定手术计划有重要意义。     

PET脑显像在癫痫患者致痫灶定位中的价值

目的探讨18F-脱氧葡萄糖(18F-FDG)正电子发射计算机断层(PET)脑显像在各类癫痫患者致痫灶定位中的价值.方法对65例癫痫患者于发作间期行 18F-FDG PET脑显像,将其定位结果与头皮脑电图(EEG)、CT或MRI结果进行比较,并对其中14例定位后接受手术或放射治疗患者的预后情况进行分析.结果 65例患者中,56例(86%)患者发作间期PET图像上可见皮层局限性低代谢灶,4例(6%)可见皮层局限性高代谢灶,其余5例(8%)未见异常代谢灶.在PET图像呈典型低代谢表现的56例患者中,PET定位结果与EEG定侧(判定左右半球)或定位(判定具体脑叶)结果相符者40例(71%),EEG呈弥漫性异常者(无法定位)10例(18%),EEG检查未见异常者1例(2%),另5例(9%)PET定位结果与EEG定位结果不符.该56例患者中,44例(79%)CT或MRI检查阴性,12例(21%)CT或MRI检查阳性,后者中有11例PET定位结果与CT或MRI定位结果相符.明确致痫灶后接受手术或放射治疗的14例患者,平均随访2年,9例(64%)术后未再有癫痫发作或有不同程度的缓解.结论对于头皮EEG无法准确定位和CT、MRI检查阴性的癫痫患者,18F-FDG PET脑显像可替代部分侵入性EEG检查用于致痫灶定位,而不同的PET定位图形对患者手术方案的选择也有重要指导意义.     

PET和脑磁图在术前评估MRI阴性癫痫中的作用

目的分析PET和脑磁图在术前评估MRI阴性癫痫中的作用。方法选取12例难治性癫痫(TLE)患者为研究对象,比较患者术前PET和脑磁图与手术结果。同时选取15名正常健康志愿者,通过病史、一般体格检查和常规实验室检测进行筛选。结果 1所有纳入本研究患者大脑MRI被视为没有MRI阴性癫痫的诊断价值。12例患者完全是正常的(1例在前叶显示极微小的异常)。218F-FCWAY的血浆游离分数(f1)在TLE患者高于健康对照(0.13±0.04 vs.0.09±0.07,P0.10)。3在局灶化MEG刺激区组8例,所有8例有局灶化癫痫发作。单侧性的MEG刺激区组7例,3例局灶化癫痫发作。非单侧MEG刺激区组2例没有局灶化癫痫发作。结论术前定位MRI阴性癫痫,PET/MEG结果一致时,手术结果判定比较准确。     

Epilepsy surgery, resection volume and MSI localization in lesional frontal lobe epilepsy

To verify whether interictal noninvasive information detected by magnetoencephalography (MEG) recordings can contribute to localize focal epileptic activity relevant for seizure generation in lesional frontal lobe epilepsy, magnetic source imaging (MSI) localizations of epileptic discharges were compared to the extent of neurosurgical resection and postoperative outcome. Preoperative MEG spike localizations were displayed in postoperative magnetic resonance imaging (MRI) scans to check whether dipole sites were located within the resection cavity. Moreover, MEG localizations were compared with results of prolonged video-EEG monitoring and, in three cases, with invasive EEG recordings. Our results in five cases with lesional frontal lobe epilepsy showed that good surgical outcome could be achieved in those patients where the majority of MEG spike localizations were located within the resected brain volume.     

脑磁图在癫(癎)诊断和治疗中的应用

目的应用脑磁图(MEG)技术对致灶进行定位,比较其与头皮脑电图(EEG)在神经影像学方法的应用价值,探讨MEG技术对癫灶定位的应用前景。方法对113例癫患者进行手术治疗,术前均通过临床症候学、头皮EEG、MRI、MEG检查,进行MEG与其他检查方法和临床症候学在定侧、定叶诊断的对比研究。手术在皮层EEG及脑深部EEG监测下进行,手术治疗结果以Engel疗效分级评价。所有手术标本常规行光镜检查。结果113例患者中MEG定位局限于单个叶的为91例,头皮EEG仅为30例。术前致灶定位依据多种检查结果和临床症候学综合定位。MEG与MRI、临床症候学在定侧诊断准确性方面比较差异有显著性。MEG与MRI在定叶诊断准确性方面的比较差异有显著性。36例术前头皮EEG表现为双侧或全导癫波的癫患者,其中有34例MEG表现为单侧癫波,具有定侧诊断的意义。结论头皮EEG、MRI、正电子发射计算机断层扫描(PET)、临床症候学均不足以做出独立精确的致灶定位诊断,综合比较MEG比上述方法定侧和定叶的准确性高。MEG空间分辨率、时间分辨率高,有助于区分致灶和镜灶。     

联合磁源性影像和磁共振波谱技术评估颞叶癫痫的价值

目的：探讨磁源性成像（MSI）和磁共振波谱（^1H—MRS）技术结合在颞叶癫痫诊断定位中的价值。方法：设健康对照者10例，特发颞叶癫痫患者8例，应用MEG定位痫性病灶，选取MEG异常区域、对侧相应区域和双颞叶内侧区域测量NAA／Cho值，并观察是否存在海马硬化。结果：8例患者MEG检查结果均异常，6例MEG异常相应区域MRS检查NAA／Cho值减少，符合率为62．5％；MRI显示海马硬化2例，MRI正常6例，颞叶内侧MRS扫描未见明显改变。结论：联合MSI和MRS技术可进一步提高颞叶癫痫致痫灶的定位准确性。     

Spatial intralobar correlation of spike and slow wave activity localisations in focal epilepsies: a MEG analysis

12 patients with focal epilepsy were examined by magnetoencephalography (MEG). Source localisations of interictal epileptiform activity (spikes) yielded clear results. Slow wave dipole density in the frequency range from 2 to 6 Hz, using time selections from an automatic principal component analysis (PCA), was calculated. Results of spike and slow wave dipole density localisations were superimposed on MR-images of each patient. Slow wave dipole densities were increased close to spike localisations. Distances between spike center of mass and slow wave maxima were calculated, average mean distance was 2.0 cm. Independant of the localisation in either TLE or ETLE a concordance of slow wave and spike localisations were found. Slow wave localisations were found in patients with lesions in MRI and patients with no abnormalities on the MRI. In comparison to healthy subjects, slow wave dipole density in patients with epilepsy was clearly increased. The localisation of slow wave dipole density yielded additional important information and may contribute to defining the irritative zone.     

Combined MEG/EEG analysis of the interictal spike complex in mesial temporal lobe epilepsy

We studied the functional organization of the interictal spike complex in 30 patients with mesial temporal lobe epilepsy (MTLE) using combined magnetoencephalography (MEG)/electroencephalography (EEG) recordings. Spikes could be recorded in 14 patients (47%) during the 2- to 3-h MEG/EEG recording session. The MEG and EEG spikes were subjected to separate dipole analyses; the MEG spike dipole localizations were superimposed on MRI scans. All spike dipoles could be localized to the temporal lobe with a clear preponderance in the medial region. Based on dipole orientations in MEG, patients could be classified into two groups: patients with anterior medial vertical (AMV) dipoles, suggesting epileptic activity in the mediobasal temporal lobe and patients with anterior medial horizontal (AMH) dipoles, indicating involvement of the temporal pole and the anterior parts of the lateral temporal lobe. Whereas patients with AMV dipoles had strictly unitemporal interictal and ictal EEG changes during prolonged video-EEG monitoring, 50% of patients with AMH dipoles showed evidence of bitemporal affection on interictal and ictal EEG. Nine patients underwent epilepsy surgery so far. Whereas all five patients with AMV dipoles became completely seizure-free postoperatively (Class Ia), two out of four patients with AMH dipoles experienced persistent auras (Class Ib). This difference, however, was not statistically significant. We therefore conclude that combined MEG/EEG dipole modeling can identify subcompartments of the temporal lobe involved in epileptic activity and may be helpful to differentiate between subtypes of mesial temporal lobe epilepsy noninvasively.     

Fast oscillations associated with interictal spikes localize the epileptogenic zone in patients with partial epilepsy

Although interictal epileptic spikes are defined as fast transient activity, the spatial distribution of spike-related high-frequency power changes is unknown. In this study, we localized the sources of spike-locked power increases in the beta and gamma band with magnetoencephalography and an adaptive spatial filtering technique and tested the usefulness of these reconstructions for determining the epileptogenic zone in a population of 27 consecutive presurgical patients with medication refractory partial epilepsies. The reliability of this approach was compared to the performance of conventional MEG techniques such as equivalent current dipole (ECD) models. In patients with good surgical outcome after a mean follow-up time of 16 months (Engel class I or II), the surgically resected area was identified with an accuracy of 85% by sources of spike-locked beta/gamma activity, which compared favorably with the accuracy of 69% found for ECD models of single spikes. In patients with a total of more than 50 spikes in their recordings, the accuracies increased to 100% vs. 88%, respectively. Imaging of spike-locked beta/gamma power changes therefore seems to be a reliable and fast alternative to conventional MEG techniques for localizing epileptogenic tissue, in particular, if more than 50 interictal spikes can be recorded.     

Magnetoencephalographic yield of interictal spikes in temporal lobe epilepsy. Comparison with scalp EEG recordings

To compare magnetoencephalography (MEG) with scalp electroencephalography (EEG) in the detection of interictal spikes in temporal lobe epilepsy (TLE), we simultaneously recorded MEG and scalp EEG with a whole-scalp neuromagnetometer in 46 TLE patients. We visually searched interictal spikes on MEG and EEG channels and classified them into three types according to their presentation on MEG alone (M-spikes), EEG alone (E-spikes), or concomitantly on both modalities (M/E-spikes). The M-spikes and M/E-spikes were localized with MEG equivalent current dipole modeling. We analyzed the relative contribution of MEG and EEG in the overall yield of spike detection and also compared M-spikes with M/E-spikes in terms of dipole locations and strengths. During the 30- to 40-min MEG recordings, interictal spikes were obtained in 36 (78.3%) of the 46 patients. Among the 36 patients, most spikes were M/E-spikes (68.3%), some were M-spikes (22.1%), and some were E-spikes (9.7%). In comparison with EEG, MEG gave better spike yield in patients with lateral TLE. Sources of M/E- and M-spikes were situated in the same anatomical regions, whereas the average dipole strength was larger for M/E- than M-spikes. In conclusion, some interictal spikes appeared selectively on either MEG or EEG channels in TLE patients although more spikes were simultaneously identified on both modalities. Thus, simultaneous MEG and EEG recordings help to enhance spike detection. Identification of M-spikes would offer important localization of irritative foci, especially in patients with lateral TLE.     

双侧颞叶海马病变致药物难治性癫的外科治疗

目的探讨双侧颞叶海马病变致药物难治性癫的外科手术治疗方法及效果。方法 5例MRI显示双侧颞叶病变的患者,临床症状、核磁共振成像（MRI）、长程视频脑电监测（V-EEG）及正电子发射断层显像-计算机断层显像（PET-CT）等检查均不能定位起源病灶,行MRI引导立体定向下双侧海马深部电极置入术,对术后V-EEG,综合分析结果,确定起源病灶侧别后行手术治疗。结果术后随访半年以上,按照Engel的疗效判断标准：Ⅰ级4例（行起源侧前颞叶海马杏仁核切除术）,Ⅱ级1例（行起源侧海马神经调控治疗）。结论对双侧颞叶海马病变致药物难治性癫,通过立体定向下双侧海马深部电极置入术及术后长程V-EEG方法,综合分析结果能较准确确定癫起源灶,同时也能成功指导外科手术。     

单光子断层扫描、脑电图、核磁共振对致痫灶定位的研究

目的探讨单光子断层扫描(SPECT)、脑电图(EEG)、核磁共振(MRI)对致痫灶定位的价值.方法对40例临床确诊的癫痫患者进行SPECT、MRI、EEG等检查,比较三种检查方法对致痫灶定位的准确性.结果 EEG(包括长程监测)特异性异常34例,具有定侧定位意义的30例,定位率75%(30/40);SPECT在发作间歇期定位率为47% (19/40) ;MRI定位率为 25%(10/40).EEG对致痫灶的定侧定位率明显高于SEPCT及MRI,组间差异有统计学意义(Q=30.1,P＜0.01).结论 EEG在致痫灶定位方面是一种敏感、经济、便捷又安全的检查方法.结合SEPCT及MRI可提高对致痫灶定位的准确性.