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.     

伴有结构性病变颞叶癫(癎)的外科治疗

目的:对伴有结构性病变颞叶癫患者的外科治疗进行回顾性分析,探讨术前评估、手术方式和术中监测对病灶切除和术后癫控制的意义。方法:伴有结构性病变颞叶癫患者74例,术前进行全面详细评估,并进行病灶和致灶定位,术中在EcoG描记辅助下行病灶+致灶切除,术后随访6-48月。结果:术前V-EEG检查异常者59例(80%),MRI检查阳性者70例(95%),余4例行PET检查示颞叶局部代谢减低;术中EcoG描记异常放电者61例(82%);术后随访EngelⅠ级51例(70%),EngelⅡ级13例(18%),EngelⅢ级5例(7%),EngelⅣ级5例(7%)。结论:对伴有结构性病变颞叶癫患者术前进行全面评估,联合神经影像学检查、V-EEG、临床表现和其它术前评估手段对病灶和癫灶定位具有重大意义。在神经影像学和电生理指导下,行病变切除术+致灶切除术(或阻断性活动扩散的手术,如多处软膜下横切),可获得较好疗效。     

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.     

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。     

18F-FDG PET显像与EEG在颞叶癫痫致痫灶定位价值上的对比研究

目的：通过对62例难治性癫痫患者进行前瞻性研究,对18F-FDG PET显像与EEG在颞叶癫痫致痫灶定位上的价值进行对比研究。方法：对62例临床确诊颞叶癫痫并接受手术治疗的患者进行前瞻性研究。所有患者均进行发作间期PET-CT脑显像检查和长程/视频EEG检查,细致分析图像,并将所得检查结果与术后病理进行比较,利用统计学方法对二者的诊断准确率进行对比分析。结果：18F-FDG PET显像准确定位42例癫痫患者病灶位置,头皮EEG准确定位致痫灶30例,准确率分别为67.7%及48.4%,二者比较有显著统计学差异（P<0.05）。18F-FDG PET显像结果表现较多样,影像分析应细致、审慎。结论：发作间期PET-CT脑显像检查定位颞叶癫痫致痫灶优于长程/视频EEG检查,但因其价格较昂贵,临床可首选EEG定位癫痫,EEG定位困难时选择PET显像可明显提高致痫灶定位准确性。     

颅内肿瘤伴发癫的机制及外科治疗评价

临床上常见脑肿瘤伴发癫,但脑肿瘤与癫发生的关系仍很难确定。癫放电是脑皮层超同步放电的结果,无论是原发性还是继发性癫,都是大脑功能异常的表现,致灶脑生物电变化较其组织形态学变化更明显。因此,对颅内肿瘤伴发癫患者进行致灶定位时,既不同于单纯颅内占位病变者,也有别于其它顽固性癫患者。除了需要神经影像学检查发现病灶外,更要参考V-EEG的结果,结合临床表现和其它术前评估手段进行联合定位具有更大价值。在神经影像学和电生理指导下,行病变切除术+致灶切除术(或阻断性活动扩散的手术,如多处软膜下横切),可获得较好疗效,但并不能确保所有患者术后癫终止发作或得到明显改善。随着更多基础与临床研究的深入,人们对癫发病机制的理解将会更加深刻,对此类疾病的诊治也将会达到更高水平。     

癫痫灶定位的探讨

目前越来越多的顽固性癫痫患接受外科治疗，而癫痫外科治疗的关键是癫痫灶的准确定位。脑电图检查是癫痫外科术前综合评价的重要组成部分，普通脑电图（REEG）是诊断癫痫最基本、最重要的检查方法，但对癫痫灶的定位（定侧）诊断方面的敏感性、准确性及特异性均较低，确定诊断率只有60％左右，对致痫灶的定位诊断献报道为22％～45％，但是有较高的假阳性率出现。128导视频脑电图（VEEG）的出现，显提高了癫痫灶的空间分辨率，并且发作表达形式与异常脑电图统一结合起来，对癫痫分型及鉴别诊断和痫灶定位诊断十分重要，发作期VEEG记录是癫痫定位的必要前提。作选择53例癫痫手术患，通过MRI、MRS、术前REEG、128导长程VEEG监测及术中皮层脑电图，进行比较分析，为癫痫的术前诊断及定位提供更有价值的资料。     

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。     

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。     

联合应用SPECT、EEG、MRI定位癫痫致痫灶53例分析

目的探讨单光子发射计算机断层(SPECT)脑血流灌注显像联合动态脑电图和(或)视频脑电图、磁共振成像(MRI)检查在定位癫痫致痫灶中的意义.方法对53例癫痫患者于发作间期进行99mTc-ECD局部脑血流灌注显像,并与同期动态脑电图和(或)视频脑电图、MRI检查、术中皮层脑电图检查结果进行对比分析.结果 SPECT脑血流灌注显像诊断癫痫的阳性率为88.68%,与脑电图(EEG)检查的阳性率(86.79%)一致,但二者均明显高于MRI检查阳性率(33.96%),且STECT联合EEG检查,阳性率可提升至98.11%(52/53),明显高于SPECT或EEG单独检查的阳性率;在定位致痫灶过程中,SPECT脑血流显像与EEG在致痫灶的定位上具有良好的吻合性,其符合率(包括定位一致及基本一致者)为60.37%,明显高于SPECT与MRI检查的符合率(35.85%)及EEG与MRI的符合率(32.07%);经术中皮层脑电图检查证实SPECT定位致痫灶的准确率达83.33%,若与EEG、MRI联合分析则其定位准确率提升至95.8%(23/24).结论 SPECT脑血流灌注显像不仅能灵敏地检出癫痫灶,且能较准确地定位诊断癫痫灶,与EEG和MRI的联合应用可大大提高其诊断的灵敏度和定位的准确性.     

Localization of abnormal discharges causing insular epilepsy by magnetoencephalography

The insula, one of the five cerebral lobes of the brain, is located deep within the brain and lies mainly beneath the temporal lobe. Insular epilepsy can be easily confused and misdiagnosed as temporal lobe epilepsy (TLE) because of the similar clinical symptoms and scalp electroencephalography (EEG) findings due to the insula location and neuronal connections with the temporal lobe. Magnetoencephalography (MEG) has higher sensitivity and spatial resolution than scalp EEG, and thus can often identify epileptic discharges not revealed by scalp EEG. Simultaneous scalp EEG and MEG were performed to detect and localize epileptic discharges in two patients known to have insular epilepsy associated with cavernous angioma in the insula. Epileptic discharges were detected as abnormal spikes in the EEG and MEG findings. In Patient 1, the sources of all MEG spikes detected simultaneously by EEG and MEG (E/M-spikes) were localized in the anterior temporal lobe, similar to TLE. In contrast, the sources of all MEG spikes detected only by MEG (M-spikes) were adjacent to the insular lesion. In Patient 2, the sources of all MEG spikes detected simultaneously by EEG and MEG (E/M-spikes) were localized in the anterior temporal lobe. These findings indicate that MEG allows us to detect insular activity that is undetectable by scalp EEG. In conclusion, simultaneous EEG and MEG are helpful for detecting spikes and obtaining additional information about the epileptic origin and propagation in patients with insular epilepsy.     

幕上肿瘤伴发癫(癎)的精确定位和手术疗效分析

目的 探讨幕上肿瘤伴发癫(癎)的精确定位价值和手术治疗效果,研究肿瘤与致(癎)灶的关系.方法 对121例(胶质瘤Ⅰ级15例、Ⅱ级35例、Ⅲ～Ⅳ级12例,脑膜瘤32例,脑转移瘤10例,海绵状血管瘤15例,室管膜瘤2例)临床上以癫(癎)为首发症状的幕上肿瘤患者术前、术后癫(癎)发作情况等,临床资料进行回顾性分析.结果 采用术前影像和脑电结合定位、术中皮层脑电再次定位的方法,对肿瘤和癫(癎)灶同时切除,无手术死亡.癫(癎)发生率最高在额叶,最低在枕叶.癫(癎)灶与肿瘤的关系:位于同一部位者50例;致(癎)灶位于肿瘤一侧或近旁者28例;致(癎)灶位于肿瘤远隔部位(＞2 cm)25例;检测不到致痫灶者18例.失访18例,103例随访1～9年,31例术后早期仍有小发作,83例不再服抗癫(癎)药物癫(癎)症状完全消除.结论 在幕上肿瘤伴发癫(癎)患者中,致(癎)灶与肿瘤灶存在一定的差异性.在开颅切除肿瘤的同时必须明确致(癎)灶的位置和范围,一并切除才能达到良好的手术效果.     

Localizing epileptogenic regions in partial epilepsy using three-dimensional statistical parametric maps of background EEG source spectra

This preliminary study sought to localize epileptogenic regions in patients with partial epilepsy by analysis of interictal EEG activity utilizing variable resolution electromagnetic tomography (VARETA), a three-dimensional quantitative electroencephalographic (QEEG) frequency-domain distributed source modeling technique. The very narrow band (VNB) spectra spanned the frequency range 0.39 Hz to 19.1 Hz, in 0.39 Hz steps. These VNB spectra were compared to normative data and transformed to provide Z-scores for every scalp derivation, and the spatial distributions of the probable EEG generators of the most abnormal values were displayed on slices from a probabilistic MRI atlas. Each voxel was color-coded to represent the significance of the deviation relative to age appropriate normative values. We compared the resulting three-dimensional images to the localization of epileptogenic regions based on invasive intracranial EEG recordings of seizure onsets. The VARETA image indicated abnormal interictal spectral power values in regions of seizure onset identified by invasive monitoring, mainly in delta and theta range (1.5 to 8.0 Hz). The VARETA localization of the most abnormal voxel was congruent with the epileptogenic regions identified by intracranial recordings with regard to hemisphere in all 6 cases, and with regard to lobe in 5 cases. In contrast, abnormal findings with routine EEG agreed with invasive monitoring with regard to hemisphere in 3 cases and with regard to lobe in 2 cases. These results suggest that analysis of background interictal EEG utilizing distributed source models should be investigated further in clinical epilepsy.     

颅内电极监测癫痫发作初始期脑电定位意义

目的探讨颅内电极监测癫痫发作初始期脑电对致痫灶的定位价值。方法14例难治性癫痫患者,其临床、影像学检查及头皮脑电记录等不能精确定位致痫灶,经颅骨钻孔、埋置颅内深部和/或皮层电极,长程脑电监测并分析发作初始期脑电的异常放电节律和范围,对比术后病理学检查和随访结果,分析发作初期脑电定位致痫灶的准确性。结果记录到了47次临床发作。发作初期异常放电可分为4种形式:低幅快节律、尖波节律、高幅棘波节律和棘慢波节律。按异常放电范围可分为:局限性放电、区域性放电和广泛性放电。11例(78.5%)患者准确定位了致痫灶,术后癫痫发作消失(64.3%)或极少发作(14.2%),2例(14.2%)发作减少90%以上,1例(7.1%)术后无改善。结论颅内埋置电极脑电监测癫痫发作初始期异常放电形式、部位和异常放电范围是定位致痫灶可靠的方法。     

脑磁图与视频脑电图定位癫痫灶的结果比较

背景: 多数癫痫患者的癫痫发作经药物治疗可得到控制,但对于难治性癫痫患者来说,手术可能是一种治疗选择,正确定位癫痫患者的致痫灶是癫痫手术成功的基础.癫痫患者的术前评估包括视频脑电图、MRI、正电子发射计算机体层摄影/单光子发射计算机体层摄影和神经心理测试等.脑磁图作为一种新的无创性术前检测技术,已被许多国家用于癫痫外科手术计划和大脑功能的研究.目的:术前采用磁源成像技术进行对手术治疗的难治性癫痫患者进行致痫灶定位,并与无创性视频脑电图对比,参考手术效果,评估其定位价值.设计、时间及地点:回顾性病例分析,于2001-11/2005-12在广东三九脑科医院脑磁图室完成.对象:选择进行脑磁图检查618例的癫痫患者,采集其自发磁场信号进行单偶极子定位分析诊断.对其中149例MRI检查有结构改变、病史在2年以上者进行了手术治疗,病程2～35年,平均9.5年.方法:用148通道全头型脑磁系统(Magnes WH2500, 4-D Neuroimaging, San Diego, CA, USA)在磁屏蔽室采集脑自发磁场,采样频率为508.63 Hz,带通为1.0～100 Hz,采集30 min发作间歇期的自发脑磁,采用单个等效电流偶极子进行数据分析.分析结果最后重叠在MRI-T1加权像上,形成磁源成像.主要观察指标:术前视频脑电图、MRI和脑磁图结果及术后随访结果.结果:30 min发作间期的脑磁图检测到明显的癫痫样活动的敏感度为91%,并且大部分患者,其等效偶极子主要分布于结构性异常的边缘和邻近区域.与无创性视频脑电图(38.9%,58/149)相比,利用脑磁图可以对大部分MRI上有病变的患者(62.4%,93/149)进行精确定位并且能够确定切除区域.对资料完整的89 例患者进行了3～35个月的随访,平均随访9个月.89例患者中有72例(80.9%)术后未出现癫痫发作(EngelⅠ);7例(7.9%)癫痫发作极少或癫痫发作频率减少90%以上(Engel Ⅱ和 Engel Ⅲ);10例(11.2%)癫痫发作频率无明显减少(Engel Ⅳ和Engel Ⅴ),总有效率达88.8%(EngelⅠ～Ⅲ).结论:与无创性视频脑电图相比,利用脑磁图可以对大部分MRI上出现结构性病变的癫痫患者致痫灶进行精确定位,并且能够确定切除区域.     

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.     

Comparison of magnetoencephalographic spikes with and without concurrent electroencephalographic spikes in extratemporal epilepsy

Interictal spikes in patients with epilepsy may be detected by either electroencephalography (EEG) (E-spikes) or magnetoencephalography (MEG) (M-spikes), or both MEG and EEG (E/M-spikes). Localization and amplitude were compared between E/M-spikes and M-spikes in 7 adult patients with extratemporal epilepsy to evaluate the clinical significance of MEG spikes. MEG and EEG were simultaneously measured using a helmet-shaped MEG system with planar-type gradiometers and scalp electrodes of the international 10-20 system. Sources of E/M-spikes and M-spikes were estimated by an equivalent current dipole (ECD) model for MEG at peak latency. Each subject showed 9 to 20 (mean 13.4) E/M-spikes and 9 to 31 (mean 16.3) M-spikes. No subjects showed significant differences in the ECD locations between E/M- and M-spikes. ECD moments of the E/M-spikes were significantly larger in 2 patients and not significantly different in the other 5 patients. The similar localizations of E/M-spikes and M-spikes suggest that combination of MEG and EEG is useful to detect more interictal spikes in patients with extratemporal epilepsy. The smaller tendency of ECD amplitude of the M-spikes than E/M-spikes suggests that scalp EEG may overlook small tangential spikes due to background brain noise. Localization value of M-spikes is clinically equivalent to that of E/M-spikes.     

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.