脑磁图癫(癎)灶和皮层功能区定位在癫(癎)外科的应用

目的 探讨脑磁图在癫(癎)外科术前评估中的应用价值.方法 回顾性分析216例手术治疗顽固性癫(癎)病例,术前应用脑磁图辅助定位皮层癫(癎)灶及重要皮质功能区范围,其中18例将脑磁图与神经导航系统结合.结果 本组216例患者,按照Engel癫(癎)疗效分级,Ⅰ级71.75%,Ⅱ级10.19%,Ⅲ级8.80%, Ⅳ级9.26%.脑磁图癫(癎)灶定位与术中皮质脑电图定位符合率87.9%.无一例出现手术后永久神经功能障碍.结论 脑磁图是无创确定癫(癎)灶和功能区皮质空间位置关系的重要工具,脑磁图结合神经导航术前和术中的皮质功能区定位方法应用可使癫(癎)外科实现微侵袭和精确手术.     

脑磁图癫灶和皮层功能区定位在癫外科的应用

目的 探讨脑磁图在癫外科术前评估中的应用价值。方法 回顾性分析216例手术治疗顽固性癫病例,术前应用脑磁图辅助定位皮层癫灶及重要皮质功能区范围,其中18例将脑磁图与神经导航系统结合。结果 本组216例患者,按照Engel癫疗效分级,Ⅰ级71.75%,Ⅱ级10.19%,Ⅲ级8.80%,Ⅳ级9.26%。脑磁图癫灶定位与术中皮质脑电图定位符合率87.9%。无一例出现手术后永久神经功能障碍。结论 脑磁图是无创确定癫灶和功能区皮质空间位置关系的重要工具,脑磁图结合神经导航术前和术中的皮质功能区定位方法应用可使癫外科实现微侵袭和精确手术。     

脑磁图定位顽固性癫痫手术治疗51例临床分析

目的　探讨脑磁图在顽固性癫痫术前评估的价值。方法　术前对 5 1例顽固性癫痫患者行脑磁图、磁共振及视频脑电检查 ,结合术中皮层脑电图分别进行选择性海马杏仁核切除术、标准前颞叶切除术及致痫灶切除术等手术 ;并用脑磁图定位神经导航下手术切除致痫灶 2例 ,神经导航下海马杏仁核切除 2例。结果　术后发作完全停止的占 76 5 % ,发作减少 >75 %的占 11 8% ,发作减少>5 0 %的占 5 8% ,发作减少不足 5 0 %的占 5 8% ;脑磁图与视频脑电及皮层脑电图的定位符合率分别为 82 %和 96 % ;脑磁图对内侧颞叶癫痫的定位敏感性较差 ;脑磁图定位导航手术可在切除致痫灶的同时保护脑的重要结构。结论　脑磁图是一项灵敏的无创性癫痫灶定位方法 ,是癫痫外科术前评估中的一项技术突破     

幕上脑海绵状血管瘤并癫痫的手术策略(附57例临床分析)

目的探讨伴有癫痫病史的幕上脑海绵状血管瘤(CA)的手术策略。方法回顾性分析57例伴有癫痫病史的幕上脑海绵状血管瘤患者的资料,依据癫痫发作情况将其分为顽固组(41例)和偶发(或初发)组(16例)。顽固组内行单纯病变切除者15例,行病变切除及致痫灶扩展切除者26例。分别分析其病灶部位、临床表现、切除范围与术后随访结果。结果57例患者均行显微手术治疗,40例部位深在,均运用导航指引术中定位。本组无远期神经功能障碍,术后癫痫控制EngleⅠ级45例(81.8%),EngleⅡ级4例(7.3%),EngleⅢ级4例(7.3%),EngleⅣ级2例(3.6%)。结论①幕上脑海绵状血管瘤伴发癫痫的患者应尽早行手术治疗。②对于初发或偶发癫痫患者,手术切除病变及周围含铁血黄素沉积带即可获得满意的癫痫控制;对于顽固性癫痫患者,在前者基础上加行致痫皮层切除或脑叶切除将获得更理想的效果。③脑磁图检查结合EEG对术前癫痫灶定位有较大帮助。     

神经导航引导海马病灶切除联合皮质热灼治疗顽固性颞叶内侧癫痫

目的探讨神经导航引导、皮质电极监测下对海马病灶进行致痫灶切除,辅助以皮质痫灶横纤维热灼术治疗顽固性颞叶内侧癫痫的临床价值。方法通过对16例海马病灶的顽固性癫痫的病人,术前进行24小时脑电图描记定位致痫灶,手术前进行磁共振扫描,数据输人神经导航系统,手术当天进行导航注册配准．术中进行颞叶皮质电极描记,并在导航棒引导下找寻海马病灶,完整切除并辅以皮质热灼治疗致痫灶。结果术后0．5～3年内随访,按Engel癫痫疗效分级：发作完全消失11例(68．8％),明显改善4例(25％),改善1例(6．2％)。结论神经导航有助于海马病灶的准确找寻与切除,在皮质电极监测下,辅助皮质热灼是治疗顽固性颞叶内侧癫痫的一种有效、安全的方法。     

局灶性皮质发育不良所致难治性癫痫的微创神经外科治疗

目的应用神经导航结合术中皮质电极描记,微创治疗局灶性皮质发育不良(focal cortical dysplasia,FCD)所致的难治性癫痫。方法 26例局灶性皮质发育不良所致的难治性癫痫患者,术前常规使用CT、磁共振成像(magnetic resonanceimaging,MRI)、长程视频脑电图(digital video signal and electroencephalogram,VEEG)、磁共振波谱分析(MR Spectroscopy,MRS)等检查,如病灶位于功能区则行功能性磁共振成像(functional magnetic resonance imaging,fMRI)。术中通过神经导航确定的病灶与ECoG确定的致痫灶位置及范围进行对比,了解两者的吻合程度及差异,综合分析后精确并标记出癫痫波的起源位置和范围,将局灶性皮质发育不良病灶和周边的致痫皮质切除;如致痫灶位于功能区或附近,在保留功能区皮质的基础上,给予低功率皮质热灼。结果术后病理结果:26例患者病理标本符合FCD。术后患者无明显并发症出现。根据Engel术后效果分级进行评估,Ⅰ级23例,Ⅱ级2例,Ⅲ级1例。结论神经导航结合术中皮质电极描记在局灶性皮质发育不良所致的难治性癫痫手术中,具有定位准确、损伤少的优点,在切除致痫灶的同时能最大程度保护脑功能。     

脑磁图对非病灶性新皮质癫痫术前评估的价值

目的 研究非病灶性新皮质癫痫发作间期脑磁图(MEG)与手术切除范围一致性与预后的关系.方法 25例非病灶性新皮质癫痫,术前行发作间期MEG检测以及颅内视频脑电监测(i-VEEG),术后随访1年以上并运用Engel法评价预后.结果 术后总体无发作率(Engel IA) 36％ (9/25)、有效率(Engel Ⅰ级、Ⅱ级)68％(17/25).14例MEG与手术切除范围一致组术后8例无发作,无发作率57％(8/14),有效率71％ (10/14);11例不一致组,术后无发作率9％(1/11),有效率64％(7/11),一致组术后无发作率优于不一致组(P＜0.05).结论 非病灶性新皮质癫痫发作间期MEG与手术切除范围一致与术后无发作率有明确相关性.     

脑磁图在伴发癫痫的颅内肿瘤手术中的应用

目的探讨脑磁图在伴发癫痫的颅内肿瘤手术中的应用。方法应用CTF脑磁图系统对20例伴发癫痫的颅内肿瘤患者行术前致痫灶定位，术中结合神经导航系统和皮层脑电描记指导致痫灶的处理。结果16例肿瘤全切除，4例次全切除，致痫灶均获处理，术后癫痫停止发作20例；随访24～36个月，术后1月及15月各1例再次出现癫痫发作，余18例无发作，9例停药。结论伴发癫痫的颅内肿瘤，脑磁图能够较好的定位致痫灶，在切除肿瘤的同时指导致痴灶的处理。     

涉及中央区难治性癫痫的外科治疗

目的探讨涉及中央区难治性癫痫的手术治疗。方法3例患者术前除常规致痫灶评估外,还应用fMRI作皮质功能区定位。术中通过皮层EEG（ECoG）对致痫灶定位,通过皮层诱发电位（SEP）及皮质电刺激定位脑功能区,对位于功能区以外的致痫灶行切除性手术,功能区内的致痫灶行软脑膜下横行纤维切断术。结果术后无神经功能障碍,术后3月,2例病人无癫痫发作,1例偶有部分性发作;术后8月,1例无发作,1例偶有部分性发作,1例减少75%发作。结论术前功能区评估、术中电生理监测有助于保护皮质重要功能和提高手术癫痫控制率。     

脑磁图与神经导航结合在脑功能区肿瘤切除中的初步应用(附31例报道)

目的 探讨脑磁图功能区定位与神经导航结合在肿瘤神经外科的应用价值.方法 选择31例功能区肿瘤患者术前行脑磁图(Magnetoencephalography,MEG)确定肿瘤范围及相邻皮质功能区位置,将影像数据输入Brain-LAB导航系统工作站,进行三维重建并制定手术计划,标记肿瘤病灶及其临近重要功能区,应用显微外科技术切除病变,术后进行临床和影像学评价.结果 肿瘤全切除26例,次全切除2例,大部切除3例.术后新增一过性功能障碍8例.结论 MEG是一种无创检查方法,结合神经导航将病灶与功能区定位应用于肿瘤神经外科,能够有针对性地选择手术入路,并在术中更精确地保护功能区,从而使功能区损伤的机会大为减少.     

Lobar localization information in epilepsy patients: MEG--a useful tool in routine presurgical diagnosis

Epilepsy surgery is an established therapy for pharmacoresistant focal epilepsy. This study investigated the contribution of routinely used magnetoencepahlography (MEG) in addition to long term video-EEG-monitoring in presurgical evaluation. The distribution of localization results to anatomical lobes was compared with special focus to MEG spike localization results in cases without or with ambiguous EEG findings. A total of 105 consecutive patients with intractable focal epilepsy and epilepsy surgery after investigation by video-EEG-monitoring and MEG were included. The percentages of monolobar results were analysed and compared, especially with respect to the resection lobe. Postoperative outcome was used for further validation. No spikes were recorded on MEG in 30% (32 of 105). In cases with a diagnostic finding by the respective method, MEG localized in 82% (60 of 73 patients) within one anatomical lobe. Ictal EEG localized within one lobe in 72% (66 of 92 patients), interictal EEG in 60% (59 of 98 patients). In 25 of 105 patients (24%) no clear localization within one lobe was found either in interictal or in ictal EEG. In 11 of these cases MEG localized within the resection lobe. Six patients of these became seizure free, the other five had at least 50% reduction of their seizure rate 1 year after surgery. In summary MEG is a useful tool in the routine workup for epilepsy surgery contributing information to focus hypothesis in addition to video-EEG.     

磁源影像导航辅助显微手术治疗顽固性癫(癎)

目的探讨磁源影像引导的神经导航技术在显微手术治疗顽固性癫癎的作用。方法顽固性癫癎病人14例,术前行视频脑电图、磁共振、脑磁图等检查,综合评估确定致癎灶的位置。术中运用磁源影像引导的stealstation神经导航系统及皮层脑电图,进行显微手术。结果术中皮层脑电图与术前定位符合率100%,术后癎样放电消失9例明显好转5例。患者神经功能保持良好。10例随访疗效满意。结论致癎灶的定位需要综合分析,磁源影像是一重要的定位方法,神经导航的应用有助于癫癎的微侵袭手术。     

脑裂畸形继发难治性癫的微创外科治疗

目的探讨脑裂畸形继发难治性癫的致灶定位以及微创外科治疗方法。方法回顾性分析11例脑裂畸形继发难治性癫病人的临床资料,术前通过多模态神经影像和长程视频脑电图进行解剖与功能定位。在神经导航引导下使用皮质电极描记了解脑裂畸形病灶与癫波的关系,显微镜下将脑裂畸形的致灶切除。其中位于功能区的脑裂畸形,可使用功能MRI(fMRI)导航并辅以小功率皮质热灼。结果随访11例,时间12个月。术后癫发作完全消失9例,好转2例。结论多模态神经影像和长程视频脑电图可以对脑裂畸形继发的难治性癫进行致灶的解剖与功能定位,在保护脑功能的基础上将脑裂畸形的致灶切除是手术关键。     

Toward the substitution of invasive electroencephalography in epilepsy surgery.

The authors compared the localization accuracy of interictal magnetoencephalography (MEG) with ictal and interictal invasive video electroencephalography (VEEG) in identifying the epileptogenic zone in epilepsy surgery candidates. Forty-one patients, 29 with temporal lobe epilepsy (TLE) and 12 with extratemporal lobe epilepsy (ETLE), participated. Only patients with interictal changes during the MEG recordings were included. A comparison of the accuracy of invasive VEEG and MEG seizure zone identification was based on the degree of overlap between the location of the actual surgical resection and the zone identified by each method, and the success of surgery in reducing seizure activity. No statistical differences were observed between the accuracy of invasive VEEG and MEG in determining the location of the seizure zone across TLE and ETLE cases. Invasive VEEG and MEG localization judgments were correct in 54% and 56% of the cases, respectively. Separate group analyses suggested that MEG may be less beneficial relative to invasive VEEG in ETLE than TLE cases. MEG is of statistically equivalent accuracy to invasive VEEG, despite the fact that its use has not reached optimal conditions. The authors predict the replacement of the more invasive procedure with MEG in the near future for TLE cases, subsequent to the optimization of the conditions under which preoperative MEG is performed.     

The significance of ear plugging in localization-related epilepsy

PURPOSE: The localizing value of ear plugging in the treatment of auditory onset partial seizures, to our knowledge, has not been previously described. We propose that ear plugging is a clinical response to a sensory seizure manifested as an auditory hallucination and a tool for identifying the seizure focus in the auditory cortex on the superior temporal gyrus. METHODS: We report on three children who had prior epilepsy surgery for recurrent symptomatic localization-related epilepsy and who, subsequent to their surgery, displayed stereotyped unilateral or bilateral ear plugging at the onset of partial seizures. We studied scalp video electroencephalography (VEEG), magnetoencephalography (MEG), and magnetic resonance imaging (MRI) in all three. Additionally, we used electrocorticography (ECoG) in two patients, intracranial VEEG monitoring in one patient, and functional MRI language mapping in two patients. RESULTS: All three patients plugged their ears with their hands during auditory auras that localized to the superior temporal gyrus and were followed by partial seizures that spread to a wider field, as shown on scalp and intracranial VEEG. All three patients had MEG interictal discharges in the superior temporal gyrus. One patient who was nonverbal and unable to describe an auditory phenomenon plugged the ear contralateral to where temporal lobe-onset seizures and MEG interictal discharges occurred. CONCLUSIONS; Ear-plugging seizures indicate an auditory aura and may also lateralize seizure onset to the contralateral temporal lobe auditory cortex. Stereotyped behaviors accompanied by epileptic seizures in children who have poor communication skills are important in the seizure semiology of localization-related epilepsy.     

Entorhinal cortex atrophy in epilepsy patients exhibiting normal hippocampal volumes

OBJECTIVE: To determine whether MRI volumetric measurement of the entorhinal cortex could detect structural damage and lateralize the seizure focus in patients with temporal lobe epilepsy in whom no measurable hippocampal abnormalities were found. BACKGROUND: A reduction in the volume of the entorhinal cortex ipsilateral to the seizure focus in patients with intractable temporal lobe epilepsy and hippocampal atrophy was recently shown. METHODS: MRI volumetric analysis of the entorhinal cortex was performed using a T1-weighted three-dimensional gradient echo sequence in 24 control subjects and 22 patients with temporal lobe epilepsy and normal hippocampal volumes. Thirteen patients underwent surgery, with a mean postoperative follow-up of 36 months. RESULTS: Group analysis (multivariate analysis of variance) showed a reduction in the volume of the entorhinal cortex ipsilateral to the seizure focus in patients with left (p < 0.0001) and right temporal lobe epilepsy (p < 0.0001). Lateralization of the seizure focus could be done in 14 of 22 patients (64%) based on entorhinal cortex volumetry. CONCLUSION: Entorhinal cortex atrophy ipsilateral to the seizure focus supports the presence of structural damage in the mesial temporal lobe in patients with temporal lobe epilepsy and normal hippocampal volumes and emphasizes the participation of the entorhinal cortex in the pathogenesis of this disorder.     

Benefit of magnetic source localization in challenging refractory epilepsies

Background

About 23 million people worldwide suffer from medically refractory epilepsy. Surgery might be the best treatment option with a reasonable chance of seizure freedom. Surgical success depends on the exact definition of the epileptogenic zone (EZ). Magnetoencephalography (MEG) is one of the newer additions to the noninvasive presurgical work-up.

Objectives

This study gives an overview of the impact of MEG on the management of epilepsy patients, focusing on (1) the influence on presurgical evaluation, (2) the identification of patients with the greatest benefit, and (3) possible surgical outcome predictors.

Methods

An extensive Medline literature search was conducted for studies published from 1990.

Results

MEG is in clinical use in the presurgical evaluation of epilepsies for the identification of the EZ and outcome prediction. In cases of failed surgery, it serves as a means to locate the remaining epileptogenic cortex. The usefulness of MEG has been reported for a wide range of localizations including challenging areas like the insula. In cases of multiple possible culprit lesions, MEG can mark the epileptogenic lesion, whereas in cases of nonlesional magnetic resonance imaging (MRI) findings, MEG can pinpoint a lesional or nonlesional epileptogenic cortex area. The role of MEG in the presurgical evaluation of epilepsy was shown with rates of modified approaches in 20–35% of cases. This holds true especially for cases with extratemporal epilepsy.

Discussion

The value of MEG source localization is highest in extratemporal epilepsy, in MRI-negative or multilesional cases, if other modalities yield contradictory or inconclusive results, or in cases of suspected multifocal epilepsy. There is clear evidence that MEG yields nonredundant information and influences the therapeutic course of patients. Various patient groups likely to benefit from MEG were identified. Considering the poor chances of seizure freedom with continued medical treatment, these patients should not be denied source localization, which could result in surgery with favorable outcomes.

     

功能性磁共振导航结合皮质电极描记切除功能区及其附近的癫痫灶

目的探讨利用fMRI导航结合皮质电极描记切除功能区及其附近癫痫灶的临床疗效。方法回顾性分析11例癫痫灶起源于功能区及其附近的癫痫病人的手术经验。病人术前发作频率（2．63±1．68）次／月。术前利用fMRI检查确定功能区位置并与导航图像进行融合,术中使用皮质电极描记标记出癫痫波的位置,通过导航系统了解功能区与癫痫波起源的关系。在保留功能区皮质的基础上,将病灶和癫痫波起源处皮质切除,而位于功能区皮质上的癫痫波起源处则给予小功率皮质热灼。结果皮质发育不全8例,灰质异位症2例,脑外伤后局部皮质软化1例。术后随访6～12个月,癫痫发作完全消失9例,术后3-6d内发作1次2例,随后未再出现癫痫发作。术后未出现明显的神经功能损害加重的情况。术后3个月复查脑电图显示基本正常。结论fMRI导航结合皮质电极描记切除起源于功能区及其附近的癫痫灶是一种微侵袭的手术方法,在切除癫痫灶的同时能最大限度地保留功能区的神经功能。