颅内电极脑电监测定位致痫灶

目的 探讨颅内埋置电极脑电图(iEEG)监测定位致痫灶的意义及其安全性。方法 对38例经无创方法难以定位的难治性癫痫病人，采用颅骨钻孔或骨瓣开颅方法埋置硬膜下和(或)深部电极，行长程视频脑电监测定位致痫灶。根据术中致痫灶定位、术后病理、术后疗效和EEG复查结果分析iEEG监测定位致痫灶的准确性。结果8例埋置深部电极，13例埋置硬膜下电极，17例联合应用硬膜下电极和深部电极。颅内电极埋置4～22d，平均9d；脑电监测8～226h，平均128h．根据癫痫发作初始期iEEG，32例(84．2％)病人准确定位了致痫灶，无颅内出血和感染等严重并发症发生。结论选择性应用硬膜下和深部电极长程视频脑电监测是一种安全、有效的检查方法；癫痫发作初始期异常放电的节律和范围是可靠的致痫灶定位指标．     

长程颅内电极记录定位致痫灶的效果分析

目的 讨论应用颅内埋藏电极进行长程视频脑电(Video-EEG)监测，对于致痫灶的定位作用。方法 应用立体定向技术，向颅内可疑部位植入深部电极和／或硬膜下条状电极。采用DaVinci系统，进行长程视频脑电监测，记录发作间期及发作期EEG变化，确定癫痫起源部位。在皮层电极脑电图(ECoG)监测下，手术切除致痫灶或行立体定向毁损术。结果 本组17例患者颅内电极埋藏时间4～17天，平均9天。各例均记录到明确的发作间期异常放电和／或发作期EEG变化。手术切除致痫灶16例(联合胼胝体切开术1例)；行双侧杏仁核毁损术1例。术后复查Vidoo-EEG，显示痫性放电基本消失15例，改善2例(集中于手术对侧1例)。按照Engel术后效果分级：Ⅰ级15例，Ⅲ级1例，Ⅳ级1例。所有病例均未出现因长时间埋藏颅内电极引起的并发症。结论 在致痫灶定位困难的难治性癫痫患者中，应用埋藏式颅内深部电极和／或硬膜下条状电极，进行长程颅内电极记录，可以精确定位致痫灶，可改变外科治疗计划，从而提高了癫痫的治愈率及手术成功率。     

额叶癫痫的特点及手术治疗

目的 :分析额叶癫痫的临床特征、发作期及发作间期脑电图特点 ,探讨额叶癫痫手术治疗。方法 :应用视频脑电图对 9例额叶癫痫患者进行长程监测 ,并对其中 6例记录颅内脑电图。分析癫痫发作的临床表现及脑电图特点 ,定位致痫灶 ,行手术切除。结果 :额叶癫痫的发作特点为 :发作频繁而短暂 ,以睡眠期发作为主 ,常见过度运动 ,姿势性强直 ,发声等发作症状。发作期可见棘波节律 ,广泛低幅快活动 ,节律性慢波等特征性脑电活动。颅内电极记录可清晰显示异常脑电活动的发作起源及扩散情况 ,有助于定位致痫灶。手术切除病灶及致痫灶 ,效果满意。结论 :额叶癫痫是一组具有特征性的癫痫综合征 ,颅内电极记录有助于揭示其脑电活动变化。对于难治疗性额叶癫痫 ,准确定位致痫灶是手术成功的关键。     

6例磁共振阴性额叶癫痫患者致痫灶定位研究

目的探讨硬膜下电极脑电图(ECo G)监测对磁共振阴性癫痫患者致痫灶的定位作用。方法对经临床、影像学和头皮EEG检查不能确定致痫灶部位的6例难治性额叶癫痫患者,植入硬膜下条状电极进行视频EEG监测,观察颅内电极发作期及发作间期EEG变化,结合头皮EEG、临床发作结果对癫痫灶进行综合定位;术后随访,评估致痫灶定位的准确性。结果 6例患者颅内电极埋藏时间为2~5 d,每例监测到2次临床发作并记录发作间期和发作期的异常放电活动。5例患者发作期颅内电极EEG均能准确定位,5例显示一侧局灶性放电起源,1例患者显示双侧放电起源。术后按Engel疗效分级:EngelⅠ级4例(57.1%),EngelⅡ级1例(14.3%),随访不满1年的按谭氏术后效果分级,达到了满意。结论颅内电极EEG监测可为癫痫手术治疗提供可靠的病灶定位依据。     

视频脑电图结合磁共振扫描对颞叶癫痫术前定位的探讨

目的 探讨视频脑电图及磁共振扫描对颢叶癫痫术前定位的准确性.方法 回顾分析146例颞叶癫痫病例,术前均行长程视频脑电图(V/EEG)监测及磁共振扫描(MRI),发作时V/EEG所示的痫样放电部位与MRI检查所发现的病变同侧时,将此侧颞叶作为癫痫灶颞叶;MRI未见异常,则根据三次以上发作时V/EEG定侧.所有患者经术中皮层脑电图和深部脑电监测后,行前颞叶切除术.结果 术中皮层脑电图及深部脑电监测均发现有痫样放电,与术前V/EEG监测吻合.术后102例(70%)癫痫发作完全消失,显著改善35例(24%),良好6例(4%),无改善3例(2%).结论 V/EEG结合MRI对颞叶癫痫术前能进行准确定位.     

颅内电极脑电监测定位致癇灶

目的探讨颅内埋置电极脑电图(iEEG)监测定位致灶的意义及其安全性。方法对38例经无创方法难以定位的难治性癫病人,采用颅骨钻孔或骨瓣开颅方法埋置硬膜下和(或)深部电极,行长程视频脑电监测定位致灶。根据术中致灶定位、术后病理、术后疗效和EEG复查结果分析iEEG监测定位致灶的准确性。结果8例埋置深部电极,13例埋置硬膜下电极,17例联合应用硬膜下电极和深部电极。颅内电极埋置4～22d,平均9d;脑电监测8～226 h,平均128h。根据癫发作初始期iEEG,32例(84.2%)病人准确定位了致灶,无颅内出血和感染等严重并发症发生。结论选择性应用硬膜下和深部电极长程视频脑电监测是一种安全、有效的检查方法;癫发作初始期异常放电的节律和范围是可靠的致灶定位指标。     

脑电图影像融合技术定位致痫灶

目的探讨无创性脑电图影像融合技术对致痫灶定位作用.方法对4例临床确诊为癫痫的患者,术前视频脑电监测有异常放电,脑电图异常部位分别在右额颞、左颞、右中央顶区和右顶枕部.根据脑电图表现和脑电地形图分析结果,建立单或多偶极子模型.最后将标准头颅MRI模型与偶极子模型融合,确定致痫灶对应的解剖位置和空间坐标.结果致痫灶对应的解剖位置1例在右额中回的中部,1例在左颞后部皮质,1例定位在右侧中央沟,1例在右顶上小叶.偶极子参数随时间变化可反映异常脑电在脑内的传播方向.结论高分辨率三维MRI影像与定量脑电图分析的信息融合,可以直观地显示致痫灶的位置及异常放电传播方向,与真实头颅模型的融合无疑更会提高致痫灶手术前定位,对减少有创性检查,深部电极的准确放置也能起到促进作用.     

偶极子定位在癫痫术前定位诊断中的应用

目的 联合应用常规长程视频脑电图(video electroencephalography)、偶极子定位(dipole localization method)、颅内皮层电极和深部电极脑电图(electrocorticography and depth electrodes,EEG)对致痫灶进行定位,比较VEEG、DLM与ECoG and DEEG的符合情况,探讨偶极子定位技术在癫痫患者术前定位诊断中的价值.方法 收集30例已经确诊为癫痫的患者,分别进行常规长程视频脑电图、偶极子定位、颅内皮层电极和深部电极脑电图检查,比较常规EEG、偶极子定位技术与颅内EEG定位的一致性.结果 偶极子定位技术的符合率明显高于常规EEG,二者相比有显著性差异(P＜0.05);额叶癫痫、颞叶癫痫在各项术前定位检查中符合情况的比较均无显著性差异(P＞0.05).结论 偶极子定位技术是一种无创性定位方法,对局灶性癫痫有明确的定位意义,对于常规长程视频脑电图检测为单一病灶者,可替代侵入性颅内电极检查.     

颅内电极监测技术在癫痫手术中的应用

目的探讨颅内电极监测技术在难治性癫痫外科治疗中的应用价值。方法对头皮脑电图及影像学等非侵袭性检查难以确定致痫灶或致痫灶与重要功能区关系密切的51例难治性癫痫患者,行颅内电极埋置术,长程视频脑电图监测确定致痫灶,并行脑皮层电刺激功能区测定,再次手术切除致痫灶。结果术后致痫灶切除效果按Engel分级：I级32例,Ⅱ级13例,Ⅲ级5例,Ⅳ级1例。术后发生头皮愈合不良3例,延长住院时间后治愈。无脑脊液漏及永久性神经功能缺失发生。结论颅内电极监测可以精确定位致痫灶,皮层电刺激术对脑功能区定位可靠、方便,故对于采用非侵袭性检查不能明确致痫灶或致痫灶与重要功能区关系密切的难治性癫痫患者,颅内电极监测结合皮层电刺激术可以提高其治愈率,并有效降低并发症发生率。     

立体定向颅内脑电图在难治性癫痫治疗中的价值(附30例临床分析)

目的探讨立体定向颅内脑电图技术(SEEG)在难治性癫痫术前评估及癫痫灶定位中的作用与价值。方法回顾性分析中国医科大学航空总医院癫痫中心对于头皮脑电、电子计算机断层扫描(computed tomography, CT)、头颅磁共振(MRI)难以定位的药物难治性癫痫患者30例,根据其临床和术前影像学检查结果,设计SEEG方案并进行电极置入,长程记录发作3次以上并给予电刺激,结合发作间期及发作期深部脑电图确定致痫灶,手术切除后随访患者发作改善情况。结果 15例患者监测到局灶性发作,13例监测到区域性发作,2例患者监测到频繁全面性发作,30例患者均无电极植入后并发症,其中28例参照颅内脑电图结果行外科手术治疗,术后随访6～18个月,癫痫发作消失18例,5例缓解90%,5例缓解50%以上,无手术并发症。结论立体定向颅内脑电图在头皮脑电及磁共振难以明确致痫灶的难治性癫痫治疗中有重要的地位,为癫痫外科提供定位诊断价值,提高手术效果,减少手术并发症。     

27例学龄前难治性颞叶癫痫患儿临床报道

目的探讨学龄前难治性颞叶癫痫患儿影像学、电生理特点及手术方法和疗效。方法回顾性分析解放军联勤保障部队第九八八医院神经外科中心自2014年6月至2019年1月行手术治疗的27例学龄前难治性颞叶癫痫患儿资料,术前评估结合临床发作表现,MRI、磁共振波谱分析(MRS)、正电子发射断层扫描(PET-CT)等影像资料,以及发作间期和发作期视频脑电图(VEEG)资料;术中应用皮层脑电图(ECoG)与深部电极监测定位异常放电区域,指导手术切除致痫灶范围。术后采用Engel分级评估疗效。结果27例患儿均有典型颞叶癫痫临床表现,MRI发现一侧颞叶及海马异常信号影,发作间期及发作期VEEG提示异常放电起始于一侧额颞部。术中ECoG及深部电极监测均发现颞叶明显持续或阵发性尖波、棘波、棘慢复合波等癫痫样放电。27例患儿均采用标准前颞叶+病灶切除+周边异常放电颞叶皮质扩大切除术,其中2例患儿切除部分岛叶长回及额盖皮质热灼处理。随访6个月,EngelⅠ级患儿22例,EngelⅡ级患儿3例,EngelⅢ级患儿2例。结论早期手术、术中ECoG与深部电极联合监测下适度扩大切除范围是改善学龄前难治性颞叶癫痫患儿手术疗效的关键因素。     

EEG dipole source localisation of interictal spikes acquired during routine clinical video-EEG monitoring

OBJECTIVE: We investigated the feasibility of electroencephalography (EEG) dipole source localisation of interictal epileptiform discharges from data acquired during routine clinical inpatient video-EEG monitoring (VEM) and compared a 19-channel 'routine montage' with a 29-channel 'surgical montage' that includes an additional row of 10 inferior temporal electrodes. METHODS: Twenty consecutive patients who had VEM for the presurgical evaluation of medically refractory partial epilepsy were screened. Thirteen of the patients had focal interictal spikes recorded, and in 11 (85%) these were technically satisfactory for source localisation. Fourteen spike foci were analysed as 3 patients had bilateral independent spikes. EEG data was acquired with 29 electrodes including an inferior temporal row (surgical montage). For comparison, the 10 additional electrodes were excluded from analysis (routine montage). Using NEUROSCAN Source 2.0 software, a computed dipole source localisation of averaged spikes was performed utilising a magnetic resonance imaging-based finite element model. Dipole localisation was compared with that of the Comprehensive Epilepsy Program (CEP) evaluation. RESULTS: Using the surgical montage dipole source localisation was consistent with the CEP spike localisation for 13/14 spikes (93%, P<0.005), compared with only 5/14 spikes (36%) using the routine montage. CONCLUSIONS: Data derived from routine clinical inpatient VEM using a routine montage can yield accurate EEG dipole source localisation, but significantly more accurate localisation is obtained using the surgical montage.     

Temporal lobe epilepsy following maintenance electroconvulsive therapy—Electrical kindling in the human brain?

Maintenance electroconvulsive therapy (ECT) is sometimes prescribed for refractory psychiatric conditions. We describe five patients who received maintenance ECT and developed florid temporal epileptiform abnormalities on electroencephalography (EEG) despite no history of epilepsy and normal neuroimaging. All patients had received regular ECT for at least 8 months. Three patients had clinical events consistent with epileptic seizures, and video‐EEG monitoring captured electrographic seizures in two patients. After cessation of ECT the EEGs normalized in all patients, and no further clinical seizures occurred. Maintenance ECT may predispose to epilepsy with a seizure focus in the temporal lobe.     

Diagnostic utility of video EEG monitoring in paroxysmal events

Objectives A retrospective study was conducted to evaluate clinical usefulness of video EEG monitoring in patients with suspected epileptic seizures.
Material and methods A total of 444 patients who had diagnostic video EEG from January 1989 to December 1992 were studied after excluding those with known medically refractory focal epilepsy undergoing presurgical evaluation. Most were outpatients and had video EEG monitoring during normal working hours over 1–5 days.
Results The procedure had a success rate of 73%; characteristic events were captured and categorized in 53% of the patients. Patients with an event frequency of at least one per week or those who had events characterized by motor manifestations showed a higher yield. Thirty-two percent of the patients had psychogenic seizures. Thirty-four percent of the patients had either epileptic seizures recorded during the study or showed clear-cut interictal epileptiform abnormalities providing strong evidence of underlying epileptic process.
Conclusion In patients with frequent paroxysmal events, a video EEG study provides diagnostically critical information. It can be performed usually as an outpatient investigation.     

Understanding the pathophysiology of reflex epilepsy using simultaneous EEG‐fMRI

Measuring neuro‐haemodynamic correlates in the brain of epilepsy patients using EEG‐fMRI has opened new avenues in clinical neuroscience, as these are two complementary methods for understanding brain function. In this study, we investigated three patients with drug‐resistant reflex epilepsy using EEG‐fMRI. Different types of reflex epilepsy such as eating, startle myoclonus, and hot water epilepsy were included in the study. The analysis of EEG‐fMRI data was based on the visual identi?cation of interictal epileptiform discharges on scalp EEG. The convolution of onset time and duration of these epilepsy spikes was estimated, and using these condition‐specific effects in a general linear model approach, we evaluated activation of fMRI. Patients with startle myoclonus epilepsy experienced epilepsy in response to sudden sound or touch, in association with increased delta and theta activity with a spike‐and‐slow‐wave pattern of interictal epileptiform discharges on EEG and fronto‐parietal network activation pattern on SPECT and EEG‐fMRI. Eating epilepsy was triggered by sight or smell of food and fronto‐temporal discharges were noted on video‐EEG (VEEG). Similarly, fronto‐temporo‐parietal involvement was noted on SPECT and EEG‐fMRI. Hot water epilepsy was triggered by contact with hot water either in the bath or by hand immersion, and VEEG showed fronto‐parietal involvement. SPECT and EEG fMRI revealed a similar fronto‐parietal‐occipital involvement. From these results, we conclude that continuous EEG recording can improve the modelling of BOLD changes related to interictal epileptic activity and this can thus be used to understand the neuro‐haemodynamic substrates involved in reflex epilepsy.     

Absence of seizures despite high prevalence of epileptiform EEG abnormalities in children with autism monitored in a tertiary care center

PURPOSE: Children with autism are commonly referred for video-EEG monitoring to determine the precise nature of their seizure-like events. METHODS: We studied 32 children with autism by using continuous video-EEG telemetry (VEEG) monitoring at a tertiary care referral center. RESULTS: Of the 32 total patients, 22 were primarily referred for seizure evaluation and 10 for 24-h interictal EEG recording. Studies in two additional patients were prematurely terminated because of intolerance (they are not included in the analyses). The median monitoring duration was 1 day (range, 1-7 days). Of 22 patients referred for seizure evaluation, 15 had recorded events, but none was an epileptic seizure; the other seven patients had no recorded events. Interictal epileptiform EEG abnormalities were detected in 19 (59%) of 32 patients. These abnormalities included focal sharp waves (in eight patients), multifocal sharp waves (in six patients), generalized spike-wave complexes (in 11 patients), and generalized paroxysmal fast activity/polyspikes (in two patients). Focal/multifocal and generalized epileptiform abnormalities coexisted in six patients. Notably, 11 (73%) of the 15 patients with nonepileptic events had interictal epileptiform EEG abnormalities. CONCLUSIONS: Video-EEG evaluation of children with autism reveals epileptiform EEG abnormalities in the majority. However, many recorded seizure-like events are not epileptic, even in children with epileptiform EEG abnormalities.     

Latency to first spike in the EEG of epilepsy patients.

BACKGROUND: Routine EEGs in individuals with epilepsy have interictal spikes in 56% of cases. The availability of prolonged EEG has changed the use of EEG in the assessment of epilepsy. OBJECTIVE: To determine the time to first epileptiform activity on EEG in patients with epilepsy. This data will help optimize the duration of electrographic assessment for interictal activity in epileptic individuals. METHODS: 46 consecutive patients aged 10 years or older with epilepsy were evaluated. Individuals with seizures in the prior 24h or with acute symptomatic seizures were excluded. Continuous EEG (for 1-7 days) was analyzed to find the first definite epileptiform activity and the latency assessed. RESULTS: 37% of the patients had epileptiform activity in the first 20min of the continuous recording (duration of a routine EEG). 89% had epileptiform activity within 24h. The yield drops beyond 24h. 8% of the individuals had no epileptiform activity even after 72h. CONCLUSIONS: The study suggests the need to consider a change in EEG strategy to assess interictal epileptiform activity. The greatest probability of capturing an interictal abnormality within 20min was in individuals with generalized epilepsy. In individuals with suspected epilepsy in whom electrographic interictal spike confirmation is deemed necessary, after a first nonspecific or normal routine EEG, a 24h EEG should be the next step in the electrographic assessment. This study suggests that there may not be much benefit in monitoring for durations longer than 24h, unless capturing a seizure is the intent.     

Visualizing prolonged hyperperfusion in post-stroke epilepsy using postictal subtraction SPECT

Diagnosis of post-stroke epilepsy is often challenging because of a low incidence of epileptiform abnormalities on electroencephalography (EEG). Hence, this study evaluated whether postictal subtraction single-photon emission computed tomography (SPECT) could visualize epileptic activity and act as a diagnostic modality in post-stroke epilepsy. Fifty post-stroke epilepsy patients, who had undergone Tc-99m-ECD SPECT twice (postictal and interictal), were enrolled. The postictal hyperperfusion area was identified by subtraction (postictal–interictal) SPECT and classified into two distribution types: superficial or deep-seated. Laterality and distribution of postictal hyperperfusion on subtraction SPECT were compared with stroke lesions, seizure symptoms, and epileptiform EEG findings. Forty-three of the 50 patients (86%) had hyperperfusion on subtraction SPECT and 26 (52%) had epileptiform EEG findings. Subtraction SPECT showed prolonged postictal hyperperfusion despite the relatively long interval between seizure end and postictal SPECT (median: 19.1 h, range: 2.2–112.5 h). The laterality of the hyperperfusion area had a high concordance rate with the laterality of stroke lesions (97.7%), seizure symptoms (91.9%), and epileptiform EEG findings (100%). Scalp EEG identified epileptiform activity more frequently in superficial type of SPECT, but less frequently in deep-seated type (both, P = 0.03). Postictal SPECT can be complementary to scalp EEG in endorsing the diagnosis and location of post-stroke epilepsy.     

发作间期颞叶癫痫的18F-FDG PET 显像研究

目的：采用诊断试验评价方法评估发作间期^18F-FDG PET显像对颞叶癫痫定性和病业定位的诊断价值，探讨其外科治疗的意义。方法：26例CT或MRI检查正常，经临床及脑电图诊断的颞叶癫痫患者在同期进行发作间期^18F-FDG PET脑显像，图像通过目测和半定量的方法进行分析，PET显示的低代谢区行皮层脑电图（EcoG）或深部脑电图（DEEG）描记以评估^18F-FDG PET检测癫痫灶的特异性，17例定位明确的单侧颞叶癫痫行前颞叶切除术，术手进行随访。2例PET未检出癫痫灶，7例DEEG定位双侧病灶未行手术治疗。结果：26例颞叶癫痫中，发现^18F-FDG PET对癫痫灶检出的灵敏度为92%（24/26），特异度为87%(21/24)。结论：从颞叶癫痫的定性定位诊断来看，发作间期^18F-FDG PET脑显像对癫痫灶的检出率较高，但^18F-FDG PET显示的低代谢区与癫痫灶的位置并非完全重叠，尚需要其他的诊断措施加以肯定，^18F-FDG PET和皮层脑电图或深部脑电图对癫痫病灶定位的一致性是手术成功的关键。     

脑磁图在癫外科灶定位中的作用(附47例分析)

目的探讨脑磁图(MEG)在癫外科灶定位中的临床价值。方法回顾性分析47例行MEG及头皮视频脑电图(V-EEG)检查的难治性癫病人的病例资料。其中39例接受手术治疗;10例开颅行皮质脑电(ECoG)监测。将MEG的结果与发作期及发作间期V-EEG及ECoG结果进行对比分析。结果MEG显示灶位置与发作间期和发作期V-EEG结果吻合率分别达76.6%和80.9%,与发作间期和发作期ECoG的吻合率均为80.0%。39例手术病人中,术后EngelⅠ级21例,Ⅱ级10例,Ⅲ级8例;其中29例拟切除的区域涉及到解剖学意义上的功能区,术中根据MEG显示的功能区位置进行了适当的处理,术后神经系统功能障碍未加重。结论MEG为无创性检查,对高频放电检出率较高,弥补了脑电在介质衰减方面的不足;同时也有利于癫外科治疗中对功能区的保护。