颞叶占位性病变伴癫痫患者的脑电图特征及手术疗效

目的探讨颞叶占位性病变伴癫痫患者的脑电图癫痫样放电的分布特征及手术疗效。方法回顾性分析31例颞叶占位性病变伴癫痫患者术前脑电图及术后随访资料,其中囊性占位7例,海绵状血管瘤6例,胶质瘤16例,其他病变2例;均行病变完全切除术,大部分包括前颞叶及内侧结构切除。结果术前癫痫发作间期脑电图癫痫样波分布与病变位置关系：仅出现在病变侧颞叶12例（38．7％）,超出病变侧颞叶14例（45．2％）,完全不在病变侧颞叶3例（9．7％）;脑电图正常2例（6．4％）。监测中出现癫痫发作的17例患者中,病变侧颞叶起源12例（70．6％）,双侧颞叶起源1例（5．9％）,对侧颞叶起源1例（5．9％）,不确定起源位置3例（17．6％）。术后随访12～56个月,平均28个月,按Engel分级,Ⅰ级25例,Ⅱ级2例,Ⅲ级2例;失随访2例。结论颞叶占位性病变伴癫痫患者发作间期癫痫样波不仅仅局限于同侧颞叶,发作期脑电与病变有很好的相关性,该类患者应尽早手术切除治疗,可取得很好的疗效。     

颅内电极监测对顽固性颞叶癫痫致痫灶的定位价值

目的:探讨发作期及发作间期颅内电极监测对癫痫灶的定位作用。方法:20例难治性颞叶癫痫,经临床、影像学及头皮脑电图不能确定致痫灶部位,应用立体定向技术,在患者双侧颞叶植入硬膜下条状电极,进行长时间视频脑电图监测,记录发作期和发作间期的脑电图变化,并与头皮脑电图、MRI进行比较,分析癫痫灶部位,进行手术治疗,术后跟踪随访,评估致痫灶定位的准确性。结果:20例癫痫病人颅内电极埋藏时间1～5天,每个患者至少监测到2次临床发作,每一病例均记录发作间期和发作期的异常放电活动。15例发作间期与发作期定侧一致,2例发作间期为双侧棘波病灶,3例发作间期定位与发作期不一致。按Engel术后效果分级:手术效果满意(癫痫发作消失)13例(65%),显著改善3例(15%),良好3例(15%),无效1例(5%)。所有病例均未出现因颅内电极埋藏而致的并发症。结论:对于致痫灶不能定位的难治性癫痫,应用颅内电极记录方法,尤其是发作期起始时脑电图变化,可以确定致痫灶位置,为癫痫手术治疗提供可靠的依据。     

边缘系统癫痫术前致痫灶定位的复杂性（附3例临床报道）

目的 探讨癫痫外科中边缘系统癫痫(LE)术前定位的复杂性以及临床中的相应对策.方法 选择致痫病灶位于边缘系统的局灶性癫痫患者3例,所有患者皆在我研究所实施了局灶性切除手术,术后随访1年以上效果良好.对这3例患者术前各项评估结果,包括发作症状、头皮脑电图(EEG)及MRI进行分析比较.结果 3例患者中,1例患者致痫灶位于右侧海马及海马旁回,但头皮EEG发作期与发作间期异常放电皆出现在对侧.另一例患者致痫灶位于右侧海马旁回后部,靠近穹隆.头皮EEG与发作症状显示患者为双侧独立起源的颞叶癫痫.最后1例致痫灶部位与第2例相似,但症状及头皮发作期EEG显示为额叶起源.结论 LE不论从症状、神经电生理还是在手术决策方面都非常复杂.颞叶内侧型癫痫头皮EEG可出现定位错误;临床表现为双侧颞叶癫痫的致痫灶可能来自位于颞叶后部中线附近的单一致痫灶;LE中致痫灶位于相似部位的患者,可以因致痫灶病理性质不同而表现出非常不同的临床表现.     

颞叶内侧癫痫智力损害与发作间期痫样放电扩散区域的相关性

目的探讨颞叶内侧癫痫患者智力损害与发作间期痫样放电扩散区域的关系。方法纳入颞叶内侧癫痫患者145例,收集一般临床资料,分析智力损害与发作间期痫样放电区域关系。结果 (1)颞叶内侧癫痫患者病程越长、发作频率越高,总体智商、言语智商及操作智商损害越明显;起病年龄越小,总体智商越下降明显。(2)左侧颞叶内侧癫痫患者发作间期痫样电波及左侧中央区、顶区与智商呈负相关;右侧颞叶内侧癫痫患者发作间期痫样电波放电波及右额区与操作智商呈负相关,而波及右枕区则呈正相关。结论 (1)颞叶内侧癫痫患者智力损害与病程及发作频率相关;(2)左侧颞叶内侧癫痫患者发作间期异常放电波及同侧中央、顶区时更容易造成智力损害,而右侧颞叶内侧癫痫患者发作间期痫样电波放电波及右额区时,操作智商损害更明显。     

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。     

局灶颞叶外癫痫间期痫样放电的分布与手术疗效的关系

目的探讨MRI显示为颞叶外局灶病变的癫痫患者发作间期痫样放电的分布与手术疗效的关系。方法回顾性分析106例磁共振显示颞叶外局灶病变的癫痫患者的电生理、影像、手术及术后随访资料。根据发作间期痫样放电的分布将病例分为三组,A组为间期正常范围脑电图,B组为间期痫样放电仅分布于病变所在脑叶,C组为间期痫放电超出病变所在脑叶。结果病变分布包括额叶57例,顶叶29例,枕叶17例,岛叶2例,下丘脑1例。间期痫样放电分布为A组占28.3%(30/106),B组占29.2%(31/106),C组占42.5%(45/106)。手术均行病变切除或立体定向毁损术,术后随访12~52个月,平均28个月,各组按Engel分级,A组:I级23例,Ⅱ级2例,Ⅲ级2例,Ⅳ级2例;B组:I级21例,Ⅱ级3例,Ⅲ级4例,Ⅳ级2例;C组:I级27例,Ⅱ级6例,Ⅲ级3例,Ⅳ级3例,各组间疗效没有统计学差异(P0.05)。结论 MRI显示为局灶颞叶外病变的癫痫患者手术切除或立体定向毁损病变能取得很好的控制疗效,且疗效与发作间期痫样放电的分布无关。     

颅内电极脑电图监测对癫痫致痫灶的定位作用

目的探讨颅内电极脑电图（EEG）监测对癫痫致痫灶的定位作用。方法对经临床、影像学和常规EEG检查不能确定致痫灶部位的20例难治性颞叶癫痫患者，应用立体定向技术，经双侧颞叶植入硬膜下条状电极进行长时间EEG监测，观察发作期及发作间期EEG变化，结合常规EEG、MRI检查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20例患者颅内电极埋藏时间为1—5d，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。20例患者发作期颅内电极EEG均能准确定位，15例致痫灶发作间期与发作期一致，2例发作间期为双侧棘波，3例发作间期定位与发作期不一致。术后按Engel疗效分级：发作消失13例（65％），显著改善3例（15％），良好3例（15％），无效1例（5％）。未出现因颅内电极安置所致的并发症。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。     

药物难治性癫痫MRI表现与脑电图及病理对照研究

目的 探讨药物难治性癫痫发作间期MRI与脑电图(EEG)在致痫灶定位中的相关性以及MRI表现的病理学基础.方法 对40例药物难治性癫痫患者术前行传统MRI及视频EEG检查,并对其中25例颞叶癫痫患者行弥散加权像扫描.手术方式包括标准颞前叶切除术、选择性海马杏仁核切除术及致痫灶切除术等,对切除的脑组织进行病理学检查.结果 33例患者传统MRI检查结果显示的异常包括:海马硬化(16例)、脑发育不良(5例)、颞极蛛网膜囊肿(3例)、颅内肿瘤(3例)、脑软化灶(2例)、脉络膜裂囊肿(2例)、脑软化合并颞极蛛网膜囊肿(1例)和小脑萎缩(1例).发作间期颞叶癫痫患者发作侧海马表观弥散系数(apparent diffusion coefficient,ADC)值[(102.1±4.7)×10-5 cm2/s]较对侧[(84.6±5.9)×10-5 cm2/s]明显升高(t=12.7,P<0.01).所有癫痫患者发作间期EEG均呈异常改变.24例患者传统MRI检查所示病变区与发作间期EEG定位的致痫灶部位一致,4例患者传统MRI检查显示正常而其发作侧海马ADC值却较对侧增高.结论 传统MRI与ADC同时用于评价致痫灶优于任一单独应用者,如结合EEG将更有助于对癫痫的术前评价.     

长程视频脑电结合影像学在海绵状血管瘤伴发癫痫手术评估中的应用

目的探讨长程视频脑电结合影像学在脑海绵状血管瘤(cerebral cavernous malformation, CCM)伴发癫痫手术的评估中的应用方法及意义。方法对74例2015～2020年来我中心就诊的伴发癫痫的CCM患者的临床资料进行回顾性分析,总结CCM伴发癫痫的脑电特征及长程视频脑电(video electroen-cephalogram, VEEG)结合磁共振成像(magnetic resonance imaging, MRI)、发作间期正电子发射计算机断层扫描(positron emission tomography, PET)在评估手术中的具体方法。结果 (1)手术组54例,MRI:显示海绵状血管瘤部位为:颞叶34例、额叶15例、顶叶3例、枕叶1例,多发1例,54例中3例为双重病理(CCM+其他脑叶软化灶2例,左半球多发CCM+右海马硬化1例);VEEG:发作间期或(及)发作期脑电的痫样放电部位,或(及)症状学提示的致痫灶与病灶(CCM)部位一致或同侧为47例,痫样放电出现在CCM对侧、双侧(且病灶对侧相应部位痫样放电数量更多)共6例,其余1例多发CCM为非致痫灶(痫样放电出现在右颞);PET:39例行PET检查;手术:术中运用超声及皮质脑电监测(electrocorticogram, ECoG),其中15例行CCM癫痫病灶+同侧前颞叶海马杏仁核切除,38例行CCM癫痫病灶切除,1例左半球多发CCM行右前颞叶海马杏仁核切除;病理:54例中的53例确定为CCM继发癫痫,1例海马硬化继发癫痫。(2)非手术组20例,为单次发作或服药后发作控制较好,或(及)综合定位信息不明确,建议药物治疗。结论长程视频脑电监测(VEEG)在伴发癫痫的CCM手术评估中具有重要的应用意义,其结合MRI及PET进行综合分析,以达到准确定位致痫灶,明确手术切除范围,从而提高手术治疗效果。     

隐源性癫痫致痫灶最常见好发部位及相关病理特征

目的 回顾性分析隐源性癫痫致痫灶最常见的好发部位及手术切除标本的病理改变,探讨隐源性癫痫致痫灶的发病机制.方法 通过向26例头部CT、MRI等影像学检查无特异性表现的患者颅内可疑脑区植入皮层电极及深部电极,行长程视频脑电监测,记录发作间期及发作期脑电图变化,确定癫痫病灶起始区,手术切除致痫灶并送病理,术后定期随访.结果 26例均可以明确致痫灶,其中癫痫发作单独起源于颞叶新皮层及颞叶内侧的13例,占本组病例的50％;送检标本病理结果显示胶质细胞增生、皮层分层紊乱25例,占本组病例的96.15％,其中伴有海马硬化14例.术后随访1年以上,Engel Ⅰ级15例,Engel Ⅱ级8例,Engel Ⅲ级2例,Engel Ⅳ级1例.无严重并发症及手术死亡病例.结论 颞叶新皮层及颞叶内侧是隐源性癫痫致痫灶最常见的好发部位,皮层发育不良是隐源性癫痫手术切除标本中常见的病理改变,其中海马硬化是颞叶内侧常见的病理改变.颞叶新皮层及颞叶内侧病理改变不仅经常相伴出现,而且病理改变轻微.通过外科干预,效果较满意.按Engel分级,位于颞叶新皮层及颞叶内侧的病例手术疗效较其他好,Engel's分级均在Ⅱ级以上.     

脑磁图累积源成像在药物难治性颞叶癫痫术前评估中的应用

目的 探讨脑磁图累积源成像（MEG）在难治性颞叶癫痫术前评估中的应用价值。方法 回归分析法2006年1月至2018年1月手术治疗的11例难治性颞叶癫痫临床资料。使用MRI、长程视频脑电图、MEG以及颅内电极脑电图（IEEG）帮助定位致痫灶并制定手术方案,术后随访1年,按Engel分级评估疗效。结果 MRI无明显异常5例;异常6例,其中2例与手术侧一致。11例IEEG均有异常,其中9例与手术侧一致。11例MEG均有异常,9例与手术侧一致,主要集中在4~30 Hz;MEG与IEEG一致7例。11例中,9例有效,2例无效;其中Engel分级Ⅰ级6例,Ⅱ级1例,Ⅲ级2例,Ⅳ级2例。结论 MEG分析能为难治性颞叶癫痫术前评估提供重要信息,帮助识别致痫灶和潜在癫痫网络。     

Magnetoencephalography in partial epilepsy: Clinical yield and localization accuracy

The goals of this study were to determine (1) the yield of magnetoencephalography (MEG) according to epilepsy type, (2) if MEG spike sources colocalize with focal epileptogenic pathology, and (3) if MEG can identify the epileptogenic zone when scalp ictal electroencephalogram (EEG) or magnetic resonance imaging (MRI) fail to localize it. Twenty-two patients with mesial temporal (10 patients), neocortical temporal (3 patients), and extratemporal lobe epilepsy (9 patients) were studied. A 37-channel biomagnetometer was used for simultaneously recording MEG with EEG. During the typical 2–3–hour MEG recording session, interictal epileptiform activity was observed in 16 of 22 patients. MEG localization yield was greater in patients with neocortical epilepsy (92%) than in those with mesial temporal lobe epilepsy (50%). In 5 of 6 patients with focal epileptogenic pathology, MEG spike sources were colocalized with the lesions. In 11 of 12 patients with nonlocalizing (ambiguous abnormalities or normal) MRI, MEG spike sources were localized in the region of the epileptogenic zone as ultimately defined by all clinical and EEG information (including intracranial EEG). In conclusion, MEG can reliably localize sources of spike discharges in patients with temporal and extratemporal lobe epilepsy. MEG sometimes provides noninvasive localization data that are not otherwise available with MRI or conventional scalp ictal EEG.     

Ictal magnetoencephalographic study in a patient with ring 20 syndrome

OBJECTIVE: To report the ictal magnetoencephalography (MEG) in a patient with ring chromosome 20 mosaicism, a rare chromosomal anomaly associated with intractable epilepsy. METHODS: MEG and simultaneous EEG were recorded with a 204 channel whole head MEG system. Ten habitual seizures occurred during the acquisition, which was done twice. The equivalent current dipoles (ECDs) for ictal discharges on MEG were calculated using a single dipole model. The ECDs were superimposed on a magnetic resonance image. RESULTS: During the seizures, EEG showed prolonged bursts of 5-6 Hz high voltage slow waves with spike components, dominantly in the bilateral frontal region. MEG showed epileptiform discharges corresponding to the ictal EEG. Ictal discharges on MEG were dominant in the frontal area in the initial portion, and then spread in the bilateral temporal area in the middle of the seizure. ECDs obtained from the spikes of the initial portion were clustered in the medial frontal lobe. CONCLUSIONS: The source of the ictal MEG was localised in the medial frontal lobe. The findings suggest that the mechanism underlying epilepsy in this case might be similar to medial frontal lobe epilepsy. Ictal MEG is a valuable tool for detecting the site of seizure onset.     

Routine EEG and Temporal Lobe Epilepsy: Relation to Long-Term EEG Monitoring, Quantitative MRI, and Operative Outcome

Summary: Purpose: To investigate the relation among routine EEG, long-term EEG monitoring (LTM), quantitative magnetic resonance imaging (MRI), and surgical outcome in temporal lobe epilepsy (TLE).
Methods: We evaluated 159 patients with intractable TLE who underwent an anterior temporal lobectomy between 1988 and 1993. The epileptogenic temporal lobe was determined by ictal LTM. A single awake-sleep outpatient EEG with standard activating procedures was performed before LTM. EEGs were analyzed by a blinded investigator.
Results: MRI scans showed unilateral medial temporal atrophy (109 patients) or symmetrical hippocampal volumes (50 patients). The surgically excised epileptogenic brain tissue revealed mesial temporal sclerosis, gliosis, or no histopathologic alteration. Routine EEG revealed temporal lobe epileptiform discharges in 123 patients. Routine EEG findings correlated with the temporal lobe of seizure origin (p < 0.0001) and the results of MRI volumetric studies (p < 0.0001). Interictal epileptiform discharges were seen only during LTM in 24 patients. Routine EEG was disconcordant with interictal LTM in another 20 patients. MRI-identifed unilateral medial temporal lobe atrophy was a strong predictor of operative success (p < 0.0001). There was no significant relation between the routine EEG findings and operative outcome (p > 0.20).
Conclusions: Results of this study modified our approach in patients with TLE. Interictal epileptiform discharges localized to one temporal lobe on serial routine EEGs or during LTM may be adequate to identify the epileptogenic zone in patients with MRI-identified unilateral medial temporal lobe atrophy.     

Magnetoencephalographic studies of focal epileptic activity in three patients with epilepsy suggestive of Lennox-Gastaut syndrome.

PURPOSE: To determine the electromagnetic sources of localized epileptic activities using magnetoencephalography (MEG) in three adult patients with epilepsy suggestive of Lennox-Gastaut syndrome (LGS).METHODS: MEG and simultaneous electroencephalography (EEG) were recorded from three adult patients using a 204-channel, whole-head MEG system. Equivalent current dipoles (ECDs) were calculated for epileptic spikes on MEG according to the single dipole model.RESULTS: In two patients, MEG showed epileptiform discharges restricted to the unilateral temporal area, corresponding to the EEG spikes. The ECDs calculated from these MEG spikes were clustered in the unilateral temporal lobe. In our third patient, MEG spikes appeared in the right centroparietal area; ECDs were located to the right parietal lobe.CONCLUSIONS: The sources of epileptiform discharges that were detected in a restricted area were localized to specific parts of the brain cortex. Despite certain limitations (small number of patients; atypical late-onset epilepsy in one) our study suggests that MEG may prove to be a useful tool for investigating electromagnetic features of localized epileptic discharges in patients with LGS. Based on these preliminary results, further studies performed in patients with typical LGS features are justified.     

Ictal non-forced grasping behaviour

Our aim was to investigate whether patients with epileptiform foci in the frontal lobe, as revealed by video EEG (VEEG) analysis, exhibit non-forced grasping behaviour and manipulatory movements during seizures. We retrospectively reviewed ictal videotapes of 30 consecutive patients with frontal and 30 with temporal lobe epilepsy undergoing VEEG for the presence and type of grasping and manipulatory movements. Four of the 30 patients with frontal lobe epilepsy (13%) showed unilateral grasping behaviour, three of whom had whole hand prehension (one with manipulation movements as well) and one pinching movements. In all patients, arm abduction and elevation resembling reaching invariably preceded grasping hand movements. The epileptogenic focus was located in the contralateral and ipsilateral frontocentral region in two and one patient, respectively, and in the ipsilateral orbitofrontal region in another. However, none of the patients with temporal lobe epilepsy showed grasping behaviour. Patients with frontal lobe epilepsy may show non-forced grasping with or without manipulatory finger movements as part of ictal phenomena.     

Complementary use of video-electroencephalography and magnetoencephalography in frontal lobe epilepsy

PurposeThe aim of this study was to compare magnetoencephalography (MEG) and video-electroencephalography (VEEG) source localization in frontal lobe epilepsy (FLE) and determine if these methods can be complementary to each other in clinical practice.MethodThirty patients with pharmaco-resistant FLE who underwent epilepsy surgery were retrospectively enrolled. Video EEG was recorded using an IT-med system using 10/20 system. Regional localization of spikes in VEEG was defined as spikes discharged from adjacent electrodes and no further propagation to a large and/or contralateral area. Magnetoencephalography was recorded for the purpose of focus assessment. Magnetoencephalography spikes were detected for dipole localization of the epileptogenic cortex and the epileptogenic area was classified as mono- or multi-focal.ResultsRegional spike discharges were identified in the interictal VEEG of 20 patients and in the ictal VEEG of 17 patients. Thirteen patients had regional spikes in both interictal and ictal VEEG. Mono-focal localization was identified in the MEG of 20 patients. Fourteen of these patients had regional spike discharges in VEEG. In the remaining six patients, sources localization was only identified by MEG and there were no regional spike discharges either interictal or ictal VEEG.ConclusionIn clinical practice, VEEG is the routine procedure in the presurgical evaluation of FLE. However, we found six cases in which VEEG failed to locate the epileptogenic area that was identified by MEG. We therefore propose that combining VEEG and MEG will optimize the noninvasive presurgical evaluation of epileptiform activities in FLE.     

Magnetoencephalography is more successful for screening and localizing frontal lobe epilepsy than electroencephalography

PURPOSE: The diagnosis of frontal lobe epilepsy may be compounded by poor electroclinical localization, due to distributed or rapidly propagating epileptiform activity. This study aimed at developing optimal procedures for localizing interictal epileptiform discharges (IEDs) of patients with localization related epilepsy in the frontal lobe. To this end the localization results obtained for magnetoencephalography (MEG) and electroencephalography (EEG) were compared systematically using automated analysis procedures. METHODS: Simultaneous recording of interictal EEG and MEG was successful for 18 out of the 24 patients studied. Visual inspection of these recordings revealed IEDs with varying morphology and topography. Cluster analysis was used to classify these discharges on the basis of their spatial distribution followed by equivalent dipole analysis of the cluster averages. The locations of the equivalent dipoles were compared with the location of the epileptogenic lesions of the patient or, if these were not visible at MRI with the location of the interictal onset zones identified by subdural electroencephalography. RESULTS: Generally IEDs were more abundantly in MEG than in the EEG recordings. Furthermore, the duration of the MEG spikes, measured from the onset till the spike maximum, was in most patients shorter than the EEG spikes. In most patients, distinct spike subpopulations were found with clearly different topographical field maps. Cluster analysis of MEG spikes followed by dipole localization was successful (n = 14) for twice as many patients as for EEG source analysis (n = 7), indicating that the localizability of interictal MEG is much better than of interictal EEG. CONCLUSIONS: The automated procedures developed in this study provide a fast screening method for identifying the distinct categories of spikes and the brain areas responsible for these spikes. The results show that MEG spike yield and localization is superior compared with EEG. This finding is of importance for the diagnosis and preoperative evaluation of patients with frontal lobe epilepsy.     

Differentiating between benign and less benign: epilepsy surgery in symptomatic frontal lobe epilepsy associated with benign focal epileptiform discharges of childhood

Benign focal epileptiform discharges of childhood are a genetically determined electroencephalographic trait. Assessment of their clinical relevance in children with epilepsy may be difficult if imaging reveals a lesion congruent or incongruous with the focus of the benign focal epileptiform discharges of childhood. This article reports a boy with parietooccipital benign focal epileptiform discharges of childhood in whom videoelectroencephalography and magnetic resonance imaging disclosed symptomatic frontal lobe epilepsy. Surgical removal of a focal cortical dysplasia in the left frontal lobe yielded freedom from seizures and positive behavioral and cognitive development. Nocturnal benign focal epileptiform discharges of childhood persisted until puberty (follow-up, 50 months). Early diagnostic differentiation of idiopathic syndromes such as idiopathic benign focal epilepsy of childhood from symptomatic focal epilepsies with a potentially less benign course is important. In symptomatic frontal lobe epilepsy, epilepsy surgery may yield an excellent outcome despite the presence of concurrent benign focal epileptiform discharges of childhood.     

Functional connectivity evidence of cortico–cortico inhibition in temporal lobe epilepsy

Epileptic seizures can initiate a neural circuit and lead to aberrant neural communication with brain areas outside the epileptogenic region. We focus on interictal activity in focal temporal lobe epilepsy and evaluate functional connectivity (FC) differences that emerge as function of bilateral versus strictly unilateral epileptiform activity. We assess the strength of FC at rest between the ictal and non‐ictal temporal lobes, in addition to whole brain connectivity with the ictal temporal lobe. Results revealed strong connectivity between the temporal lobes for both patient groups, but this did not vary as a function of unilateral versus bilateral interictal status. Both the left and right unilateral temporal lobe groups showed significant anti‐correlated activity in regions outside the epileptogenic temporal lobe, primarily involving the contralateral (non‐ictal/non‐pathologic) hemisphere, with precuneus involvement prominent. The bilateral groups did not show this contralateral anti‐correlated activity. This anti‐correlated connectivity may represent a form of protective and adaptive inhibition, helping to constrain epileptiform activity to the pathologic temporal lobe. The absence of this activity in the bilateral groups may be indicative of flawed inhibitory mechanisms, helping to explain their more widespread epileptiform activity. Our data suggest that the location and build up of epilepsy networks in the brain are not truly random, and are not limited to the formation of strictly epileptogenic networks. Functional networks may develop to take advantage of the regulatory function of structures such as the precuneus to instantiate an anti‐correlated network, generating protective cortico–cortico inhibition for the purpose of limiting seizure spread or epileptogenesis. Hum Brain Mapp 35:353–366, 2014. © 2012 Wiley Periodicals, Inc.