Direct electrical stimulation of the human cortex can produce subjective visual sensations, yet these sensations are unstable. The underlying mechanisms may stem from differences in electrophysiological activity within the distributed network outside the stimulated site. To address this problem, we recruited 69 patients who experienced visual sensations during invasive electrical stimulation while intracranial electroencephalography (iEEG) data were recorded. We found significantly flattened power spectral slopes in distributed regions involving different brain networks and decreased integrated information during elicited visual sensations compared with the non-sensation condition. Further analysis based on minimum information partitions revealed that the reconfigured network interactions primarily involved the inferior frontal cortex, posterior superior temporal sulcus, and temporoparietal junction. The flattened power spectral slope in the inferior frontal gyrus was also correlated with integrated information. Taken together, this study indicates that the altered electrophysiological signatures provide insights into the neural mechanisms underlying subjective visual sensations.

OBJECTIVE:To summarize the clinical features of collagen type IV alpha 1/2 chain (COL4A)1/2-related epilepsy and the seizure outcomes of patients undergoing epilepsy surgery. METHODS:We retrospectively analyzed the clinical, electroencephalography, and neuroimaging data; genetic characteristics; surgical details; and prognosis of 8 patients (4 boys) treated for COL4A1/2-related epilepsy at Tsinghua University Yuquan Hospital. RESULTS:Two of the probands had COL4A1 variants and six had COL4A2 variants. Four of the variants were de novo. Prenatal abnormalities consisted of intrauterine growth retardation and ventriculomegaly. Three patients had a low birth weight, and one had perinatal retinal hemorrhage. The median age of seizure onset was 8 months, with 75% (6/8) experiencing epilepsy before age 1. Status epilepticus occurred in 38% (3/8) of patients. All patients experienced focal seizures, and 50% (4/8) had focal epileptic spasms. Hemiparesis was observed in 88% (7/8) of patients, and all 8 had developmental delays. The median number of anti-seizure drugs was 5, and all patients had drug-resistant epilepsy. Seven patients had seizures localized to one of the posterior quadrants, consistent with the magnetic resonance imaging features of blurring of the gray-white matter junction and positron emission tomography features of metabolic abnormalities. Other neuroimaging features included bilateral mild white matter abnormalities; unilateral porencephaly near the basal ganglia; ventriculomegaly; focal cerebral calcification; contralateral schizencephaly; and contralateral cortical thickening and cerebellar abnormalities. Six patients underwent unilateral posterior quadrant disconnection, five (83%) of whom had no recurrence for at least 11 months and experienced developmental improvement. No surgical complications were reported. Pathological examination revealed malformations of cortical development in all six surgical cases (five with focal cortical dysplasia [FCD] type Ia and one with FCD type II). SIGNIFICANCE:The results of this case series suggest that early surgical intervention in patients with COL4A1/2-related epilepsy with well-defined epileptogenic zones may improve seizure control and developmental outcomes. PLAIN LANGUAGE SUMMARY:In this case series of eight patients, epilepsy related to variants in the collagen type IV alpha 1/2 chain genes was characterized by drug-resistant localized seizures with an early onset, one-sided muscle weakness, and developmental delay. Neuroimaging revealed various brain abnormalities. Structural abnormalities outside the seizure-onset zone did not appear to affect surgical prognosis. Early surgical intervention in patients with well-defined seizure-onset zones improved seizure control and developmental outcomes.

OBJECTIVE:Tuberous sclerosis complex (TSC) causes focal drug-resistant epilepsy. Prediction of which tubers are epileptogenic remains challenging. We used stereoelectroencephalography (SEEG) to investigate epileptogenic zone (EZ) organization in TSC-related epilepsy, focusing on epileptogenicity of different tuber radiological subtypes. METHODS:We retrospectively studied consecutive patients with TSC-related epilepsy explored by SEEG. Presence of "focal EZ" (comprising "focal tuber," "tuber-plus," and "focal nontuber") or "diffuse EZ" was determined. In focal EZ involving tubers, interictal and ictal epileptogenic biomarkers were compared to the radiological appearance of tubers. In addition to four previously described tuber subtypes, we propose a novel subtype: type E (focal cortical depression, hypointense base on T2/fluid-attenuated inversion recovery). RESULTS:Among 63 patients, 55 (87.3%) patients exhibited focal EZ, including focal tuber (n = 32, 50.8%), tuber-plus (n = 11, 17.5%), and focal nontuber (n = 12, 19.0%, of which 7/12 involved focal cortical dysplasia [FCD]). In the 43 of 63 (68.3%) patients with focal EZ involving at least one tuber, epileptogenicity of 265 explored tubers was analyzed with regard to radiological subtypes. Tuber subtypes A and B were most prevalent (186/265, 70.2%) but among the least epileptogenic on SEEG. The highest ictal epileptogenicity was in subtypes D (77.8%) and E (77.5%) compared to type A/B/C (Fisher exact test; all p < .05). Type D/E tubers exhibited higher interictal biomarkers than type A/B/ C (linear mixed model; p < .05). In patients with focal EZ, following surgical intervention, 36 of 55 (65.5%) achieved Engel class I outcomes, with a higher odds ratio of Engel I in the combined group of focal tuber/focal nontuber compared to tuber-plus EZ (p < .05). SIGNIFICANCE:Most TSC-related epilepsy represents focal EZ related to tubers, but focal extratuber EZ can also occur (FCD or hippocampus). Radiologically, calcified tubers (type D) and tubers with focal cortical depression and central hypointensity (type E) exhibit the highest epileptogenicity, similar to FCD type II.

Both the imbalance of neuronal excitation and inhibition, and the network disorganization may lead to hyperactivity in epilepsy. However, the insufficiency of seizure data poses the challenge of elucidating the network mechanisms behind the frequent and recurrent abnormal discharges. Our study of two extensive intracranial EEG datasets revealed that the seizure onset zone exhibits recurrent synchronous activation of interictal events. These synchronized discharges formed repetitive sequential patterns, indicative of a stable and intricate network structure within the seizure onset zone (SOZ). We hypothesized that the frequent replay of interictal sequential activity shapes the structure of the epileptic network, which in turn supports the occurrence of these discharges. The Hopfield-Kuramoto oscillator network model was employed to characterize the formation and evolution of the epileptic network, encoding the interictal sequential patterns into the network structure using the Hebbian rule. This model successfully replicated patient-specific interictal sequential activity. Dynamic change of the network connections was further introduced to build an adaptive Kuramoto model to simulate the interictal to ictal transition. The Kuramoto oscillator network with adaptive connections (KONWAC) model we proposed essentially combines two scales of Hebbian plasticity, shaping both the stereotyped propagation and the ictal transition in epileptic networks through the interplay of regularity and uncertainty in interictal discharges. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was funded by the National Key R&D Program of China(2017YFA0205904). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethics committee/IRB of Yuquan Hospital of Tsinghua University gave ethical approval for this work. All participants, or their legal guardians, provided informed consent to participate in this study. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors.

Background:Posterior cortex epilepsy (PCE) primarily comprises seizures originating from the occipital, parietal, and/or posterior edge of the temporal lobe. Electroclinical dissociation and subtle imaging representation render the diagnosis of PCE challenging. Improved methods for accurately identifying patients with PCE are necessary. Objectives:To develop a novel voxel-based image postprocessing method for better visual identification of the neuroimaging abnormalities associated with PCE. Design:Multicenter, retrospective study. Methods:Clinical and imaging features of 165 patients with PCE were retrospectively reviewed and collected from five epilepsy centers. A total of 37 patients (32.4% female, 20.2 ± 8.9 years old) with magnetic resonance imaging (MRI)-negative PCE were finally included for analysis. Image postprocessing features were calculated over a neighborhood for each voxel in the multimodality data. The postprocessed maps comprised structural deformation, hyperintense signal, and hypometabolism. Five raters from three different centers were blinded to the clinical diagnosis and determined the neuroimaging abnormalities in the postprocessed maps. Results:The average accuracy of correct identification was 55.7% (range from 43.2 to 62.2%) and correct lateralization was 74.1% (range from 64.9 to 81.1%). The Cronbach's alpha was 0.766 for the correct identification and 0.683 for the correct lateralization with similar results of the interclass correlation coefficient, thus indicating reliable agreement between the raters. Conclusion:The image postprocessing method developed in this study can potentially improve the visual detection of MRI-negative PCE. The technique could lead to an increase in the number of patients with PCE who could benefit from the surgery.

Objective:To analyze the characteristics of stereoelectroencephalography (SEEG) in children with drug-resistant epileptic spasms (ES), and to explore the surgical strategy of children with spastic seizure under the guidance of SEEG.Methods:The clinical data of 156 children with ES who were preoperatively evaluated in the Department of Neurosurgery Ward 3, Tsinghua University Yuquan Hospital from January 2014 to December 2021 were retrospectively reviewed.All children were evaluated in the second stage of stereotactic electrode placement after a non-invasive preoperative evaluation.The characteristics of intracranial EEG, surgical strategy and prognosis were analyzed.Results:A total of 19 eligible children were included, involving 13 boys and 6 girls.The age of first onset and surgical age of them ranged 1 month to 4 years, and 2 years to 13 years, respectively.The SEEG was divided into 3 types in children with ES at the onset.Five children were SEEG type A, presenting with the focal seizure discharges at the beginning and a gradual propagation to widespread fast-wave bursts.Ten children were SEEG type B, presenting a focal leading spike followed by diffused fast-wave bursts.Four children were SEEG type C, presenting a diffuse fast wave rhythm onset.Although some electrode discharges appeared slightly " leading", they covered more than one brain region.After focal resection or thermocoagulation, 13/19 patients did not have the onset of seizures, and 5/19 and 8/19 were graded as SEEG type A, and B, respectively.During the intermittent period of SEEG attacks in children with SEEG type A and B, a significant phenomenon of focal epileptic discharge consistent with the onset of the attack was observed, and surgical removal of these areas effectively controlled spastic seizures.Conclusions:Epileptic spasms may be triggered by a focal neocortical discharge.Intracranial EEG showed that the focal seizure onset evolves into spasm or a focal " leading spike" is a good indicator of surgical prognosis.

目的 评估发作间期动脉自旋标记成像(ASL)在药物难治性局灶性癫痫术前评估中的作用.方法 回顾性分析2022年1-9月在清华大学玉泉医院神经外科行术前评估的药物难治性局灶性癫痫患者的临床资料.共纳入29例患者,其中26例为儿童患者.术前根据临床资料、视频脑电图(VEEG)、头颅结构像MRI、正电子发射断层显像(PET)-CT等评估致痫区.所有患者均行发作间期ASL检查,采用视觉阅片对ASL扫描获得的脑血流(CBF)影像进行定性分析,确定是否存在灌注异常及分布模式,分析异常灌注部位与多学科会诊和立体脑电图(SEEG)确认的致痫区的一致性.结果 29例患者中,术前评估28例(97％)致痫区明确,其中25例行手术治疗;1例(3％)不明确,行内科治疗.29例患者中,26例(90％)存在CBF影像异常,其中19例(66％)为局部低灌注,5例(17％)为局部高灌注,2例(7％)为局部低灌注与高灌注共存,3例(10％)无灌注异常区域.23例(79％)ASL结果与术前评估基本一致,2例(7％)部分一致,4例(14％)不一致.4例存在发作间期近持续局灶性癫痫样放电的患者中,3例存在局部高灌注;25例无近持续间期放电的患者中,4例存在局部高灌注,差异有统计学意义(P=0.034).19例CBF影像显示局灶低灌注的患者中,18例与术前评估致痫区基本一致,1例部分一致;7例CBF影像显示存在高灌注的患者中,5例与术前评估的致痫区基本一致,1例部分一致,1例不一致;CBF影像呈低灌注者与术前评估致痫区的一致率与呈高灌注者与术前评估致痫区的一致率比较,差异无统计学意义(P=0.167).行手术治疗的25例患者中,22例(88％)CBF影像显示的灌注异常部位与手术切除或损毁部位一致.所有患者的中位随访时间为10个月(1～12个月),手术治疗的25例中,术后均无癫痫发作.结论 发作间期ASL有助于识别致痫区,在术前评估中具有一定的定位价值.

Objective:To record stereoelectroencephalography (SEEG) data and to induce cortical electrical stimulation in children with tuberous sclerosis complex (TSC), thus exploring the epileptogenicity of different types of cortical tubers.Methods:The SEEG recording and cortical electrical stimulation data of 50 children with TSC who underwent preoperative evaluation for drug-resistant epilepsy at Epilepsy Center, Tsinghua University Yuquan Hospital from November 2016 to September 2022 were retrospectively analyzed, involving 27 boys and 23 girls with the age of (5.5±3.4) years.According to the results of 3.0T magnetic resonance imaging (3T-MRI) and computed tomography(CT), cortical tubers were classified.The incidences of electroclinical seizures, electrical seizures and seizures induced by cortical electrical stimulation in different types of tubers recorded by SEEG were analyzed, and the differences in the proportion of the above seizures among different types of tubers were compared using the Fisher′ s exact test. Results:A total of 303 cortical tubers were explored using SEEG in 50 patients.The tubers were divided into 6 types, including Type A, B, C, D and E, and focal cortical dysplasia like (FCD-like) type, among which Type E was for the first time proposed in the world.Among these explored tubers, 7 tubers had electrical seizures, and 57 tubers had electroclinical seizures.A total of 64 tubers (21.1%) were epileptogenic.The incidence of epileptogenic tubers in Type A-E and FCD-like type were 3.6%, 1.4%, 19.0%, 77.8%, 77.5%, and 90.0%, respectively. Fisher′ s exact test and Bonferroni correction were performed for pairwise comparisons( P<0.003). There was no significant difference in the incidence of epileptogenic tubes among Type A, B and C. There was significant difference in the incidence of epileptogenic tubes between Type A-C with Type D, Type E and FCD-like type, respectively.There was no significant difference in the incidence of epileptogenic tubes between Type D, Type E and FCD-like like.Electrical stimulation-induced seizures occurred in 36 cortical tubers (11.9%). The positive rate of electrical stimulation seizures in Type A-E and FCD-like type were 0.7%, 1.4%, 4.8%, 44.4%, 45.0%, and 70.0%, respectively.There was significant difference in the positive rate of electrical stimulation seizures between Type A-B and Type D, Type E and FCD-like type, respectively, so as that between Type C versus Type E and FCD-like type.No significant difference in the positive rate of electrical stimulation seizures was found between other pairwise comparisons. Conclusions:This study proposed a new classification of cortical tubers in TSC patients, and Type E is proposed for the first time in the world.SEEG records confirmed great differences in epileptogenicity indifferent types of cortical tubers.Type D, Type E and FCD-like type have higher epileptogenicity, which is of great value for the preoperative evaluation of TSC epilepsy surgery and the placement strategy of SEEG electrodes.

BACKGROUND: In patients with surgically amenable focal cortical dysplasia (FCD), subtle neuroimaging representation and the risk of open surgery lead to gaps in surgical treatment and delays in surgery. OBJECTIVE: To construct an integrated platform that can accurately detect FCD and automatically establish trajectory planning for magnetic resonance–guided laser interstitial thermal therapy. METHODS: This multicenter study included retrospective patients to train the automated detection model, prospective patients for model evaluation, and an additional cohort for construction of the automated trajectory planning algorithm. For automated detection, we evaluated the performance and generalization of the conventional neural network in different multicenter cohorts. For automated trajectory planning, feasibility/noninferiority and safety score were calculated to evaluate the clinical value. RESULTS: Of the 260 patients screened for eligibility, 202 were finally included. Eighty-eight patients were selected for conventional neural network training, 88 for generalizability testing, and 26 for the establishment of an automated trajectory planning algorithm. The model trained using preprocessed and multimodal neuroimaging displayed the best performance in diagnosing FCD (figure of merit = 0.827 and accuracy range = 75.0%-91.7% across centers). None of the clinical variables had a significant effect on prediction performance. Moreover, the automated trajectory was feasible and noninferior to the manual trajectory ( χ 2 = 3.540, P = .060) and significantly safer (overall: test statistic = 30.423, P < .001). CONCLUSION: The integrated platform validated based on multicenter, prospective cohorts exhibited advantages of easy implementation, high performance, and generalizability, thereby indicating its potential in the diagnosis and minimally invasive treatment of FCD.

目的 总结起始于运动前区皮层(PMC)癫痫的电临床特征.方法 回顾性分析2014年5月一2021年1月在清华大学玉泉医院行术前评估并经颅内电极脑电图证实起始于运动前区皮层的6例难治性癫痫患者的临床资料,包括症状学、头皮及颅内脑电图、影像学、手术及随访,并将6例患者分成腹侧组、背侧组、内侧面组3组进行比较.结果 腹侧组有3例患者,背侧组有1例患者,内侧面组有2例患者.腹侧组症状较多,包括过度运动、面部强直(撇嘴)、肢体强直、偏转;内侧面组主要为单侧或双侧肢体非对称强直.头皮脑电图主要为前头部(额中央区)放电.3例MRI阴性,3例MRI提示局灶性皮质发育不良.6例患者均行PET-CT检查,2例有代谢减低区.5例患者行致痫区切除,术后病理均为局灶性皮质发育不良(FCD),1例为FCD Ⅰ型,其余均为FCD Ⅱ型.5例手术切除患者术后随访无发作,未手术切除的1例患者先后行热凝和激光治疗,治疗当天发作即消失.结论 运动前区癫痫发作主要为运动症状,越靠近腹侧,症状越复杂,如过度运动、偏转、面肌强直(撇嘴);越近内侧面,症状越简单,以单侧或双侧肢体强直多见.借助于颅内电极,准确定位,局限性皮层切除可以取得较好的预后,另外,对于运动前区沟底FCD,激光等微创技术也有较好的治疗效果.

Intracranial stereoelectroencephalography (SEEG) is broadly used in the presurgical evaluation of intractable epilepsy, due to its high temporal resolution in neural activity recording and high spatial resolution within suspected epileptogenic zones. Neurosurgeons or technicians face the challenge of conducting a workflow of post-processing operations with the multimodal data (e.g., MRI, CT, and EEG) after the implantation surgery, such as brain surface reconstruction, electrode contact localization, and SEEG data analysis. Several software or toolboxes have been developed to take one or more steps in the workflow but without an end-to-end solution. In this study, we introduced BrainQuake, an open-source Python software for the SEEG spatiotemporal analysis, integrating modules and pipelines in surface reconstruction, electrode localization, seizure onset zone (SOZ) prediction based on ictal and interictal SEEG analysis, and final visualizations, each of which is highly automated with a user-friendly graphical user interface (GUI). BrainQuake also supports remote communications with a public server, which is facilitated with automated and standardized preprocessing pipelines, high-performance computing power, and data curation management to provide a time-saving and compatible platform for neurosurgeons and researchers.

Epilepsy presurgical investigation may include focal intracortical single-pulse electrical stimulations with depth electrodes, which induce cortico-cortical evoked potentials at distant sites because of white matter connectivity. Cortico-cortical evoked potentials provide a unique window on functional brain networks because they contain sufficient information to infer dynamical properties of large-scale brain connectivity, such as preferred directionality and propagation latencies. Here, we developed a biologically informed modelling approach to estimate the neural physiological parameters of brain functional networks from the cortico-cortical evoked potentials recorded in a large multicentric database. Specifically, we considered each cortico-cortical evoked potential as the output of a transient stimulus entering the stimulated region, which directly propagated to the recording region. Both regions were modelled as coupled neural mass models, the parameters of which were estimated from the first cortico-cortical evoked potential component, occurring before 80 ms, using dynamic causal modelling and Bayesian model inversion. This methodology was applied to the data of 780 patients with epilepsy from the F-TRACT database, providing a total of 34 354 bipolar stimulations and 774 445 cortico-cortical evoked potentials. The cortical mapping of the local excitatory and inhibitory synaptic time constants and of the axonal conduction delays between cortical regions was obtained at the population level using anatomy-based averaging procedures, based on the Lausanne2008 and the HCP-MMP1 parcellation schemes, containing 130 and 360 parcels, respectively. To rule out brain maturation effects, a separate analysis was performed for older (>15 years) and younger patients (<15 years). In the group of older subjects, we found that the cortico-cortical axonal conduction delays between parcels were globally short (median = 10.2 ms) and only 16% were larger than 20 ms. This was associated to a median velocity of 3.9 m/s. Although a general lengthening of these delays with the distance between the stimulating and recording contacts was observed across the cortex, some regions were less affected by this rule, such as the insula for which almost all efferent and afferent connections were faster than 10 ms. Synaptic time constants were found to be shorter in the sensorimotor, medial occipital and latero-temporal regions, than in other cortical areas. Finally, we found that axonal conduction delays were significantly larger in the group of subjects younger than 15 years, which corroborates that brain maturation increases the speed of brain dynamics. To our knowledge, this study is the first to provide a local estimation of axonal conduction delays and synaptic time constants across the whole human cortex in vivo, based on intracerebral electrophysiological recordings.

背景 癫痫性痉挛(ES)是儿童最常见的发作类型之一.关于ES患儿手术疗效的数据却很少,ES既往被认为术后疗效不佳,此外,关于ES的电临床特征及其对术后疗效的影响尚不清楚.由于痉挛发作症状表现的对称性和癫痫发作起始放电的广泛性,致痫区定位困难,癫痫手术难度大.但最新研究表明,若选择适合手术条件的痉挛发作类型,可以达到和其他局灶性癫痫相似的手术疗效.因此,探讨影响儿童ES手术预后的影响因素,有助于帮助更多的药物难治性痉挛发作患儿达到手术治愈的目的.

背景 眶额皮质(Orbitofrontal cortex,OFC)是大脑皮层中被研究最少的区域之一,而起始于眶额的癫痫发作,特别是起始于眶额不同部位癫痫的电临床特点还不被人们熟悉.其主要原因可能是由于眶额解剖分区的复杂性、病例罕见、头皮电极很难记录到该部位放电而需要进一步颅内电极的植入来明确发作起始.

Epileptic spasm (ES) is one of the most common types of seizures in children. It is primarily characterized by brief axial contractions lasting less than 2 s and recurring in short clusters. It usually occurs in children of 3 to 12 months of age, although it can also occur after the age of 1 year. In general, children with ES develop other symptoms of epilepsy, such as tonic, tonic‐clonic, or focal seizures, after 3 to 5 years of age. ES in children is often damaging and usually results in developmental regression. First‐line treatments for spasm seizures include adrenocorticotropic hormone (ACTH) and vigabatrin. However, many patients fail to respond to these medications, and continued to have spasms associated with progressive neurodevelopmental degeneration. Therefore, it is important to consider whether children with drug resistance meet surgical indications to consider surgical treatment in such conditions. In this study, we reviewed and summarized the importance of preoperative evaluation in order to provide surgical options for treatment of children with ES.

F-TRACT atlas release - December 2021====================================== The F-TRACT atlas is provided as .csv (comma-separated values) files that can be read in any table editor. In addition, we provide a Matlab routine allowing to read the features of the atlas as Matlab variables. The atlas is provided for free use for research use only, with limited accuracy, which hopefully will improve with subsequent releases. Please cite David et al. (2013) Probabilistic functional tractography of the human cortex, NeuroImage, and Trebaul et al. (2018) Probabilistic functional tractography of the human cortex revisited, NeuroImage, Lemarechal et al. (2022) A brain atlas of axonal and synaptic delays based on modelling of cortico-cortical evoked potentials, Brain, when using the F-TRACT atlas. - f-tract_v2112 : Connectivity probability as well as features describing fibers biophysical properties, estimated from CCEP data recorded in 780 patients, in the AAL, AICHA, Brodmann, Freesurfer, Hammers, HCP-MMP1, Lausanne2008 (resolutions 33, 60, 125, 250, 500) and MarsAtlas parcellation schemes. The CCEP features are: peak and onset latency (LatStart), amplitude, duration, integral, velocity estimated from the onset latency and the fibers distance between the parcels and axonal conduction delays. Synaptic excitatory and inhibitory delays are also provided for each parcel. All features have been estimated separately for patients younger than 15 y.o. (group "0-15") and patients older than 15 y.o. (group "15-100"). - Features maps : Images representing the connectivity probability and response features for all the regions in the Lausanne2008-60 parcellation.

Objective:To investigate the application value of surface-based morphometry (SBM) in preoperative evaluation of refractory epilepsy.Methods:Clinical data of 51 patients with refractory epilepsy admitted to Epilepsy Center, Yuquan Hospital, Tsinghua University from November 2013 to July 2018 were retrospectively analyzed. Fifty-one patients underwent resection or radiofrequency thermo-coagulation of epileptogenic zone with the outcome of Engel Ⅰ assessed at over 6 months post operation. The three-dimensional high-resolution MRI T1-weighed imaging data were analyzed to calculate the proportion of positive results by using three characteristic values of cortical surfaces, i. e. gyrification index (GI), sqrt-transformed sulcus depth (SQ) and thickness (TH), which were obtained by SBM post-procession.Results:According to imaging characteristics and the scope of resection or radiofrequency thermocoagulation of epileptogenic zone, 51 cases were divided into four groups as follows: 13 cases as MRI negative (MN) group, 27 as MRI positive region coinciding with surgical site (PCS) group, 4 as MRI positive region including surgical site (PIS) group, and 7 as MRI positive region noncompatible with surgical site (PNS) group. PCS group was further divided into three types: 13 cases as mesial temporal lobe epilepsy (PCS-MTLE), 5 as focal cortical dysplasia (PCS-FCD), and 9 as encephalomalacia or malformations of cortical development (PCS-EMCD). With all three characteristic values, the lesion positive proportion were 3/13, 21/27, 2/4 and 1/7 for MN group, PCS group, PIS group and PNS group respectively and 8/13, 4/5 and 9/9 for the three types of PCS patients respectively. Lesion positive proportion by using GI was 4/4 in PIS group and 22/27 in PCS group, which were higher than those obtained by SQ(2/4 and 18/27)and TH(1/4 and 21/27). Lesion positive proportion obtained by SQ in MN was 5/13 and that obtained by TH in PNS group was 3/7, while those by GI in MN group and in PNS group were 3/13 and 2/7 respectively.Conclusions:The preliminary study suggests that for patients with refractory epilepsy who have distinctive lesions, GI could be used to locate the lesions with a relatively high positive proportion and good display on the margins of lesions. For MRI-negative patients, SQ may be a relatively sensitive target for lesion detection. For patients with incongruent indications from MRI and other clinical measures, TH may be the optimal target for lesion detection.

To investigate surgical prognostic factors in order to establish a surgical plan for children with drug-resistant epileptic spasms. We retrospectively analysed 64 children with drug-resistant spasms who were operated on in Beijing; the electroclinical features, surgical procedures, and surgical outcomes of these children were discussed in detail. We divided the seizure-free patients into several groups according to imaging, aetiology, and application of stereo-electroencephalography in order to investigate the extent of the various influencing factors. Fifty-three (82.8%) patients had favourable outcome, and 11 (17.2%) had unfavourable outcome. Based on the univariate analysis, the factors associated with favourable seizure outcome were interictal high γ frequency (χ 2 = 4.161; p = 0.041), concordance between MRI and interictal epileptic discharges (IEDs) (χ 2 = 6.148; p =0.013), and concordance between PET and IEDs (χ 2 = 4.281; p = 0.039). Concordance between MRI and IEDs (OR = 0.083, 95% CI = 0.014-0.483; p = 0.006) and continuous discharges on electrocorticography (OR = 0.109, 95% CI = 0.019-0.639; p = 0.014) were important factors associated with a favourable surgical outcome. Resective surgery is an effective treatment for drug-resistant ES in children. A deeper understanding of the predictors of seizure outcome is beneficial for establishing a standard, one-stage resection procedure for spasms in order to benefit more patients who have not previously considered surgery. We propose a workflow for presurgical evaluation in children with epileptic spasms.

Objective:To summarize the surgical treatment of tuberous sclerosis with refractory epilepsy in 42 children.Methods:Forty-two children who were clinically and pathologically diagnosed with tuberous sclerosis with refractory epilepsy in Yuquan Hospital from April 2008 to March 2019 were selected. All children underwent magnetic resonance imaging, 41 underwent long time video electroencephalogram (EEG) monitoring, and 30 underwent genetic examination. All children underwent detailed preoperative evaluation, and either direct resection or intracranial electrode thermocoagulation was then selected.Results:Among the 42 children, 31 (73.8%) had Engel grade Ⅰ, 6 (14.3%) had grade Ⅱ, 3 (7.1%) had grade Ⅲ, and 2 (4.8%) had grade Ⅳ. Among the 31 children without seizures, 19 had EEG abnormality, among whom 16 cases had discharge, 3 cases had EEG abnormality in 1 year, but returned to normal after 1 year. The EEG of the other 12 children was normal after operation. One case of generalized seizure was free of seizure in 6 years after surgery.Conclusion:The epileptogenic foci of tuberous sclerosis with refractory epilepsy in children are usually single or have major localized areas. Detailed preoperative evaluation can accurately identify the epileptogenic nodules and help obtain a good surgical effect.

ProposeDirected cortical responses to intracranial electrical stimulation are a good standard for mapping inter-regional direct connectivity. Cortico-cortical evoked potential (CCEP), elicited by single pulse electrical stimulation (SPES), has been widely used to map the normal and abnormal brain effective network. However, automated processing of CCEP datasets and visualization of connectivity results remain challenging for researchers and clinicians. In this study, we develop a Matlab toolbox named MRIES (Mapping the Responses to Intracranial Electrical Stimulation) to automatically process CCEP data and visualize the connectivity results.MethodThe MRIES integrates the processing pipeline of the CCEP datasets and various methods for connectivity calculation based on low- and high-frequency signals with stimulation artifacts removed. The connectivity matrices are saved in different folders for visualization. Different visualization patterns (connectivity matrix, circle map, surface map, and volume map) are also integrated to the graphical user interface (GUI), which makes it easy to intuitively display and compare different connectivity measurements. Furthermore, one sample CCEP data set collected from eight epilepsy patients is used to validate the MRIES toolbox.ResultWe show the GUI and visualization functions of MRIES using one example CCEP data that has been described in a complete tutorial. We applied this toolbox to the sample CCEP data set to investigate the direct connectivity between the medial temporal lobe and the insular cortex. We find bidirectional connectivity between MTL and insular that are consistent with the findings of previous studies.ConclusionMRIES has a friendly GUI and integrates the full processing pipeline of CCEP data and various visualization methods. The MRIES toolbox, tutorial, and example data can be freely downloaded. As an open-source package, MRIES is expected to improve the reproducibility of CCEP findings and facilitate clinical translation.