脑磁图和脑电图在癫痫诊治中的应用

目的:观察脑磁图、脑电图和磁共振检查在癫痫诊治中的应用,探讨脑磁图和脑电图的相关性。方法:选择38例经临床诊断的癫痫患者,已进行磁共振检查,并经脑磁图和脑电图发现异常放电。观察三种检查方法的定位符合率,比较影像检查与电生理检查的关系。结果:MEG与EEG定位完全一致的有18例(47．4％),定位基本一致(致少有1个叶定位一致)的有8例(21．1％)。EEG发现双侧放电的13例中,5例与MEG定位基本一致,而EEG单侧局灶放电的25例中,20例与MEG基本一致,EEG与MEG定位符合率在单侧局灶放电患者中高(P＜0．05)。MRI发现结构异常15例,与MEG和EEG定位均一致的有6例。结论:脑磁图和脑电图定位符合率约为68．5％。在单侧局灶放电中, MEG与EEG相结合可使致痫灶定位更加准确。     

脑磁图在神经外科中的应用

目的 探讨脑磁图（MEG）在癫痫外科中的定位价值。方法 本组26例癫痫患，男18例，女8例，术前均行脑电图（EEG）检查和影像学检查，同时做了脑磁图（MEG）检查。所有患手术均在MEG指导下进行，术中加用皮层脑电图（ECoG)监测。结果 26例患均能通过MEG进行术前致痫灶与功能定位，其阳性率明显高于EEG和影像学检查。术后复查EEG，22例患较好。短期随访1－3个月，25例患癫痫发作完全消失。结论 MEG是一项术前痫灶定位和功能保护的有效检查方法。     

脑磁图与神经导航结合在癫痫外科的应用

目的探讨脑磁图定位和神经导航方法二者结合在癫痫外科的应用价值。方法选择12例顽固性癫痫手术,术前脑磁图确定皮质癫痫灶及中央后回感觉皮质范围,然后与神经外科导航系统结合应用于手术当中。结果脑磁图癫痫灶定位与术中皮质脑电图定位符合率100％。按Engel分级作为癫痫疗效标准,术后癫痫发作完全停止9例(1级),发作减少90％以上2例(2或3级),发作减少不到90％1例(4级)。无一例出现手术后神经功能障碍。结论脑磁图是无创确定癫痫灶和功能区皮质空间位置关系的重要工具,脑磁图定位结合神经导航方法的应用可使癫痫外科手术更精确,侵袭更小。     

南京脑科医院脑磁图中心 脑磁图简介

脑磁图（MEG）是一种通过测量脑磁场信号，进行癫痫病灶和脑功能区定位的新技术，对人体无侵袭、无损害，具有极高的敏感性和时间．空间分辨率。MEG可对脑磁信号及其发生源进行精确测定和定位．并通过影像融合技术叠加于MRI影像上，即磁源性影像（MSI），实现了大脑功能和解剖的统一。我院引进的是加拿大VSM公司最新型CTF-275信道全头型脑磁图系统，是目前华东地区唯一一台脑磁图，开展包括癫痫病灶的定位，脑功能区定位（视觉、听觉、运动、体感、语言认知）等项目，作为评估和指导癫痫手术的重要手段；神经外科手术前功能区的定位，     

脑磁图对有颅内肿瘤的癫痫病人局部致痫灶的定位价值

目的研究脑磁图（magnetoencephlography,MEG）在颅内肿瘤的癫痫病人中致痫灶的定位价值.方法选择经手术、病理证实的颅内肿瘤25例,术前通过148信道MEG系统记录和分析自发脑磁活动.结果本组25例患者中有21例术前致癫灶MEG定位结果与术中ECoG证明的一致,两者符合率达84%.术后随访3～37个月,平均17个月.手术总有效率达96%.25例患者中19例肿瘤的位置和癫痫灶的位置一致,致癫灶位于肿瘤边缘者10例;距肿瘤约2cm者9例;远隔部位异常者4例;MEG检查没有阳性发现者2例.结论MEG对于预测颅内肿瘤的致痫灶是一种有用的方法,它有助于制定切除病变并同时处理癫痫外科的手术计划.     

顽固性癫痫患者术前MEG、V-EEG、MRI与术中ECoG的对比

目的　探讨脑磁图 (magnetoencephalography ,MEG)对顽固性癫痫患者致痫灶定位的可行性及临床应用价值。方法　本组 6 3例患者中 ,男 4 4例 ,女 19例 ,年龄 5～ 5 2岁 (平均 2 2 .9岁 ) ,病程 1～ 2 0年 (平均 7.7年 )。所有患者术前均行MEG检查 ,同时还行了视频脑电图 (V EEG)和磁共振成像 (MRI)检查 ,将它们的检查结果与术中皮质脑电图 (ECoG)监测进行对比。结果　术前MEG、V EEG和MRI检查的阳性率分别为 81.0 % (5 1/ 6 3)、85 .7% (5 4 / 6 3)和 88.9% (5 6 / 6 3) ,三者比较差异性不显著 (P >0 .0 5 )。而术前MEG、V EEG和MRI检查与术中ECoG监测结果的符合率分别为 90 .2 % (46 / 5 1)、74 .1% (40 / 5 4 )和 76 .8% (43/ 5 6 ) ,MEG的符合率与V EEG、MRI相比较有极显著性差异 (P <0 .0 1)。MEG、V EEG和MRI三项检查的结果结合起来与术中ECoG监测结果总的符合率为 96 .8% (6 1/ 6 3)。结论　MEG是一种无创性术前致痫灶定位技术 ,其与术中ECoG检测的符合率明显高于V EEG和MRI。MEG联合V EEG和MRI等多种术前检查技术 ,可进一步提高顽固性癫痫患者的致痫灶的定位准确性     

南京脑科医院脑磁图中心脑磁图简介

正脑磁图(MEG)是一种通过测量脑磁场信号,进行癫痫病灶和脑功能区定位的新技术,对人体无侵袭,无损害,具有极高的敏感性和时间,空间分辨率。MEG可对脑磁信号及其发生源进行精确测定和定位,并通过影像融合技术叠加于MRI影像上,即磁源性影像(MSI),实现了大脑功能和解剖的统一。我院引进的是加拿大VSM公司最新型CTF-275信道全头型脑磁图系统,是目前华东地区唯一一台脑磁图,开展包括癫痫病灶的定位,脑功能区     

南京脑科医院引进脑磁图机

脑磁图（magnetcencephalogragpgy,MEG）是一种通过测量脑磁场信号，对癫痫病灶和脑功能区进行定位及评价其状态的设备，是目前直接测量大脑功能活动的最新技术，可对脑磁信号及其发生源进行精确测定和定位，并通过影像融合技术叠加于MRI影像上，即磁源性影像（magnetic source imaging ,MSI），实现了功能影像和解剖影像的统一。     

脑磁图对颞叶以外癫痫颅内电极置入的指导价值

目的研究在颞叶以外癫痫的诊疗中,脑磁图对颅内电极置入方案的指导价值。方法自2011年3月至2013年9月,对将行颅内电极置入的顽固性癫痫患者评估,先在电-临床症状学、影像学、脑电图等结果的基础上设计出初步的颅内电极埋置方案,然后添加MEG定位信息,并根据MEG调整电极埋置方案,得出最终颅内电极置入计划。继而行颅内脑电图监测并行手术治疗。最后分析颞叶以外癫痫中,脑磁图对颅内电极置入方案的指导价值。结果成功定位癫痫发作起始区并完成手术治疗、且经颅内电极证实为颞叶以外癫痫（NTLE）者有22例。9例（40.1%）患者MEG对iEEG电极置入方案产生额外于其它常规评估手段的指导作用（因MEG而增加电极覆盖）,其中7例（31.8%）经iEEG证实这些增加的定位信息与发作起始区一致。术后平均随访33.3个月：EngelⅠ级14例（63.6%）,EngelⅡ级3例（13.6%）,EngelⅢ级3例（13.6%）,EngelⅣ级2例（9.1%）。结论区别于视频脑电图、MRI等其它的无创检查,MEG能够对有创的iEEG电极埋置方案起到额外指导作用,能使电极埋置更合理精确、有针对性,并可能提高癫痫手术的疗效。     

磁共振阴性的局灶性脑皮质发育不良的手术治疗

目的探讨磁共振难以确定病灶的致痫性局灶性脑皮质发育不良的诊断和定位方法,提高手术治疗效果。方法回顾性分析联合应用视频脑电图(VEEG)、脑磁图(MEG)及术中皮层电极脑电图监测(ECo G)检查,诊断、定位并经手术后病理证实为局灶性皮质发育不良(FCD)的24例磁共振检查阴性的难治性癫痫患者的临床资料。结果 24例癫痫患者行手术治疗,病理FCDⅠa型5例,FCDⅠb型3例,FCDⅠc型5例,FCDⅡa型6例,FCDⅡb型5例。术后随访1~5年,EngelⅠ级9例,EngelⅡ级5例,EngelⅢ级8例,EngelⅣ级2例。结论联合应用VEEG、MEG和(或)ECo G技术有助于准确诊断和定位磁共振阴性的FCD,提高FCD致难治性癫痫的手术疗效。     

Diagnostic Difficulties and Treatment Implications

Summary: Differentiation between types of epileptic seizures has been aided in recent years by the introduction of intensive neurodiagnostic techniques and the development of increasingly detailed classification systems. Paradoxically, these developments have not simplified the task of matching the appropriate antiepileptic drug to a particular seizure type. It is reasonable to assume that anticonvulsant drugs will have different effects on different types of seizures, but faulty, circular reasoning can enter the picture if one also assumes that responses of seizures to different drugs signify different seizure types. There are several examples of differential diagnoses that can fall prey to this problem, including the diagnosis between partial seizures with secondary generalization and generalized tonic-clonic seizures, and the diagnosis between complex partial seizures and absence seizures with automatisms, among others. Considerations of etiology in future classification systems can further complicate the problem: should one then choose an anticonvulsant drug on the basis of individual seizure type or on the basis of the type of epilepsy? Ramifications of this issue extend even to the drug approval process. Official sanction is not given for use of a drug for a seizure type not included in the original efficacy studies, even if later scientific evidence shows that seizure type to be related to a type that is included. New trials must be undertaken. These problems arise from how we choose to classify seizures.     

Cognitive Dysfunction Associated with Antiepileptic Drug Therapy

Summary: Epilepsy is frequently associated with cognitive dysfunction. However, the reasons for this correlation are unclear. Possible influential factors include patient age; duration, frequency, etiology, and type of seizures; hereditary factors; psychosocial issues; and antiepileptic drug (AED) therapy. Whereas many of these factors are beyond the physician's control, AED therapy is one element that can be addressed in treatment decisions by recognizing the potential cognitive effects of particular AEDs. For example, phenobarbital impairs memory and concentration; phenytoin affects attention, problem solving ability, and performance of visuomotor tasks. In contrast, carbamazepine may affect concentration, while valproate would appear to have minimal effects on cognition. Moreover, cognitive effects of AEDs are amplified with coadministration of multiple anticonvulsants (polytherapy). A review of studies on the cognitive effects of monotherapy with AEDs, as opposed to those of polytherapy, provides evidence that drug-related cognitive dysfunction can be reversed if patients are switched to a simpler therapeutic regimen. Future research should be directed toward developing reliable measures for assessing and monitoring cognition, and understanding the particular cognitive side effects of each AED. Physicians also need to revise their opinions about which side effects are "tolerable" for epileptic patients.     

Hepatic Considerations in the Use of Antiepileptic Drugs

Summary: Virtually all of the major antiepileptic drugs (AEDs) can cause hepatotoxicity, although fatal hepatic reactions are rare. The mechanisms, incidences, and risk profiles for such reactions differ from drug to drug. With carbamazepine and phenytoin, hepatotoxicity may be due to drug hypersensitivity. Although the profiles of patients at risk have not been well-defined for these two antiepileptic drugs, it would appear from reports in the literature that older adolescents and adults are at higher risk than children of developing serious or fatal hepatotoxicity. Once hepatotoxicity develops, mortality rates are 10–38% with phenytoin and 25% for carbamazepine. The risk profile for valproate fatal hepatotoxicity has been more clearly defined. Those at primary risk of fatal hepatic dysfunction are children under the age of 2 years who are receiving multiple anticonvulsants and also have significant medical problems in addition to severe epilepsy. The risk is considerably lower for patients over the age of 2 years on valproate monotherapy. In contrast to the risk profile with other AEDs, adults receiving valproate as monotherapy have the lowest risk of hepatotoxicity. Fatal hepatic dysfunction coincident with valproate may be the result of aberrant drug metabolism. Concomitant use of AEDs that induce microsomal P450 enzymes (e.g., phenytoin and phenobarbital) may enhance the production of a toxic metabolite, and hence the greater risk of hepatotoxicity with polypharmacy.     

Vascular Malformations and Epilepsy: Clinical Considerations and Basic Mechanisms

Summary: Vascular malformations (VMs) are associated with epilepsy. The natural history of the various VMs, clinical presentation, and tendency to provoke epilepsy determine treatment strategies. Investigations have probed the mechanisms of epileptogenesis associated with these lesions. Electrophysiologic changes are associated with epileptogenic cortex adjacent to VMs. Putative pathophysiologic mechanisms of epileptogenesis include neuronal cell loss, glial proliferation and abnormal glial physiology, altered neurotransmitter levels, free radical formation, and aberrant second messenger physiology.     

Carbamazepine Efficacy in Adults With Partial and Generalized Tonic-Clonic Seizures

Summary: Carbamazepine and phenytoin are drugs of choice in initial monotherapy for adult partial and secondarily generalized tonic-clonic seizures. These designations reflect the results of the Veterans Administration Epilepsy Cooperative Study Group of 1985. An earlier comparative study of carbamazepine and phenytoin by Ramsay and associates found both drugs equally effective in controlling new-onset seizures. Among the advantages of carbamazepine is that it causes relatively few cognitive and dysmorphic side effects. Its disadvantages are its unavailability in parenteral formulation and its metabolic autoinduction. The latter must be compensated for by planned dosage increases to maintain therapeutic plasma steady-state levels during the first 2 or 3 months of treatment. Carbamazepine is judged a drug of choice in the treatment of these secondarily generalized tonic-clonic seizures, and the drug of choice in children, adolescents, and women susceptible to the dysmorphic side effects associated with other anticonvulsant agents.     

Etiologic and Preventive Aspects of Epilepsy in the Child–Bridging the Gap Between Laboratory and Clinic

Summary: Four broad categories of basic phenomena are pertinent to developing ways to prevent epilepsy. These include mechanisms of epileptogenesis, ictal initiation and temporary entrainment by the seizure discharge of normally functioning brain, seizure propagation, and control mechanisms that function both to restrain the cascade of epileptic events culminating in a seizure and to arrest the epileptic event and restore the interictal state. In newborns and children, hypoxia-ischemia is a major factor leading to epileptogenesis, and several schemes are proposed to classify, quantify, and prevent hypoxic-ischemic encephalopathy. Control mechanisms must be better understood in order to develop prophylactic recommendations for epilepsy, and an experimental model of "kindling antagonism" may increase our understanding of these. Programs of prevention of seizures in children will evolve only if basic researchers and clinicians work productively together to develop an adequate understanding of factors important in epileptogenesis and antiepileptogenic control mechanisms.     

Epilepsy and anomalies of neuronal migration: MRI and clinical aspects

Neuronal migration disorders are the result of disturbed brain development. In such disorders, neurons are abnormally located. In diagnosing these conditions, magnetic resonance imaging is superior to any other imaging technique. This enables us to improve our knowledge of the clinical correlates of neuronal migration. With reference to migrational disorder, a retrospective study of all 303 patients with epileptic seizures referred for magnetic resonance imaging during a 3-year period was performed, 13 patients (aged 12-41, mean age 27) were identified. They represent 4.3% of the entire study group. Of the patients with known epilepsy, 6.7% and of the mentally retarded, 13.7% had migrational disorders. Four patients had schizencephaly as the dominant finding, one was classified as hemimegalencephaly, 2 had isolated heterotopias, and 6 had localized pachy- and/or poly-microgyria. The clinical pictures are complex. Ectopias of grey matter are recognised foci of epilepsy, but from an epileptological and a clinical viewpoint little attention has been given to these disorders. The present study shows that malmigration is not rare in epilepsy patients, especially not in the mentally retarded.     

Carbamazepine Efficacy and Utilization in Children

Summary: Carbamazepine is effective for preventing partial and generalized tonic-clonic seizures in children. Although absence epilepsies are more common in children than adults, an estimated 80% of children with epilepsy have seizure types or epilepsies that are potentially responsive to carbamazepine. The differential diagnosis of ictal staring is an especially important issue in children because absence and atypical absence seizures are more prevalent in children than adults. Age-related pharmacokinetic differences and drug interactions are major considerations in children. On average, children have higher clearance rates of carbamazepine, shorter half-lives, and higher ratios of carbamazepine-10, 11-epoxide to carbamazepine than adults. In addition, children with severe epilepsy are more likely to require multiple-drug therapy, which can lead to complex drug interactions. When carbamazepine is administered along with valproate, drug protein binding interactions can cause intermittent side effects.     

Predisposing and Causative Factors in Childhood Epilepsy

Summary: We review information from large studies of defined populations, examining the role of known factors and especially of prenatal and perinatal factors in contributing to nonfebrile seizure disorders of early childhood. We depend especially, but not exclusively, on the recently completed analyses from the Collaborative Perinatal Project of the National Institute of Neurological and Communicative Disorders and Stroke, the NCPP. About 4% of children in the NCPP who had at least one non-febrile nonsymptomatic seizure by the age of 7 years had a previous seizure during acute neurologic illness, such as meningitis or during the acute illness after trauma. Many such seizures should potentially be preventable. Of children with seizures, 10% had had a neonatal seizure and 13% had had a febrile seizure. Among the hundreds of prenatal and perinatal factors explored as predictors of childhood seizure disorders, the principal predictors identified were congenital malformations of the fetus, cerebral and noncerebral; family history of certain neurologic disorders; and neonatal seizures. In agreement with the British National Child Development Study, labor and delivery factors in the NCPP appeared to contribute very little to childhood seizure disorders. Maldevelopment, rather than damage at birth to an initially intact nervous system, appeared to be the more common mechanism. Most seizure disorders of early childhood remained unexplained by the large set of prenatal and perinatal characteristics examined.     

Classification of methods in transcranial Electrical Stimulation (tES) and evolving strategy from historical approaches to contemporary innovations

Transcranial Electrical Stimulation (tES) encompasses all methods of non-invasive current application to the brain used in research and clinical practice. We present the first comprehensive and technical review, explaining the evolution of tES in both terminology and dosage over the past 100 years of research to present day. Current transcranial Pulsed Current Stimulation (tPCS) approaches such as Cranial Electrotherapy Stimulation (CES) descended from Electrosleep (ES) through Cranial Electro-stimulation Therapy (CET), Transcerebral Electrotherapy (TCET), and NeuroElectric Therapy (NET) while others like Transcutaneous Cranial Electrical Stimulation (TCES) descended from Electroanesthesia (EA) through Limoge, and Interferential Stimulation. Prior to a contemporary resurgence in interest, variations of transcranial Direct Current Stimulation were explored intermittently, including Polarizing current, Galvanic Vestibular Stimulation (GVS), and Transcranial Micropolarization. The development of these approaches alongside Electroconvulsive Therapy (ECT) and pharmacological developments are considered. Both the roots and unique features of contemporary approaches such as transcranial Alternating Current Stimulation (tACS) and transcranial Random Noise Stimulation (tRNS) are discussed. Trends and incremental developments in electrode montage and waveform spanning decades are presented leading to the present day. Commercial devices, seminal conferences, and regulatory decisions are noted. We conclude with six rules on how increasing medical and technological sophistication may now be leveraged for broader success and adoption of tES.