听神经瘤手术内听道处理及面听神经保护

目的探讨听神经瘤手术内听道内肿瘤的处理方法,并对显微解剖保留面神经的手术经验和技巧进行讨论,以提高肿瘤的全切率和面神经的保留率。方法回顾性分析经枕下乙状窦后-内听道入路显微外科手术治疗的听神经瘤49例,术前行CT内耳道薄层扫描,术中行面神经功能和脑干听觉诱发电位监测。对听神经瘤内听道处理的手术技巧进行分析。结果术中面神经解剖保留43例,面神经解剖保留率为87.8%,出院时功能保留35例(H-B分级,Ⅰ~Ⅱ级)。解剖未能保留6例,其中2例行面神经端-端吻合。肿瘤全切45例,全切除率为91.8%;近全切除4例。术后无死亡病例。结论熟悉内听道内面听神经与肿瘤的病理解剖关系,熟练掌握显微手术技巧并结合术中监测,对肿瘤全切除和面听神经功能保护具有重要的意义。     

经乙状窦后-内听道入路微创手术治疗听神经瘤

目的探讨听神经瘤微创显微手术切除听神经瘤的手术方法和技巧,以提高肿瘤的全切除率和面神经的功能保护率。 方法回顾性分析陆军总医院附属八一脑科医院自2000年1月至2017年12月应用多模态技术辅助经枕下乙状窦后-内听道入路微创手术治疗的887例听神经瘤患者的临床资料。术后3个月常规复查增强MRI明确肿瘤切除程度,评估面神经功能。 结果肿瘤全切841例,全切除率为94.8%。术中面神经解剖保留832例,面神经解剖保留率为93.7%;解剖未能保留的55例,其中16例术中行面神经端-端吻合,另有3例术后行面神经移植。肿瘤切除3个月后复查,面神经功能Ⅰ~Ⅱ级695例(78.4%）,Ⅲ~Ⅳ级176例(19.8%）,Ⅴ级16例(1.8%）。 结论听神经瘤微创显微手术有助于提高肿瘤切除的安全性和手术疗效,熟练掌握显微手术技巧是提高肿瘤全切除、面神经解剖和功能保护率的关键。     

多模态技术在听神经瘤显微外科手术中的应用

目的探讨采用多模态技术辅助经枕下乙状窦后入路切除听神经瘤的临床疗效。方法回顾性纳入2010年9月至2016年9月重庆医科大学附属第一医院神经外科收治的204例听神经瘤患者,其中48例采用多模态技术辅助切除肿瘤（多模态组）,156例采用常规方法切除肿瘤（常规组）。术后1周行头颅增强MRI扫描观察肿瘤切除程度,术后2周依据House—Brackmann（H—B）分级标准评估面神经功能,术后2周内采用美国耳鼻咽喉头颈外科学会听力分级评估听神经功能。对所有患者行门诊随访,术后3个月、6个月及以后每年行头颅增强MRI扫描,术后6个月评估面神经功能。对比分析两组患者的临床特点、疗效和术后并发症。结果两组患者的性别、发病年龄、病程、肿瘤部位、肿瘤直径、面神经功能分级及听力分级的差异均无统计学意义（均P〉0．05）。两组患者肿瘤全切除率间的差异无统计学意义[多模态组为95．8％（46／48）、常规组为92．3％（144／156）,P：0．527];术后2周多模态组面神经功能保留率显著高于常规组[分别为81．3％（39／48）、64．5％（100／155）,P=0．007];两组患者术后听力保留率的差异无统计学意义[多模态组为6．3％（3／48）、常规组为5．8％（9／156）,P=0．901]。多模态组术后并发症的发生率显著低于常规组[分别为29．2％（14／48）、46．4％（72／155）,P=0．034]。201例患者的随访时间为6～80个月,平均（22．3±4．5）个月。头颅增强MRI结果显示两组患者肿瘤均无复发。术后6个月多模态组面神经功能保留率显著高于常规组[分别为85．4％（41／48）、69．3％（106／153）,P=0．009]。结论多模态技术是一种有效辅助切除听神经瘤的手段,与常规方法相比,在患者术后面神经功能保留率和术后并发症发生率方面表现出一定的优势。     

听神经瘤切除面神经保留技术探讨

目的：探讨和分析中，大型听神经瘤手术面神经保留技术，方法：135例听神经瘤病人，采用枕下开颅乙状窦后经内听道人路，显微外切除肿瘤，在面神经监护下，观察肿瘤与面神经的病理解剖关系，术后随访时间4个月至3年，结果，肿瘤全切除125例（93％），近全切4例（2．9％），次全切6例（4．4％），面神经解剖保留122例（90％），13例（9％）解剖未能保留面神经，结论：术中首先识别不与肿瘤粘连的面神经脑干端及内听道端，再从再端沿面神经锐性分离肿瘤，是面神经解保留的技术关键。     

大型听神经瘤手术治疗策略

目的 总结211例大型听神经瘤手术治疗效果,探讨大型听神经瘤手术治疗策略。方法 211例大型听神经瘤采用枕下乙状窦后经内听道入路,在面神经监护下行显微手术切除肿瘤,术后随访时间3个月至5年。结果 肿瘤全切196例(93％);近全切除7例(3.3％);大部切除8例(4％)。面神经解剖保留192例(91％)。结论 大型听神经瘤手术治疗是首选的治疗方法,术中面神经监护对保留面神经完整性非常重要。     

听神经瘤显微外科手术治疗

目的 报告223例中型、大型听神经瘤显微外科手术治疗效果。方法 应用枕下开颅乙状窦后经内听道入路显微外科手术切除肿瘤。结果 肿瘤全切除208例（93％）,近全切除6例（3％）,次全切除9例（4％）。面神经解剖保留201例（90％）,面神经功能H－BⅠ、Ⅱ级118例（53％）;Ⅲ、Ⅳ级90例（41％）;Ⅴ、Ⅵ级14例（6％）。耳蜗神经功能保留率9％。术后长期随访结果显示98％的病人恢复良好,1例生活不有自理,2例（1％）死亡。结论 显微外科手术是治疗大、中型听神经瘤的有效方法,熟悉肿瘤与面神经的病理解剖关系有助于提高手术效果。     

影响听神经鞘瘤术后有效听力的因素分析

目的分析听神经鞘瘤显微术后影响有效听力的因素。方法 47例听神经鞘瘤在术中听力监护下行枕下乙状窦后入路显微切除术。记录肿瘤的大小、术前听力、肿瘤存内听道的充满程度以及肿瘤与听神经的粘连程度。结果肿瘤均全切,听神经解剖保留75．7％,47例病人有效听力保留率为21．2％。肿瘤直径≤15 mm的28例中有效听力保留率为32．2％,肿瘤直径≥16 mm的19例中有效听力保留率为5．3％。在25例病人中,影像资料显示16例内听道被肿瘤完全充满者有效听力保留率为25％,9例内听道部分充满者有效听力保留率为44．4％。28例肿瘤直径≤15 mm的病人中,16例术前听力为Ⅰ级者术后有效听力保留率为37．5％,12例Ⅱ级以上者(包括Ⅱ级)术后有效听力保留率为 25％。肿瘤大小与内听道充满程度可作为术后有效听力独立影响因素(P<0．001,P=0．027)。而术前听力无统计学意义(P=0．233)。结论肿瘤不完全充满内听道以及其直径小于15 mm有利于有效听力保留,良好的术前听力似乎更有利于有效听力保留,但却没有统计学意义。肿瘤与听神经没有完整界面, 这一点会影响术后有效听力的保留。     

听神经瘤手术面神经的保留技术探讨

目的 探讨听神经瘤的显微手术治疗及面神经保留技术。方法 回顾性分析经神经外科手术治疗的31例听神经瘤病人的临床资料,均采用枕下乙状窦后入路,统计面神经保留率,观察术中肿瘤与面神经的关系,总结手术技巧。结果 肿瘤全切除27例（87.1%）,次全切除4例（12.9%）,面神经解剖保留28例（90.3%）,术后随访3～12个月,House Blackmann标准评估面神经功能：Ⅰ～Ⅱ级14例（45.2%）,Ⅲ～Ⅳ级12例（38.7%）,Ⅴ～Ⅵ级5例（16.1%）。结论 听神经瘤手术面神经保留关键在于电生理监测基础上,熟悉肿瘤与面神经的病理解剖关系,手术操作要轻柔,充分利用肿瘤包膜,妥善处理内听道区。     

弥散张量面神经成像技术在大型听神经瘤术中面神经定位的可行性研究

目的：探索术前运用弥散张量成像（ DTI）技术定位大型听神经瘤与面神经相对位置的可行性,为术中保护和术后改善面神经功能提供帮助。方法对23例直径≥3．0 cm的大型听神经瘤病例,术前采用DTI显示肿瘤侧面神经并定位面神经与肿瘤的相对位置关系,在术中通过观察和电生理监测,验证术前面神经影像定位的准确性,并采取措施保护,术后随访面神经功能。结果肿瘤直径3．0～6．0 cm,平均（3．8±0．8）cm;18例（78．3％）面神经可通过DTI显示,其中8例面神经位于肿瘤腹侧中部,6例位于肿瘤腹侧下方,2例位于肿瘤腹侧上方,1例位于肿瘤上极,1例位于肿瘤下极。术前DTI定位与术中定位吻合率为100％。1例直径5．0 cm听神经瘤的面神经仅部分显示,3例术前面瘫者和1例囊性听神经瘤的面神经未显示。肿瘤全切除19例,次全切除4例。术后随访4～28个月,面神经功能HB Ⅰ级10例,HB Ⅱ级13例。结论 DTI面神经成像技术有助于术前定位大型听神经瘤中的面神经位置,提高面神经的解剖和功能保留率,是降低大型听神经瘤手术后面神经功能障碍的有效技术。     

大型听神经瘤的显微外科治疗

目的探讨听神经瘤显微手术方法,提高肿瘤全切除率及面神经解剖和功能保留率。方法回顾我科2003-08～2009—08经枕下乙状窦后入路显微手术切除的41例大型听神经瘤患者的临床资料,结合文献进行总结探讨。2005—04—29后,对27例行术中面神经电生理监测。结果41例病例中镜下肿瘤全切除37例（92％）,次全切除4例（9．8％）。面神经解剖保留36例（87．8％）,5例（13．2％）未能解剖保留面神经。无手术死亡病例,随诊3个月～6年,术后病人均能恢复正常生活,遗留永久性面瘫5例。结论经枕下乙状窦后人路采用显微技术切除大型听神经瘤,能明显提高手术全切率及面神经保存率。     

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.     

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.     

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.     

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.     

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.     

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.