伽玛刀治疗的现状与进展

立体定向放射外科的概念最早由瑞典Leksell教授提出。经过16年的努力、有179个钴源的第一台伽玛刀(γ-刀)终于面世．并在1967年10月对一例颅咽管瘤病人施行了第一例γ-刀手术。1974年、改进后的第二代γ-刀采用201个。钴源、照射后可产生类球形的毁损灶．还可选用多个等中心照射点．并通过更换准直器型号以治疗不同大小     

X-刀新技术在神经外科的应用

立体定向放射外科(stereotactic radiosurgery)是一种微侵袭性的抻经外科(minimally invasive neurosurgery)新技术．在治疗颅内肿瘤、脑血管畸形和功能性疾病中起着重要作用，颇受国内外学的重视；目前．立体定向放射外科在临床应用较多的有γ-刀和等中心直线加速器放射外科(X-刀)；γ-刀在临床应用介绍较多，已得到医疗界的普遍重视．但由于γ-刀价格昂贵．操作复杂．难以在临床普及应     

伽玛刀立体定向放射外科治疗原发性三叉神经痛的疗效观察

目的观察伽玛刀治疗原发性三又神经痛的近期临床疗效。方法应用伽玛刀治疗35例原发性三叉神经痛患者,选择4mm准直器沿患侧三叉神经根走向设置前后2个靶点,取50％等量曲线包绕,边缘剂量35～42Y,靶中心剂量75-90Gy,三又神经受照长度8～10mm,脑干临界剂量〈20Gy。结果35例原发性三叉神经痛患者随访3～30个月,一次性治疗总有效率为94．2％（33／35）,其中治愈20例（57．1％）,疗效显著8例（22．9％）,显效5例（14．3％）,无效2例（5．7％）。2例无效病例1年后行第二次伽玛刀治疗,疼痛完全缓解,二次治疗总有效率为100％。结论伽玛刀治疗ITN安全、有效,可以作为药物难治性三又神经痛的首选治疗方法。     

伽玛刀治疗颅内疾病3094例临床报告

目的：探讨立体定向放射手术伽玛刀(γ-刀）对颅内疾病的疗效。方法：用1．5Tesla磁共振仪和γ-plart计算机联网定位,γ-plan4.0版剂量规划系统作治疗方案设计,剂量规划,并用Leksellγ-刀对3094例不同类型的颅内疾病包括肿瘤、血管畸形及功能性疾病等实施立体定向放射手术．病种达20余种．年龄1．1～86岁,周边剂量9～75Gy．中心剂量18～150Gy,等剂量曲线30％～90％,靶点数1～12个。结果：随访10～47个月,统计结果表明：γ-刀疗效是确切的。脑动静脉畸形,随防一年半以上,完全闭塞率可达44.6％,体积越小．周边照射剂量越大,闭塞率越高。颅内肿瘤的生长控制率,良性肿瘤≥80.0％．恶性肿瘤≥66.7％。功能性疾病的治疗有救率,帕金森病为85．2％,三叉神经痛为76．9％,癫痫是667％。结论：γ-刀立体定向放射手术较常规开颅手术安全,痛苦少,是治疗颅内一些疾病有效的方法。严格掌握治疗指征,精确定位,合理剂量规划．可确保疗效,降低并发症。     

Leksell伽玛刀治疗原发性三叉神经痛46例报告

目的 评估伽玛刀在治疗原发性三叉神经痛中的作用与地位。方法 用1．5Tesla MRI行三堆超薄立体定位快速扫描。对46例原发性三叉神经痛病人行LEKSELL伽玛刀放射手术治疗，4mm准直器，中心刺量70～90Gy。靶点设定为三叉神经感觉根入桥脑处。结果 用标准咨询法对病人进行疗效评估。放射手术治疗前后疼痛按Ⅰ～Ⅳ级评分。Ⅰ级：无痛；Ⅱ级：偶发疼痛。不需用药；Ⅲ级。轻度疼痛。服药能控制；Ⅳ级。疼痛不能用药控制。46例病人中Ⅰ级26例(56．5％)。Ⅱ级9例(19．5％)。Ⅲ级7例(15．2％)。Ⅳ级4例(8．6％)。此外有4例病人疼痛复发。并接受第二次伽玛刀手术治疗。症状完全缓解。3例病人(6．5％)有迟发性的面部感觉丧失。无其他并发症发生。结论 伽玛刀放射外科手术是一种安全有效治疗三叉神经痛的高科技方法。应用性强。我们认为只要诊断成立。就可考虑施行伽玛刀手术治疗。     

三叉神经痛伽玛刀放射外科治疗（附43例分析）

目的：评价伽玛刀（γ－刀）放射外科治疗三叉神经痛（TN）43例治疗结果。方法：采用1．5TD磁共振成像（MRI）、GammaPlan治疗计划系统,Leksellγ－刀治疗34例非肿瘤性TN,治疗靶点在三叉神经感觉根桥脑进入区,单个4mm准直器,最大剂量72－90Gy,50％等计量线限定靶点;9例颅底肿瘤的症状性三叉神经痛边缘剂量12－15Gy。结果：随访3－28个月,平均随访期14．8个月,疼痛100％缓解占69．8％,疼痛缓解＞80％占18．6％,疼痛缓解＞50％占46％,总有效率93％,非肿瘤性TN总有效率90l％。缓解疼痛＜50％3例（7．0％）。3例疼痛缓解后分别在5、9和17个月复发。无效和复发病人经再次治疗后疼痛有效缓解。全组病人无任何并发症,无死亡。结论：γ－刀是治疗三叉神经痛安全和有效的治疗方法。     

旋转式伽玛刀治疗15例原发性三叉神经痛的疗效观察

目的 观察旋转式伽玛刀治疗原发性三叉神经痛的疗效。方法 采用Leksell G型立体定向仪，SIEMENS 1．5T MRI定位，Gamma-TPS2.1规划系统，国产OUR－RGS／A型旋转式伽玛刀治疗15例原发性三叉神经痛患者。定位靶点为三叉神经感觉根，用4mm准直器，1－2个等中心治疗，中心剂量70－90Gy。结果 出现明显疼痛缓解平均为术后2个月，疼痛缓解程度超过90％的9例（60％），疼痛缓解在50％－90％的4例（26．6％），1例稍见好转（6．7％），1例无效（6．7％），有效病例随访5－14个月未见复发，全辣病人均未出现其它阀发症。结论 应用旋转式伽玛刀治疗原发性三叉神经痛安全，有效。     

立体定向伽玛刀治疗脑动静脉畸型研究

目的评估伽玛刀(γ-刀)立体定向放射手术治疗脑动静脉畸形(AVM)的疗效;探讨脑AVM的γ-刀治疗定位方法。方法用立体定向Leksellγ-刀放射外科治疗系统对216例脑AVM进行γ-刀立体定向放射手术,并随访17～31个月。男性患者162例,女性54例,年龄1.5～83岁(Md=26),Spetzler Martin分级:I级42例,Ⅱ级68例,Ⅲ级95例,Ⅳ级7例及Ⅴ级4例。AVM体积0.3～43.9cm3(Md=7.1),放射手术周边剂量12～30Gy,平均(21.2±6.4)Gy。用1.5Tesla磁共振行磁共振血管造影(MRA)定位156例,数字减影血管造影(DSA)定位22例,MRA与DSA联合定位38例。结果γ-刀治疗后的AVM闭塞情况和并发症的发生与其体积、分级、定位方法、周边剂量、剂量规划及质量控制等因素有关。对体积≤5.0cm3或Spetzler Martin分级<Ⅲ级及周边剂量≥20Gy者,其2年闭塞率超过78.5%。本组有4例γ-刀放射手术后出血,9例并发有明显症状的放射性脑水肿。结论γ-刀高科技手术是治疗脑AVM的一种安全、有效的方法,特别是Spetzler MartinI-Ⅱ级或体积≤5.0cm3的AVM及周边剂量≥20Gy者疗效较好;DSA结合MRA联合定位对提高AVM的闭塞率、降低并发症有帮助。     

伽玛刀动物实验定位架的设计制作

放射外科临床应用的立体定位头架不能直接用于动物做放射外科实验。为了完成《伽玛刀对正常神经系统和脑肿瘤的放射生物效应的研究》,我们设计了一种动物定位架,结构合理,使用简便,现介绍如下。 1 原理与结构特点 做伽玛刀(γ-刀)放射外科治疗,必须应用Leksell定位框架,该框架配用于影像技术,如磁共振成像(MRI)、计算机体层摄影(CT),并确保头部处于准直器头盔内的确切位置,以便     

大鼠正常脑组织伽玛刀照射后VEGF表达的实验研究

目的研究伽玛刀(γ-刀)立体定向放射外科照射大鼠正常脑组织后亚急性期血管内皮细胞生长因子(VEGF)随时间变化的表达,探讨VEGF与放射损伤的关系。方法30只Wistar大鼠,随机分为6组,每组5只。其中1组为假照射组,其余5组行γ-刀照射。运用Leksell23004B型γ-刀4 mm准直器以50Gy照射大鼠右侧尾壳核。不同组别的大鼠分别在照射后1、2、4、8、12周深度麻醉下断头取出脑组织,行免疫组织化学染色观察VEGF的表达。结果假照射组及照射后1、2周靶区内无VEGF阳性细胞：照射后4周靶区发现有少数细胞呈弱阳性表达；照射后8周时可见照射侧VEGF阳性细胞数目增加；照射后12周可见VEGF阳性细胞进一步增多。结论γ-刀放射外科以50Gy照射大鼠单侧尾壳核后,照射靶区VEGF出现阳性表达,并且随时间延长呈增高趋势。     

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.     

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.     

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.     

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.     

Neonatal Seizures: Problems in Diagnosis and Classification

Summary: The clinical identification of neonatal seizures is critical for the recognition of brain dysfunction; however, diagnosis is often difficult because of the poorly organized and varied nature of these behaviors. Current classification systems are limited in their ability to communicate motor, autonomic, and electroencephalo-graphic features of seizures precisely and to provide a basis for uniform effective diagnosis, therapy, and determination of prognosis. Recent investigations of neonates, utilizing bedside electroencephalographic/polygraphic/ video monitoring techniques, have provided the basis for improved diagnosis and classification of seizures in the newborn. These studies have demonstrated that not all clinical phenomena currently considered to be seizures require electrocortical epileptiform activity for their initiation or elaboration. In addition, the specific clinical character of the phenomena considered to be seizures, the clinical state of the infant, and the character of the EEG indicate the probable pathophysiological mechanisms involved and suggest probable etiologies, prognosis, and therapy. Similarities between animal models that demonstrate reflex physiology and neonates with motor automatisms and tonic posturing suggest that these clinical behaviors may not be epileptic in origin but, rather, primitive movements of progression and posture mediated by brainstem mechanisms. Although not all clinical behaviors currently considered to be neonatal seizures may have similar pathophysiological mechanisms, they are clinically significant because they all indicate brain dysfunction.     

Valproate Monotherapy in the Management of Generalized and Partial Seizures

Summary: For decades, therapeutic tradition has promoted the concept of polypharmacy in the management of epilepsy. In recent years, however, studies have shown that, for most patients, monotherapy can provide comparable or better seizure control than administration of multiple anticonvulsants, while diminishing the potential for adverse reactions, drug interactions, and poor compliance. Valproate is an important monotherapeutic agent that is highly effective in the control of idiopathic primary and secondarily generalized epilepsies, and partial seizures that do not generalize. Comparative studies have found that valproate is at least as effective as phenytoin and carbamazepine in the treatment of generalized and partial seizures. Given the similar efficacy, other factors such as pharmacokinetics and side effects may therefore determine anticonvulsant selection for monotherapy.     

Un nouveau cadre conceptuel de travail pour la psychiatrie

In an attempt to place psychiatric thinking and the training of future psychiatrists more centrally into the context of modern biology, the author outlines the beginnings of a new intellectual framework for psychiatry that derives from current biological thinking about the relationship of mind to brain. The purpose of this framework is twofold. First, it is designed to emphasize that the professional requirements for future psychiatrists will demand a greater knowledge of the structure and functioning of the brain than is currently available in most training programs. Second, it is designed to illustrate that the unique domain which psychiatry occupies within academic medicine, the analysis of the interaction between social and biological determinants of behavior, can best be studied by also having a full understanding of the biological components of behavior.