脑干听觉诱发电位在老年人椎基底动脉供血不足的诊断价值

目的 探讨脑干听觉诱发电位(BAEP)测定对诊断老年人椎基底动脉供血不足(VBI)的临床价值.方法 选择符合可临床确诊为VBI的60例老年患者为病例组,在眩晕症状发作期进行BAEP测定.并选择60例老年体检者为对照组.结果 病例组60例中有26例(43.3%)BAEP测定异常,BAEP测定异常病例中内耳型异常有10例(38.5%),8例表现为波I PL延长,2例表现为波I PL的ILD>0.4ms.脑干型异常16例(61.5%),10例表现为Ⅰ～Ⅲ IPL延长,2例为Ⅲ一Ⅴ的IPL延长和2例为Ⅰ-Ⅴ IPL的ILD>0.4ms等.对照组BAEP检查无异常.结论 BAEP检查为无创和客观测定,对老年人VBI的损伤部位(脑干或听神经通路)及损伤的程度都具有诊断意义,可作为老年人内耳型和脑干型病变定位的客观诊断指标.     

周围性眩晕和中枢性眩晕电生理特点的比较

目的比较周围性眩晕和中枢性眩晕的电生理特点。方法对周围性眩晕组(85例)和中枢性眩晕组(61例)患者进行眼震电图和脑干听觉诱发电位(BAEP)检查。结果周围性眩晕组眼震电图异常67例(78.8%),其中视测距障碍试验过冲及欠冲6例(7.1%);自发性眼震5例(5.9%);凝视试验异常16例(18.8%);视跟踪试验Ⅰ型42例(49.4%),Ⅱ型17例(20.0%),Ⅲ型8例(9.4%);视动性眼震试验双侧不对称19例(22.4%);变位性眼震阳性51例(60.0%);冷热试验异常31例(36.5%)。中枢性眩晕组眼震电图异常42例(68.9%),视测距障碍试验过冲及欠冲19例(31.1%);自发性眼震13例(21.3%);凝视试验异常23例(37.7%);视跟踪试验Ⅰ型35例(57.4%),Ⅱ型13例(21.3%),Ⅲ型8例(13.1%),Ⅳ型5例(8.2%);视动性眼震试验双侧不对称33例(54.1%);变位性眼震阳性2例(3.3%);冷热试验异常6例(9.8%)。与周围性眩晕组比较,中枢性眩晕组视测距障碍试验、凝视试验、视跟踪试验、视动性眼震试验异常率显著升高,变位实验和冷热实验异常率显著降低(均P0.05)。周围性眩晕组BAEP异常32例(37.6%),中枢性眩晕组BAEP异常31例(50.8%)。与中枢性眩晕组比较,周围性眩晕组Ⅰ波潜伏期及Ⅰ-Ⅲ波的波峰潜伏期显著升高,Ⅴ波潜伏期及Ⅰ-Ⅴ波峰潜伏期显著降低(均P0.05)。结论眼震电图视测距障碍试验、凝视试验、视跟踪试验、视动性眼震试验对中枢性眩晕敏感性较高,变位性眼震实验对耳石症检出率高,冷热实验对半规管功能评价敏感度高。BAEP阳性率较低,但可对眩晕患者定位提供客观依据。     

59例听神经瘤患者脑干听觉诱发电位分析

目的 分析听神经瘤(acoustic neuroma,AN)患者的脑干听觉诱发电位的变化特征及健侧耳峰间期改变.方法 对59例听神经瘤(AN)患者进行脑干听觉诱发电位(BAEP)检测,测定Ⅰ、Ⅲ、Ⅴ波潜伏期(PL)、峰间期(IPL),双耳PL、IPL之间差值(ILD)等数值.结合MRI、CT影象学资料进行分析,并与36例健康者对照.结果 AN组与正常对照组BAEP各波PL、IPL测值比较差异有极显著性(P＜0.01).AN患侧BAEP异常率98.3%(58/59);主要表现:①Ⅰ、Ⅲ、Ⅴ波缺失;②Ⅲ、Ⅴ波PL延长;③Ⅰ～Ⅲ、Ⅲ～Ⅴ、Ⅰ～Ⅴ波IPL延长.AN患者健侧BAEP的异常率69.5%(41/59),主要表现:①Ⅴ波PL延长;②Ⅲ～Ⅴ及Ⅰ～Ⅴ波IPL延长;③Ⅲ～Ⅴ/Ⅰ～Ⅲ波IPL比值＞1.肿瘤直径＞2cm,BAEP的异常率有显著提高.不同大小肿瘤组间健侧BAEP测值比较:健侧Ⅴ波PL差异有显著性(P＜0.05),Ⅲ～Ⅴ及Ⅰ～ⅤIPL差异有极显著性(P＜0.01).结论 BAEP对AN诊断具有重要意义,它为病变提供了定位诊断依据,尤其健侧Ⅲ～Ⅴ/Ⅰ～Ⅲ波IPL比值异常,是脑干受压的敏感指标.     

脑干听觉诱发电位在脑干实验性阶梯性压迫中的改变

本文报告32只兔定量脑干压迫BAEP的变化和术后24～36小时动物意识恢复状况及脑干病理检查结果。探讨了颅后凹手术中BAEP的改变与听神经和脑干功能的关系及有关BAEP指标。结果表明,术中BAEP改变有4种类型;术侧BAEP反映同侧听神经功能状况(Ⅰ、Ⅱ型),出现Ⅱ型改变时术后压迫侧有神经性耳聋;手术对侧BAEP反映上部脑干功能(Ⅲ、Ⅳ型),Ⅳ型动物术后均有严重的脑干损伤。作者认为,BAEP的I—V波间时程为2.62 0.54(均值加3SD)是脑干功能不可逆损害的临界值。     

后颅窝肿瘤患者脑干听觉诱发电位初步研究：20例MRI和CT对照分析

以 MRI 和 CT 为对照分析了20例脑干和小脑肿瘤患者脑干听觉诱发电位(BAEP)的检查结果,发现 BAEP 异常者19例,BAEP 正常者1例。BAEP 异常主要表现为:Ⅰ～Ⅶ各波消失,Ⅴ波波幅降低,波幅比Ⅴ/Ⅰ<1,波间期Ⅰ～Ⅲ、Ⅲ～Ⅴ和Ⅰ～Ⅴ延长,波间期比Ⅲ～Ⅴ/Ⅰ～Ⅲ>1,与 MRI 和 CT 结果对照分析表明除肿瘤本身以外,脑干受压移位、脑脊液通路受阻也是BAEP 异常、特别是病灶对侧异常的重要原因。     

脑干听觉诱发电位与后颅窝肿瘤

脑干听觉诱发电位(BAEP)用于后颅窝肿瘤的诊断已日益受到重视。本文总结分析57例后颅窝不同部位肿瘤的BAEP表现:CPA肿瘤BAEP可归纳为四种类型表现。其他后颅窝肿瘤的BAEP表现呈多样化,其波形的变化是从Ⅳ、Ⅴ波向Ⅲ、Ⅱ波发展;Ⅲ～VIPL比Ⅰ～ⅢIPL延长更显著;常呈双侧波形异常等为主,从而给后颅窝肿瘤的定位诊断提供了依据。     

后循环梗死患者的BAEP、BR、TSEP检测

目的:探讨后循环脑梗死(PCI)患者脑干听觉诱发电位(BAEP)、瞬目反射(BR)、三叉神经诱发电位(TSEP)三种电生理变化.方法:选择60例经头颅MRI检查证实为PCI患者(病例组),分别于人院一周之内行BAEP、BR、TSEP检查,观察BAEP波形及Ⅰ、Ⅲ、Ⅴ波潜伏期(PL)、峰间期(IPL),计算BR的R1、R2、R2′波平均PL、波幅及TSEP各成分PL,并与40例健康体检者作对照.结果:病例组60例中BAEP异常35例(58%),异常主要表现为Ⅰ、Ⅴ波的PL、Ⅰ-Ⅴ波的IPL延长和Ⅰ/Ⅴ波幅比＞1.BR异常33例(55%),异常主要表现为R2波的PL延长,R2、R2′波幅下降.TSEP检查病例组与对照组PL比较未见明显差异.结论:BAEP、BR两种电生理检查方法能够较好地检测出PCI患者神经功能异常,联合应用BAEP及BR能够为PCI患者的神经功能的判断提供重要参考.     

良性阵发性位置性眩晕患者脑干听觉诱发电位分析

目的探讨脑干听觉诱发电位(BAEP)对良性发作性位置性眩晕的诊断价值。方法对51例良性发作性位置性眩晕者进行BAEP检查,并以47名正常健康受试者作对照。结果 (1)良性阵发性位置性眩晕组BAEP异常率为49.02%;(2)与对照组相比,病例组右侧Ⅰ-Ⅴ峰间潜伏期延长,有统计学差异(P<0.05);(3)病例组左右两侧相比,右侧Ⅰ、Ⅲ、Ⅴ波潜伏期延长,有统计学差异(P<0.05)。结论 BAEP对于良性发作性位置性眩晕的诊断有一定价值。     

115例前庭系统性眩晕患者脑干听觉诱发电位分析

椎基底动脉缺血发作性眩晕是神经科常见的症状之一。眩晕分为前庭神经系统性眩晕和非前庭系统性眩晕。因病变部位不同，前庭系统性眩晕又分为中枢性眩晕和周围性眩晕。目前脑干听觉诱发电位（BAEP）在眩晕的病因诊断方面已成为一种重要的辅助手段。本文分析了我院2002年以来115例前庭系统性眩晕患者的脑干听觉诱发电位检查，现将其结果分析如下。     

脑干听觉诱发电位分级对脑创伤长期意识障碍患者清醒预测的价值

目的 探讨脑干听觉诱发电位(BAEP)分级标准对脑创伤后长期意识障碍患者清醒预测的价值.方法 分析93例脑创伤后长期意识障碍患者的BAEP表现,将BAEP分为3级:Ⅰ级为各波均正常;Ⅲ级为双侧V波PL异常、双侧Ⅲ～Ⅴ波IPL异常、单侧或双侧V波消失;Ⅱ级为除Ⅲ级之外的任何异常BAEP表现.以脑创伤后6个月作为判断是否清醒的时间标准.结果 Ⅰ级、Ⅱ级、Ⅲ级的清醒率分别为:79％、18％和0％.分级与清醒差异有统计学意义(r=-0.662,P＜0.001),分级越高,清醒越困难.BAEP分级标准对清醒预测的ROC曲线下面积为0.859,95％可信区间为(0.781～0.937).结论 BAEP分级能客观、准确地反映脑功能损伤程度和预测清醒的概率.     

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.     

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.     

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.     

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.     

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.     

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.     

Special Pharmacokinetic Considerations in Children

Summary: Pediatric patients have greater degrees of pharmacokinetic variability and unpredictability than adults. This variability results from the effects of pharmacogenetics, age and growth, prior and current comedication, and disease. Newborns with seizures have the least predictable dosage requirements, and their needs change as drug-eliminating mechanisms mature in the neonatal period. Infants have the highest relative capacities to eliminate antiepileptics of any age group and require the largest relative doses. In addition to age-related trends, children demonstrate the same drug-specific, pharmacokinetic phenomena that adults do, including nonlinear phenytoin elimination, nonlinear valproate binding, and autoinduction of carbamazepine. Intercurrent illness and drug interactions further modify the age-related pharmacokinetic patterns in children and make dosage requirements even more unpredictable. Recent studies have shown that febrile illness can affect drug elimination, sometimes decreasing drug levels by 50% or more. Intermittent treatment with benzodiazepines administered either orally or rectally can be an important adjunct and help minimize this type of problem for children with marginally controlled epilepsy. Intermittent benzodiazepines are also helpful for children who have febrile seizures and who need only occasional antiepileptic protection.