儿科抗癫痫药物应用研究进展

儿童癫痫为小儿神经科的常见疾病,临床表现以抽搐为主。近年来,随着医疗技术的发展,以及人们对儿童癫痫的重视,国内外文献对儿科癫痫的治疗报道越来越多,目前,药物治疗仍然是抗癫痫的首选方法,除了运用新型抗癫痫药物外,也有采用中药治疗癫痫的报道,现就近年来儿童癫痫的药物治疗研究作一综述。     

MicroRNA与癫痫的研究进展

癫痫是大脑神经元高度同步化异常放电所导致的短暂的大脑功能障碍的一种慢性疾病。癫痫的发病原因十分复杂,目前主要治疗方式是药物治疗,但仍然有30%左右的难治性癫痫患者依靠药物治疗未能控制癫痫发作,因此从分子角度研究癫痫的发病机制及治疗是近年来癫痫研究的热点。微小RNA(miRNA)在癫痫患者及癫痫动物模型海马组织中存在差异性表达,通过抑制miRNA的差异表达在一定程度上可以缓解癫痫的症状,这为癫痫的治疗开辟了新的途径和方向。因此随着miRNA与癫痫相关性研究深度的不断加深,有望能够为癫痫的诊断及治疗提供一个全新的思路。     

Sex hormones in patients with epilepsy-hormonal changes in epileptic men and women taking antiepileptics.

The relationship between epilepsy and endocrine system has attracted the attention of investigators for a number of years. Epilepsy is a common neurological disorder; both seizures and antiepileptic drugs can compromise the physical and hormonal aspects of sexual development. Impairment of libido and sexual potency have been frequently reported in male epileptic patients. Women with epilepsy have a greater risk of infertility (anovulatory cycles and polycystic ovary syndrome). This review analyses the main data from the literature in order to clarify the role of epilepsy and antiepileptic drugs on sex hormones in epileptic patients. As gonad dysfunction is frequently observed in women and men with epilepsy, particularly when taking antiepileptic drugs, ovarian and testicular function must be carefully monitored.     

膜超极化激活离子通道及其靶向抗癫痫药物研究进展

癫痫是一种较为常见的神经系统疾病,主要以大量神经元同步异常放电为特征。目前普遍认为,神经元或神经网络兴奋性和抑制性 电信号传输的失衡,是癫痫发病的最根本原因。现有的抗癫痫药物主要以钠离子通道、钙离子通道、钾离子通道、谷氨酸受体和γ-氨基丁 酸离子通道为靶点,但接受这些药物治疗后,仍有近1/3的病人无法控制癫痫发作。因此,抗癫痫药物的研发亟需新靶点和新思路。许多 研究证据表明,膜超极化激活离子通道的基因突变可以导致遗传型癫痫的发作,且在脑部损伤后,膜超极化激活离子通道会发生表达水平、 通道生物物理学性质及通道亚基构成的改变,从而增加神经元和神经网络兴奋性,促使癫痫发病。故近年来,膜超极化激活离子通道及其 靶向抗癫痫药物研究引起人们广泛关注。综述膜超极化激活离子通道与癫痫发病之间的关系,并探讨以膜超极化激活离子通道为靶点进行 抗癫痫药物开发和治疗的可行性。     

Prognostic index for recurrence of seizures after remission of epilepsy. Medical Research Council Antiepileptic Drug Withdrawal Study Group.

OBJECTIVES--To develop and test a prognostic index for the recurrence of seizures after a minimum remission of seizures of two years in people with a history of epilepsy. DESIGN--Information from a large prospective randomised study of withdrawal of antiepileptic drugs was used to identify clinical and treatment factors of prognostic importance in determining the recurrence of seizures. A split sample approach was used to test the internal validity of predictions made on the basis of identified prognostic factors. SETTING--Centres in six European countries. MAIN OUTCOME MEASURES--Comparison of predicted and observed rates of recurrence of seizure. SUBJECTS--1013 patients randomised to the Medical Research Council study for antiepileptic drug withdrawal. RESULTS--The Cox proportional hazards model identified several factors that increased the risk of seizures recurring. These included being 16 years or older; taking more than one antiepileptic drug; experiencing seizures after starting antiepileptic drug treatment; a history of primary or secondarily generalised tonic-clonic seizures; a history of myoclonic seizures; and having an abnormal electroencephalogram. The risks of seizures recurring decreased with increasing time without seizures. The model allowed estimation of the risk of seizures recurring in the next one and two years under the policies of continued antiepileptic drug treatment and slow withdrawal of drugs. Split sample validation suggested that the model was well calibrated. CONCLUSION--The model is currently the best available aid for counselling the many patients in the community with epilepsy currently in remission who seek advice about the risks of seizures recurring if they stop antiepileptic drug treatment. The model requires validation in a broad population of patients, and such studies are in progress.     

Effect of Antiepileptic Drugs for Acute and Chronic Seizures in Children with Encephalitis

BackgroundEncephalitis presents with seizures in the acute phase and increases the risk of late unprovoked seizures and epilepsy. This study aimed to evaluate the effect of antiepileptic drugs in pediatric patients with acute seizures due to encephalitis and epilepsy.ResultsDuring the study period, 1038 patients (450 girls, 588 boys) were enrolled. Among them, 44.6% (463) had seizures in the acute phase, 33% had status epilepticus, and 26% (251) developed postencephalitic epilepsy. At one year of follow-up, 205 of the 251 patients with postencephalitic epilepsy were receiving antiepileptic drugs while 18% were seizure free even after discontinuing the antiepileptic drugs. Among those with postencephalitic epilepsy, 67% had favorable outcomes and were using <2 anti-epileptic drugs while 15% had intractable seizures and were using ≥ 2 antiepileptic drugs. After benzodiazepines, intravenous phenobarbital was preferred over phenytoin as treatment of postencephalitic seizures in the acute phase. For refractory status epilepticus, high-dose topiramate combined with intravenous high-dose phenobarbital or high-dose lidocaine had less side effects.ConclusionsChildren with encephalitis have a high rate of postencephalitic epilepsy. Phenobarbital and clonazepam are the most common drugs used, alone or in combination, for postencephalitic epilepsy.     

ABCB1基因多态性与难治性癫痫

近年来,难治性癫痫的病因与多药耐药基因以及多药耐药基因与抗癫痫治疗的因果关系越来越受到关注。P糖蛋白(P-glycopretein,P-gp)是由ATP结合盒B亚家族成员1转运蛋白基因(ATP-binding cassette subfamily B member 1 transporter gene,ABCB1)编码的产物。它不仅可以限制抗癫痫药物(antiepileptic drug,AED)的消化道吸收,而且可以在细胞和亚细胞水平调控药物在中枢神经系统的运输过程。除了生理和环境因素的影响,P-gp的功能和表达的变化可能主要取决于ABCB1基因的多态性,这是目前研究得最广泛、最深入的多药耐药机制。本文就目前ABCB1基因多态性与难治性癫痫的相关性研究进展作一综述。     

Recent advances in drug therapy for epilepsy.

Recent advances in drug therapy for epilepsy have contributed to the reduction in the proportion of persons whose epilepsy is uncontrolled. New knowledge of the pharmacokinetics of phenytoin has led to a better understanding of the drug''s bioavailability and uses. Carbamazepine has recently been introduced for the treatment of generalized tonic-clonic and partial seizures. Clonazepam has been found of particular benefit in the treatment of absence and myoclonic seizures. Valproic acid is a promising antiepileptic drug with broad-spectrum activity, and is particularly useful in the treatment of absence and myoclonic seizures, although further clinical experience is required before it can supplant ethosuximide as the preferred drug for the treatment of absence seizures. Monitoring of the plasma concentration of antiepileptic drugs has added greatly to the achievement of optimal drug therapy and the prevention of toxic effects.     

Nesfatin-1 and ghrelin levels in serum and saliva of epileptic patients: hormonal changes can have a major effect on seizure disorders

Nesfatin-1 and ghrelin are the two recently discovered peptide hormones involved in the control of appetite. Besides its main appetite-control function, ghrelin also has anticonvulsant effects, while nesfatin-1 causes depolarization in the paraventricular nucleus (PVN). The aims of this study, therefore, were to investigate: (i) whether there are differences in the concentrations of nesfatin-1 and ghrelin in saliva and serum samples between eplilepsy patients and normal controls and (ii) whether salivary glands produce nesfatin-1. The study included a total of 73 subjects: 8 patients who were newly diagnosed with primary generalized seizures and had recently started antiepileptic drug therapy; 21 who had primary generalized seizures and were continuing with established antiepileptic drug therapy; 24 who had partial seizures (simple: n = 12 or complex: n = 12) and were continuing with established antiepileptic drug therapy; and 20 controls. Salivary gland tissue samples were analyzed for nesfatin-1 expression by immunochemistry and ELISA. Saliva and serum ghrelin levels were measured by ELISA and RIA, and nesfatin-1 levels by ELISA. Nesfatin-1 immunoreactivity was detected in the striated and interlobular parts of the salivary glands and the ducts. The nesfatin-1 level in the brain was around 12 times higher than in the salivary gland. Before antiepileptic treatment, both saliva and serum nesfatin-1 levels were around 160-fold higher in patients who are newly diagnosed with primary generalized epilepsy (PGE) than in controls; these levels decreased with treatment but remained about 10 times higher than the control values. Saliva and serum nesfatin-1 levels from patients with PGE and partial epilepsies who were continuing antiepileptic drugs were also 10-fold higher than control values. Serum and saliva ghrelin levels were significantly (twofold) lower in epileptic patients before treatment than in controls; they recovered somewhat with treatment but remained below the control values. These results suggest that the low ghrelin and especially the dramatically elevated nesfatin-1 levels might contribute to the pathophyisology of epilepsy. Therefore, serum and saliva ghrelin and especially the remarkably increased nesfatin-1 might be candidate biomarkers for the diagnosis of epilepsy and for monitoring the response to anti-epileptic treatment.     

Guidelines for treating epilepsy in the age of felbamate,vigabatrin, lamotrigine,and gabapentin.

For the first time in 15 years, new antiepileptic medications are available for the treatment of patients with seizure disorders. These drugs have demonstrated efficacy in animal models of epilepsy and in controlled clinical trials. Felbamate was licensed in 1993 for use as adjunctive therapy or monotherapy in adults with partial or tonic-clonic seizures and as adjunctive therapy for children with the Lennox-Gastaut syndrome. Gabapentin was approved January 1994 as adjunctive therapy in patients 12 years or older with partial seizures, with or without secondary generalization. Lamotrigine is expected to be approved this year for the treatment of partial and tonic-clonic seizures in adults. Last, a new drug application has been filed for vigabatrin this year, with possible licensing next year. These four anticonvulsants present new options in the treatment of patients with refractory epilepsy and are not merely congeners of previously available treatments. They have unique clinical spectrums and are reported to be safer and better tolerated than conventional therapy. Trials to compare their use with that of conventional therapy have not been done, and their use in the initial treatment of patients with epilepsy is not completely clear.     

血脑屏障上P-糖蛋白与耐药性癫痫关系的研究进展

耐药性癫痫是癫痫治疗的瓶颈。P-糖蛋白通过跨膜外排泵作用阻止抗癫痫药物由血脑屏障入脑发挥期望效应是耐药性癫痫产生的重要原因。本文介绍了耐药性癫痫与血脑屏障上P-糖蛋白的相互关系,对目前提出的调节P-糖蛋白功能,改善耐药性癫痫预后应注意的问题进行说明。安全地调节P-糖蛋白功能到适度可能为耐药性癫痫的治疗带来希望。     

Intelligence and physical features of children of women with epilepsy

The teratogenicity of maternal epilepsy has been attributed to several factors, including the antiepileptic drugs taken to prevent seizures during pregnancy, the occurrence of seizures during pregnancy, and the factors in the mother that caused her to have epilepsy. We have addressed the hypothesis that the children of women who have a history of epilepsy (seizure history), but who took no antiepileptic drugs (AED) and had no tonic-clonic seizures in pregnancy, have an increased risk of malformations and diminished intelligence. The frequency of cognitive dysfunction was determined in 57 seizure history and 57 matched control children aged 6-l6 years. The masked evaluation of the children included a physical and neurologic examination and testing with the Wechsler Intelligence Scale for Children-Revised (WISC-R) and a systematic physical examination for the features of the fetal AED syndrome. The evaluation of both parents of each child included a test of reasoning (Ravens Progressive Matrix) and a physical examination. There were no differences between the two groups of children in either IQ scores or physical features; none of the seizure history children was judged to have the "anticonvulsant face" or digit hypoplasia. This study had 80% power to rule out a difference of seven or more IQ points between the two groups, based on a two-sided test at a 5% level of significance. Our confidence in concluding that there was no difference between seizure history and control infants was strengthened by the fact that no statistically significant differences were observed with respect to multiple outcomes, including eight related measures of intelligence. Thirty (53%) of the seizure history mothers resumed taking AED after the birth of the child we evaluated. Additional studies are needed to address the teratogenicity of the antiepileptic drugs as monotherapy.     

When do epileptic patients need treatment? Starting and stopping medication.

Decisions about when to start and stop antiepileptic treatment have important implications for patients with epilepsy. Clinical practice varies and is determined more by dogmatic teaching than by knowledge of either the clinical course of epilepsy or the influence of the drugs. A review of the available evidence shows the need for further studies on the effects of starting and withdrawing treatment on the clinical course and prognosis of epilepsy.     

The influence of competing-risks setting on the choice of hypothesis test for treatment effect

There is considerable debate regarding the choice of test for treatment difference in a randomized clinical trial in the presence of competing risks. This question arose in the study of standard and new antiepileptic drugs (SANAD) trial comparing new and standard antiepileptic drugs. This paper provides simulation results for the log-rank test comparing cause-specific hazard rates and Gray's test comparing cause-specific cumulative incidence curves. To inform the analysis of the SANAD trial, competing-risks settings were considered where both events are of interest, events may be negatively correlated, and the degree of correlation may differ in the 2 treatment groups. In settings where there are effects in opposite directions for the 2 event types, a likely situation for the SANAD trial, Gray's test has greater power to detect treatment differences than log-rank analysis. For the epilepsy application, conclusions were qualitatively similar for both log-rank and Gray's tests.     

Mechanisms of Action of Carbamazepine and Its Derivatives,Oxcarbazepine, BIA 2-093, and BIA 2-024

Carbamazepine (CBZ) has been extensively used in the treatment of epilepsy, as well as in the treatment of neuropathic pain and affective disorders. However, the mechanisms of action of this drug are not completely elucidated and are still a matter of debate. Since CBZ is not very effective in some epileptic patients and may cause several adverse effects, several antiepileptic drugs have been developed by structural variation of CBZ, such as oxcarbazepine (OXC), which is used in the treatment of epilepsy since 1990. (S)-(–)-10-acetoxy-10,11-dihydro-5H-dibenz[b,f]azepine-5-carboxamide (BIA 2-093) and 10,11-dihydro-10-hydroxyimino-5H-dibenz[b,f]azepine-5-carboxamide (BIA 2-024), which were recently developed by BIAL, are new putative antiepileptic drugs, with some improved properties. In this review, we will focus on the mechanisms of action of CBZ and its derivatives, OXC, BIA 2-093 and BIA 2-024. The available data indicate that the anticonvulsant efficacy of these AEDs is mainly due to the inhibition of sodium channel activity.     

Inhibition of Death-associated Protein Kinase 1 protects against Epileptic Seizures in mice

Epilepsy is a chronic encephalopathy and one of the most common neurological disorders. Death-associated protein kinase 1 (DAPK1) expression has been shown to be upregulated in the brains of human epilepsy patients compared with those of normal subjects. However, little is known about the impact of DAPK1 on epileptic seizure conditions. In this study, we aim to clarify whether and how DAPK1 is regulated in epilepsy and whether targeting DAPK1 expression or activity has a protective effect against epilepsy using seizure animal models. Here, we found that cortical and hippocampal DAPK1 activity but not DAPK1 expression was increased immediately after convulsive pentylenetetrazol (PTZ) exposure in mice. However, DAPK1 overexpression was found after chronic low-dose PTZ insults during the kindling paradigm. The suppression of DAPK1 expression by genetic knockout significantly reduced PTZ-induced seizure phenotypes and the development of kindled seizures. Moreover, pharmacological inhibition of DAPK1 activity exerted rapid antiepileptic effects in both acute and chronic epilepsy mouse models. Mechanistically, PTZ stimulated the phosphorylation of NR2B through DAPK1 activation. Combined together, these results suggest that DAPK1 regulation is a novel mechanism for the control of both acute and chronic epilepsy and provide new therapeutic strategies for the treatment of human epilepsy.     

Amino Acid Levels in the Cerebrospinal Fluid of Newly Diagnosed Epileptic Patients: Effect of Vigabatrin and Carbamazepine Monotherapies

Abstract: We studied the CSF amino acid levels of 42 patients with newly diagnosed epilepsy before treatment with antiepileptic medication and during monotherapy with either vigabatrin or carabamzepine. The present study shows that patients with newly diagnosed epilepsy have elevated levels of the excitatory amino acid glutamate in CSF. Vigabatrin monotherapy effectively prevents the appearance of seizures in patients with high baseline CSF glutamate levels. In these patients, vigabatrin not only elevates the levels of γ-aminobutyric acid, but also decreases the elevated levels of glutamate in CSF, which may also be important to the antiepileptic efficacy of vigabatrin. Patients with low CSF glutamate levels did not benefit from vigabatrin-induced changes in amino acid levels and successful monotherapy with carbamazepine did not affect CSF amino acid levels. The elevation of γ-aminobutyric acid is thus not the only way to achieve seizure control and there are several factors underlying the generation and control of seizures. Follow-up of the patients with high baseline glutamate CSF levels will show if the observed abnormalities are related to the severity of epilepsy in individual patients and if early treatment with vigabatrin of these patients could prevent the development of intractable epilepsy.     

海马脑片抗癫痫药物研究的离体模型

目的：建立离体海马脑片癫痫样放电模型并用于抗癫痫药物研究。方法：在豚鼠海马脑片上灌流青霉素建立颠阗痫样放电的离体模型。并用此模型对抗癫痫药物苯巴比妥钠和苯妥英钠两种药物在不同浓度下对癫痫样放电的对抗作用进行了定量分析,结果：在海马脑片上灌流致痫药物可建立一个较好的离体组织癫痫样放电模型,苯的对抗作用进行了定量分析,结果：在海马脑片上灌流致痫药物可建立一个较好的离体组织癫痫样放电模型。苯巴比妥和苯妥英钠在一定浓度下均有显著对抗癫痫样放电的作用,且与整体实验的结果相一致。结论：本实验建立有离体脑片模型具有实验手段简单,方法灵活,易于建立药物量效关系等优点,可用于抗癫痫药物筛选和研究。     

Solitary epileptic seizure--the risk of recurrence

Patients experiencing solitary unprovoked epileptic seizure have different risks of recurrence. The possible risk factors include in particular: structural cerebral lesion and its cause, history of febrile seizures, family history of epilepsy, the type of seizure, epileptiform EEG discharges and the problem of initiation or (or not initiation) of antiepileptic treatment after the first paroxysm. The factors shown above were evaluated in a group of 30 patients with solitary unprovoked epileptic seizure. Regarding recurrence of epileptic seizure, the only significant factor appeared to be initiation of treatment after the first unprovoked paroxysm (p<0.001). We observed a 30% and 33.33% risk of recurrence following the initial epileptic seizure in patients after the first unprovoked seizure in less than 1 and 3 years, respectively.     

Neurocysticercosis as a Cause of Epilepsy and Seizures in Two Community-Based Studies in a Cysticercosis-Endemic Region in Peru

Background

The prevalence of epilepsy added to inadequate treatment results in chronic morbidity and considerable mortality in poor populations. Neurocysticercosis (NCC), a helminthic disease of the central nervous system, is a leading cause of seizures and epilepsy in most of the world.

Methods

Taking advantage of a cysticercosis elimination program, we performed two community-based cross-sectional studies between 2006 and 2007 in 58 rural communities (population 20,610) to assess the prevalence and characteristics of epilepsy and epileptic seizures in this endemic region. Serological and computed tomography (CT) data in individuals with epilepsy were compared to previous surveys in general population from the same region.

Principal findings

In two surveys, 17,450 individuals were evaluated. Lifetime prevalence of epilepsy was 17.25/1000, and prevalence of active epilepsy was 10.8/1000 inhabitants. The prevalence of epilepsy increased after age 25 years and dropped after age 45. Only 24% (45/188) of patients with active epilepsy were taking antiepileptic drugs, all at sub-therapeutic doses. Antibodies to cysticercosis were found in approximately 40% of individuals with epilepsy in both studies. In one survey only individuals presenting strong antibody reactions were significantly associated with having epilepsy (OR 5.74; p<0.001). In the second, the seroprevalence as well as the proportion presenting strong antibody reactions were both significantly higher in individuals with epilepsy (OR 2.2 and 4.33, respectively). Brain CT showed NCC-compatible images in 109/282 individuals with epilepsy (39%). All individuals with viable parasites on CT were seropositive.

Conclusion

The prevalence of epilepsy in this cysticercosis endemic region is high and NCC is an important contributor to it.