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Carlos Eduardo Silvado,1 Vera Cristina Terra,1 Carlos Alexandre Twardowschy2 1Comprehensive Epilepsy Program, Hospital de Clinicas, Federal University of Parana (UFPR), Curitiba, Brazil; 2Department of Neurology, Catholic University of Parana (PUCPR), Curitiba, Brazil Abstract: Phenytoin (PHT) is an antiepileptic drug widely used in the treatment of focal epilepsy and status epilepticus, and effective in controlling focal seizures with and without tonic–clonic generalization and status epilepticus. The metabolization of PHT is carried out by two oxidative cytochrome P450 enzymes CYP2C9 and CYP2C19; 90% of this metabolization is done by CYP2C9 and the remaining 10% by CYP2C19. Genetic polymorphism of CYP2C9 may reduce the metabolism of PHT by 25–50% in patients with variants *2 and *3 compared to those with wild-type variant *1. The frequency distribution of CYP2C9 polymorphism alleles in patients with epilepsy around the world ranges from 4.5 to 13.6%, being less frequent in African-Americans and Asians. PHT has a narrow therapeutic range and a nonlinear pharmacokinetic profile; hence, its poor metabolization has significant clinical implications as it causes more frequent and more serious adverse effects requiring discontinuation of treatment, even if it had been effective. There is evidence that polymorphisms of CYP2C9 and the use of PHT are associated with an increase in the frequency of some side effects, such as cerebellar atrophy, gingival hypertrophy or acute cutaneous reactions. The presence of HLA-B*15:02 and CYP2C9 *2 or *3 in the same patient increases the risk of Stevens–Johnson syndrome and toxic epidermal necrolysis; hence, PHT should not be prescribed in these patients. In patients with CYP2C9 *1/*2 or *1/*3 alleles (intermediate metabolizers), the usual PHT maintenance dose (5–10 mg/kg/day) must be reduced by 25%, and in those with CYP2C9 *2/*2, *2/*3 or *3/*3 alleles (poor metabolizers), the dose must be reduced by 50%. It is controversial whether CYP2C9 genotyping should be done before starting PHT treatment. In this paper, we aim to review the influence of CYP2C9 polymorphism on the metabolization of PHT and the clinical implications of poor metabolization in the treatment of epilepsies. Keywords: phenytoin, antiepileptics, CYP2C9, cytochrome P450, epilepsy, polymorphisms, adverse effects

Epilepsy is a potentially devastating brain disorder characterized by a predisposition to spontaneous epileptic seizures. In patients with medically refractory epilepsy, new non-pharmacological therapeutic approaches may be considered. In this scenario, palliative surgery such as vagus nerve stimulation (VNS) or deep brain stimulation (DBS) may be indicated in a subset of patients. In this paper we make recommendations for the use of VNS and DBS in patients in Brazil with refractory epilepsy. RESUMO Epilepsia é uma doença cerebral potencialmente devastadora caracterizada por predisposição em gerar crises epilépticas espontâneas. Em pacientes com epilepsia refratária novas abordagens terapêuticas, não farmacológicas, podem ser consideradas. Neste cenário, cirurgias paliativas, como a estimulação do nervo vago (VNS) ou estimulação cerebral profunda (DBS) podem ser indicadas em um subgrupo de pacientes. Neste trabalho sugerimos recomendações sobre as indicações de uso do VNS e do DBS em pacientes com epilepsia refratária no Brasil.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) INCT/MCT Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The incidence of sudden unexpected death in epilepsy (SUDEP) has been estimated from 0.5-1.4/1,000 person-years in people with treated epilepsy, and 9/1,000 person-years in candidates for epilepsy surgery. Potential risk factors for SUDEP include: age, early onset of epilepsy, duration of epilepsy, uncontrolled seizures, seizure type and winter temperatures. The arrythmogenic side-effect of antiepileptic drugs and seizures may increase the risk of SUDEP. In this report, we describe a patient with prolonged post-ictal tachycardia in EEG video recordings with a typical case of SUDEP: a 16-year-old boy with medically intractable complex partial seizures. Magnetic resonance imaging revealed left mesial temporal sclerosis. During non-invasive video-EEG monitoring, the patient presented a post-ictal heart rate increased for five hours. Two months after video-EEG, he died from SUDEP during a tonic-clonic secondary generalized seizure. The possibility of cardiac involvement in the pathogenesis of SUDEP has been suggested by many studies. Evaluation of this patient with EEG-video monitoring, including measurement of heart rate, contributed to an identification of ictal tachycardia that may have played a role in the SUDEP. Premature mortality seems to be increased in patients with epilepsy, and cardiac abnormalities may be a possible cause of SUDEP. (Cardiol J 2011; 18, 2: 194-196) Univ Sao Paulo, Ctr Cirurgia Epilepsia, Dept Neurociencias & Ciencias Comportamento, Fac Med Ribeirao Preto,Ctr Cirurgia Epilepsia CIR, BR-14048900 Sao Paulo, Brazil Univ Fed Sao Paulo, Disciplina Neurol Expt, Escola Paulista Med UNIFESP EPM, Sao Paulo, Brazil Univ Fed Sao Paulo, Dept Fisiol, Escola Paulista Med UNIFESP EPM, Sao Paulo, Brazil Univ Fed Sao Paulo, Disciplina Neurol Expt, Escola Paulista Med UNIFESP EPM, Sao Paulo, Brazil Univ Fed Sao Paulo, Dept Fisiol, Escola Paulista Med UNIFESP EPM, Sao Paulo, Brazil Web of Science

OBJECTIVES: Patients that undergo epilepsy surgery for temporal lobe epilepsy (TLE) in the dominant hemisphere are more susceptible to naming deficits. The aim of the present study was to perform an observational retrospective study comparing two groups of patients for naming performance, those with left and right temporal lobe resections regarding the performance in naming by Boston Naming Test (BNT). METHODS: A total of 120 right-handed patients (52 right temporal lobe and 68 left temporal lobe), aged between 18 and 59, with pharmacoresistant mesial TLE were retrospectively analyzed. All patients underwent pre and postoperative neuropsychological assessment. RESULTS AND CONCLUSIONS : The BNT was a good predictor for possible post-surgical language deficits in patients submitted to left temporal lobectomy. OBJETIVO: Pacientes submetidos a cirurgia de epilepsia portadores de epilepsia do lobo temporal (ELT) em hemisfério dominante são mais suscetíveis a apresentarem déficits de nomeação. O objetivo do presente estudo foi realizar um estudo retrospectivo observacional comparando dois grupos de pacientes sendo um grupo submetido a lobectomia temporal dominante e outro a lobectomia temporal não dominante em relação ao desempenho na tarefa de nomeação através do Boston Naming Test (BNT). METÓDOS: Um total de 120 pacientes destros foram retrospectivamente analisados (52 temporal direito e 68 temporal esquerdo) com idade entre 18 e 59 anos, com epilepsia do lobo temporal mesial fármaco resistente. Todos os pacientes foram submetidos a avaliação neuropsicológica pré e pós-operatória utilizando o BNT para medida de nomeação. RESULTADOS E CONCLUSÕES: O BNT foi mostrou-se um bom instrumento para predizer possíveis déficits de linguagem em pacientes submetidos a lobectomia temporal esquerda.

Epilepsy Surgery in Children

Sudden Unexpected Death in Epilepsy: An Overview

Individuals with epilepsy are at higher risk of sudden unexpected death in epilepsy (SUDEP), responsible for 7.5% to 17% of all deaths in epilepsy. Many factors are current associated with SUDEP and possible effect of stress and cardiac arrhythmia are still not clear. Sudden death syndrome (SDS) in chickens is a disease characterized by an acute death of well-nourished and seeming healthy Gallus gallus after abrupt and brief flapping of their wings, similar to an epileptic seizure, with an incidence estimated as 0.5 to 5% in broiler chickens. A variety of nutritional and environmental factors have been included: but the exactly etiology of SDS is unknown. Studies had suggested that the hearts of broiler chickens are considerably more susceptible to arrhythmias and stress may induce ventricular arrhythmia and thus, sudden cardiac death. In this way, SDS in Gallus gallus could be an interesting model to study SUDEP. Indivíduos com epilepsia têm maior risco de sofrer morte súbita e inexplicada em epilepsia (SUDEP), responsável por 7,5% a 17% de todas as mortes em epilepsia. Diversos fatores têm sido associados com SUDEP e um possível efeito do stress e das arritmias cardíacas ainda não é claro. A síndrome da morte súbita (SDS) em galinhas é uma situação caracterizada por uma morte aguda em Gallus gallus bem nutridos e aparentemente saudáveis após um evento curto e abrupto de bater de asas, semelhante a uma crise epiléptica, com incidência de 0,5 a 5% em granjas. Uma ampla variedade de fatores nutricionais e ambientais tem sido considerada, mas a causa exata da SDS é desconhecida. Estudos têm sugerido que o coração das galinhas criadas em granjas é mais sensível a arritmias cardíacas e que o stress poderia levar a arritmias cardíacas e, portanto, a morte súbita cardíaca. Assim, SDS em Gallus gallus pode ser considerado um interessante modelo de SUDEP.

BACKGROUND AND PURPOSE: Rasmussen Encephalitis (RE) is characterized by intractable epilepsy, progressive hemiparesis and unilateral hemispheric atrophy. The progression of the symptoms usually occurs within months to few years. Antiepileptic drugs are usually not effective to control disease progression and epilepsy surgery in the form of hemispheric disconnection has been considered the treatment of choice. This work describes the clinical and electrographic analyses, as well as the post-operative evolution of patients with RE. PATIENTS AND METHODS: This work includes all the patients with RE evaluated from January 1995 to January 2008 by the Ribeirão Preto Epilepsy Surgery Program (CIREP) considering demographic data, interictal and ictal electroencephalographic (EEG) findings; anatomo-pathological findings and clinical outcome. RESULTS: Twenty-five patients were evaluated, thirteen were female. Mean age of epilepsy onset was 4.4±2.0 years. There were no differences between patients with slow and fast evolution with respect to age of epilepsy onset (p=0.79), age at surgery (p=0.24), duration of epilepsy (0.06), and follow-up (p=0.40). There were no correlations between the presence of bilateral EEG abnormalities or the absence of spikes and post-operative seizure outcome (p=0.06). Twenty-three patients underwent surgery. The mean follow-up was 75.3 months. Eleven patients had total seizure control. Twelve individuals persisted with seizures consisting of mild facial jerks (6 patients), occasional hemigeneralized tonic-clonic seizures (3 patients), and frequent tonic-clonic seizures (3 patients). Mental and language impairment was observed in 15 and 12 patients, after surgery, respectively. CONCLUSIONS: This retrospective study reported the clinical and electrographic analysis, as well as the evolution of 23 patients with RE. Fourteen patients achieved satisfactory seizure control, three patients had partial response to surgery, and five patients had maintenance of the pre-operative condition. All patients with left side involvement presented with some language and cognitive disturbance. INTRODUÇÃO E OBJETIVOS: A Encefalite de Rasmussen (ER) é caracterizada por epilepsia intratável, hemiparesia progressiva e atrofia hemisférica unilateral. A progressão dos sintomas geralmente ocorre em meses ou poucos anos. As drogas antiepilépticas são usualmente ineficazes no controle da progressão da doença e o tratamento cirúrgico, com desconexão hemisférica tem sido considerado o tratamento de escolha. Neste trabalho descreveremos os achados clínicos e eletrográficos, assim como a evolução pós-operatória de pacientes com ER. PACIENTES E MÉTODOS: foram incluídos todos os pacientes com ER avaliados no período de janeiro de 1995 a janeiro de 2008, no Centro de Cirurgia de Epilepsia de Ribeirão Preto (CIREP), sendo considerados os dados demográficos, os achados do eletrencefalograma (EEG) interictal e ictal, resultado anatomo-patológico e o seguimento clínico. RESULTADOS: Vinte e cinco pacientes foram avaliados, 13 eram do sexo feminino. A idade média de início da epilepsia foi de 4.4±2.0 anos. Não houve diferenças significativas entre os pacientes com evolução lenta ou rápida considerando-se a idade de início da epilepsia (p=0,79), idade da cirurgia (p=0,24), duração da epilepsia (p=0,06) e tempo de seguimento (p=0,40). Não houve correlação entre a presença de alterações bilaterais ou ausência de descargas ao EEG e o seguimento pós-operatório (p=0,06). Vinte e três pacientes foram submetidos à cirurgia. O tempo médio de seguimento foi de 75,3 meses. Onze pacientes evoluíram com controle total das crises. Doze pacientes permaneceram com crises que consistiram de clonias faciais sutis (6 pacientes), crises tônico-clônicas hemigeneralizadas ocasionais (3 pacientes) ou crises tônico-clônicas frequentes (3 pacientes). Alterações cognitivas e de linguagem foram observadas em 15 e 12 pacientes após a cirurgia, respectivamente. CONCLUSÕES: este estudo retrospectivo relatou os achados clínicos, eletrográficos e a evolução de 23 pacientes. Controle satisfatório das crises foi obtido em 14 pacientes. Três pacientes tiveram resposta parcial com a cirurgia e cinco pacientes mantiveram o quadro pré-operatório. Todos os pacientes com envolvimento do hemisfério cerebral esquerdo evoluíram com distúrbio de linguagem e cognitivo.

People with epilepsy are more likely to die prematurely and the most common epilepsy-related category of death is sudden unexpected death in epilepsy (SUDEP). Several studies have reported a moderate or high seizure frequency among SUDEP cases and SUDEP is considered rare in patients in remission. METHOD: We reviewed the occurrence of SUDEP in our epilepsy unit over an 8-year period to identify a potential association between seizure frequency and SUDEP occurrence in children with epilepsy. RESULTS: From 835 patients evaluated, 12 had suffered SUDEP and nearly all of the SUDEP cases in our children are related to chronic uncontrolled epilepsy (daily - 50.0%, two to four/week - 41.7%, monthly - 8.3%). CONCLUSION: SUDEP is not a rare event in children and increased mortality was recorded in those individuals who had not responded to pharmacologic treatment. Improved seizure control seems to be one of the most important measures to prevent SUDEP. Pessoas com epilepsia têm maior chance de morrer prematuramente e a principal causa de morte relacionada à epilepsia é a morte súbita em epilepsia (SUDEP). Vários estudos têm relatado uma freqüência de crises moderada ou elevada em pacientes com SUDEP e SUDEP é considerada rara em pacientes em remissão. MÉTODO: Revisamos a ocorrência de SUDEP em nossa unidade de epilepsia por um período de oito anos com o objetivo de identificar uma possível associação entre freqüência de crises e a ocorrência de SUDEP em crianças com epilepsia. RESULTADOS: De 835 pacientes avaliados, 12 evoluíram com SUDEP e a maioria das crianças apresentava epilepsia crônica não controlada (50% com crises diárias; 41,7% com duas a quatro crises/semana; 8,3% com crises mensais). CONCLUSÃO: SUDEP não é um evento raro em crianças e maior mortalidade foi observada em indivíduos que não responderam ao tratamento medicamentoso. Melhor controle de crises parece ser uma das principais medidas na prevenção de SUDEP.