Clinical features and SCN1A gene mutation analysis of severe myoclonic epilepsy of infancy

目的 探讨婴儿严重肌阵挛癫癎(SMEI)的临床特点和基因诊断.方法分析13例SMEI患儿的临床和脑电图(EEG)特点及钠离子通道SCN1A基因突变筛查结果.结果男10例,女3例.8例有热性惊厥和癫痫家族史.惊厥起病年龄2～9个月,平均5.6个月.首次发作为热性惊厥9例.13例在病程早期均以反复发热诱发的全面性或一侧性阵挛或强直阵挛发作为主,其中8例有热性惊厥持续状态.出现无热惊厥的年龄为2～21个月.病程中均出现多种发作类型.发作均有热敏感的特点,诱发因素包括发热、洗热水澡和疫苗接种.起病后出现智力发育落后11例.共济失调5例,锥体束征阳性2例.EEG在1岁前多数正常,1岁后出现全导或局灶放电.头颅MBI检查异常2例.13例均应用多种抗癫痫药治疗,发作均未完全控制.卡马西平和拉莫三嗪使部分患儿发作加重.10例发现有SCN1A基因突变.结论 SMEI的临床特点是:1岁以内起病,首次发作常为热性惊厥;1岁以后出现多种发作形式和智力发育落后;发作具有热敏感的特点;EEG早期正常,以后出现全导或局灶放电.筛查SCN1A基因突变有助于早期明确诊断,指导选择抗癫癎药物.Objective Severe myoclonic epilepsy of infancy (SMEI),or Dravet syndrome,is a severe epileptic encephalopathy.This study aimed to investigate the clinical features and genetic diagnosis of SMEI.Methods The electroclinical data and the mutation of SCN1A gene in 13 children with SMEI were analyzed.Results Of the 13 children,10 were males and 3 were females.Eight of them had family history of febrile seizures.The average age of seizure onset was 5.6 months,with a range of 2 to 9 months.The initial seizure was a febrile seizure in 9 patients (69%).Generalized or hemiclonic seizures were often triggered by fever.Eight patients had a history of febrile status.Mebrile seizures occurred from 2 months to 21 months of age.All patients went on to develop multipie seizure types.Generalized tonic clonus seizures (GTCS) were found in 11,partial seizures in 12,atypical absence in 10.Myoclonic seizures were presented in all patients.Twelve patients had 3 or more seizure types.Seizures of all patients had a characteristic of temperature sensitivity.The precipitaring factors included fever,hot bath and vaccination.Nine patients (69%) had a history of status epilepticus.Delay in mental development was present in 11 cases,ataxia in 5 and pyramidal sign in 2.EEG was normal in most patients in the first year of life,followed by generalized,focal and multifocal discbarges.Brain MRI wag abnormal in 2 cages.Seizures were not completely controlled in all patients.Carbamazepine and lamotrigine ne aggravated seizures in some patients.SCN1A gene mutation wag found in 10 cases,including seven missense mutations,two nonsense mutations and one frame shift mutation.Conclusion The clinical features of SMEI were seizure onset within one year of age,first event is often a febrile seizure;multiple seizure types and mental delay occurred after the second year of life:seizures have a characteristic of temperature sensitivity;EEG was normal in the first year of life,folowed by generalized,focal or muhifocal discharges;early diagnosis by testing SCN1A mutation guides selection of antiepileptic drugs.北京市自然科学基金中文核心期刊要目总览(PKU)中国科技核心期刊(ISTIC)中国科学引文数据库(CSCD)010769-7734