Zhang Yue-hua, Sun Hui-hui, Liu Xiao-yan, Ma Xiu-wei, Yang Zhi-xian, Xiong Hui, Qin Jiong, Lin Qing, Wu Xi-ru
Department of Pediatrics, First Hospital, Peking University, Beijing 100034, China.
Zhonghua Er Ke Za Zhi. 2008 Oct;46(10):769-73.
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.
The electroclinical data and the mutation of SCN1A gene in 13 children with SMEI were analyzed.
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. Afebrile seizures occurred from 2 months to 21 months of age. All patients went on to develop multiple 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 precipitating 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 discharges. Brain MRI was abnormal in 2 cases. Seizures were not completely controlled in all patients. Carbamazepine and lamotrigine aggravated seizures in some patients. SCN1A gene mutation was found in 10 cases, including seven missense mutations, two nonsense mutations and one frame shift mutation.
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, followed by generalized, focal or multifocal discharges; early diagnosis by testing SCN1A mutation guides selection of antiepileptic drugs.
婴儿严重肌阵挛癫痫（SMEI），即德雷维特综合征，是一种严重的癫痫性脑病。本研究旨在探讨SMEI的临床特征及基因诊断。
分析13例SMEI患儿的临床电生理资料及SCN1A基因突变情况。
13例患儿中，男10例，女3例。其中8例有热性惊厥家族史。癫痫发作平均起病年龄为5.6个月，范围为2至9个月。9例患者（69%）首发为热性惊厥。全身性或半侧阵挛性发作常由发热诱发。8例有热性惊厥持续状态病史。无热惊厥发生于2个月至21个月龄。所有患者均继而发展为多种发作类型。11例出现全身性强直阵挛发作（GTCS），12例出现部分性发作，10例出现不典型失神发作。所有患者均有肌阵挛发作。12例患者有3种或更多发作类型。所有患者的发作均有温度敏感性特征。诱发因素包括发热、热水浴和疫苗接种。9例患者（69%）有癫痫持续状态病史。11例存在智力发育迟缓，5例有共济失调，2例有锥体束征。大多数患者在出生后第一年脑电图正常，随后出现全身性、局灶性和多灶性放电。2例脑MRI异常。并非所有患者的癫痫发作都得到完全控制。卡马西平和拉莫三嗪在部分患者中加重了癫痫发作。10例发现SCN1A基因突变，包括7个错义突变、2个无义突变和1个移码突变。
SMEI的临床特征为1岁内起病，首发常为热性惊厥；1岁后出现多种发作类型及智力发育迟缓；发作具有温度敏感性特征；出生后第一年脑电图正常，随后出现全身性、局灶性或多灶性放电；通过检测SCN1A基因突变进行早期诊断有助于指导抗癫痫药物的选择。
