中文摘要：

目的 总结Dravet综合征（DS）患儿发生癫痫持续状态导致的急性脑病的临床和头颅影像学特点.方法 回顾性收集2005年2月至2016年8月在北京大学第一医院儿科就诊的DS患儿的临床资料并筛查SCN1A基因突变,对发生癫痫持续状态后出现急性脑病（昏迷≥24 h）的DS患儿进行随访,总结其临床及头颅影像学表现.结果 共随访412例DS患儿,其中22例（男9例、女13例）发生急性脑病.发生急性脑病的22例患儿中SCN1A基因突变阳性者18例,阴性者4例;发生急性脑病时的年龄为6月龄～ 10岁;抽搐持续时间为40 min ～9 h,其中21例发病前有高热,1例体温正常;发作后昏迷持续2～20 d.发生急性脑病后9例死亡,13例出现严重智力、运动倒退;13例存活的患儿末次随访距离急性脑病发生中位时间为2年3个月（7个月～4年4个月）,9例患儿在大运动、反应或语言方面有不同程度的恢复,4例无明显好转;癫痫发作与出现急性脑病之前比较,6例未再出现发作,4例发作减少,3例无明显差异,其中2例出现痉挛发作.6例患儿可获得急性期头颅磁共振成像（MRI）结果,提示双侧（2例）或一侧（4例）大脑半球弥漫性肿胀,其中2例伴大脑皮层下白质长T1长T2信号;13例存活的患儿恢复期头颅MRI均提示不同程度的大脑皮层萎缩,其中4例伴小脑萎缩,1例伴右侧脑桥萎缩,4例伴皮层下或侧脑室旁白质异常信号,2例伴右侧海马硬化,1例伴双侧基底节异常信号.结论 DS患儿在病程中出现高热时易发生癫痫持续状态,严重者可导致急性脑病甚至死亡,存活者可遗留神经系统后遗症.头颅MRI急性期表现为脑水肿,恢复期表现为不同程度的大脑皮层萎缩,少数可伴小脑、脑桥萎缩,海马硬化或白质、基底节异常信号.

英文摘要：

Objective To investigate the clinical and neuroimaging characteristics of acute encephalopathy （AE） after status epilepticus （SE） of patients with Dravet syndrome （DS）.Method The clinical data of DS patients who had AE （coma ≥24 h）.after SE were retrospectively collected from February 2005 to August 2016 in Peking University First Hospital and SCN1A gene tests were performed.The clinical and neuroimaging features were summarized.Result Twenty-two patients （9 males and 13 females） with AE were collected among 412 DS patients during follow-up.Of which 18 patients had SCN1A gene mutations while the remaining 4 patients had no SCN1A gene mutations.The onset age of AE was between 6 months and 10 years.The duration of SE varied between 40 minutes and 9 hours.Prior to the onset of SE,twenty-one patients had high fever,and one patient had normal temperature.Coma lasted from 2 days to 20 days.Nine patients died after the AE,and 13 patients survived with massive neurological regression.From AE to the last visit,the median time of follow-up was 2 years and 3 months （from 7 months to 4 years and 4 months）.Nine of 13 survivors had varied improvement in motor,language and cognition,while the remaining 4 patients had no significant improvement.After AE,there were 6 patients with seizure-free,4 patients with reduced seizures,and 3 patients with no change in seizure frequency,moreover,spasm occurred in 2 patients.Six patients had brain magnetic resonance imaging （MRI） in acute phase and showed bilateral （2 patients） or unilateral （4 patients） hemisphere edema,accompanied by subcortical white matter hyperintense signal in T1 and T2 weighted images in two patients.The neuroimaging of 13 survivors demonstrated diverse cortical atrophy during recovery phase,among which 4 patients showed cerebellar atrophy,one patient had right pontine atrophy,4 patients accompanied by signal abnormalities in subcortical and periventricular white matter,2 patients showed right hippocampal sclerosis,and one patient