摘要目的：探讨线粒体脑肌病伴乳酸血症和卒中样发作（ MELAS ）患者的临床表现规律。方法回顾性分析1997—2015年来我院就诊的190例MELAS患者的临床资料，其中175例检测到线粒体DNA致病性突变，余15例通过肌肉活体组织检查确诊。统计卒中样发作的各种诱发因素、患者的首发表现以及不同临床表现的出现频率。结果入组患者男女比例为1.44∶1，中位数发病年龄为14岁（7个月～45岁），发病年龄高峰在8～12岁。首次卒中样发作的中位数年龄为16岁（1～53岁），46.15％（66／143）的患者发作前有诱因，劳累（37.88％，25／66）和上呼吸道感染（34.85％，23／66）最常见，其他诱因包括情绪激动、饮酒、外伤、停用抗癫痫药、受惊吓、饱食、饥饿等。卒中样发作占首发表现的70.53％（134／190），随疾病的发展可出现在所有患者中。神经系统症状包括癫痫发作89.42％（169／189）、智能发育迟滞或痴呆82.87％（150／181）、头痛74.30％（133／179）、偏盲或皮质盲67.72％（107／158）、运动不耐受50.87％（88／173）、偏瘫或偏身麻木47.44％（74／156）、感音神经性耳聋46.20％（85／184）、各种类型的失语39.47％（60／152）、精神行为异常17.71％（31／175）、眼外肌瘫痪9.60％（17／177）。非神经系统症状包括多毛67.57％（100／148）、呕吐65.58％（101／154）、发热62.07％（90／145）、身材矮小45.32％（63／139）、腹泻或便秘43.48％（70／161）、低体重指数26.62％（37／139）、糖尿病20.79％（37／178）和肾脏损害3.16％（6／190）。结论该组MELAS患者发病多在儿童期，男性多见，常见症状依次为癫痫发作、智能发育迟滞或痴呆、头痛、皮质盲、多毛、呕吐和发热。

abstractsObjective To summarize the clinical features of Chinese patients with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes ( MELAS).Methods A total of 190 patients with MELAS who presented to Peking University First Hospital between 1997 and 2015 were recruited.Among 190 patients, 175 were identified carrying mitochondrial DNA mutations, and the remaining 15 patients were diagnosed by muscle biopsy.The clinical features, including predisposing factors of stroke-like episodes, the onset symptoms and frequencies of various manifestations were analyzed and reported.Results In our cohort of MELAS patients, the male-to-female ratio was 1.44∶1.The median age of onset was 14 years ( from 7 months to 45 years).The peak onset ages were 8-12 years.The median onset age of the first stroke-like episode was 16 years ( from 1 to 53 years ).There were 66 ( 46.15%) patients who had predisposing factors before the onset, and fatigue and upper respiratory tract infection were the most common predisposing factors of stroke-like episodes in these patients ( 37.88%, 25/66 and 34.85%, 23/66, respectively).Other predisposing factors included emotional agitation, drinking alcohol, trauma, withdrawal of antiepileptic drugs, being frightened, satiation and hunger.Stroke-like episodes appeared in 70.53%(134/190) patients as an onset symptom and developed in all patients with disease progression.The neurological manifestations included seizure ( 89.42%, 169/189 ) , mental retardation or dementia (82.87%, 150/181), headache (74.30%, 133/179), hemianopia or cortical blindness (67.72%, 107/158), exercise intolerance (50.87%, 88/173), hemiplegia or hemianesthesia (47.44%, 74/156), sensorineural deafness (46.20%, 85/184), aphasia (39.47%, 60/152), behaviour disorder (17.71%, 31/175) and ophthalmoplegia ( 9.60%, 17/177 ).The manifestations of extra-nervous systems included hirsutism (67.57%, 100/148), vomiting (65.58%, 101/154), fever (62.07%, 90/145), short stature (45.32%, 63/139), diarrhea or constipation (43.48%, 70/161), low body mass index (26.62%, 37/139), diabetes mellitus (20.79%, 37/178) and kidney disease (3.16%, 6/190).Conclusions The majority of the patients in this study have the disease onset during childhood.There are more male MELAS patients than females.Most common clinical manifestations are seizure, mental retardation or dementia, headache, cortical blindness, hirsutism, vomiting and fever in this patient group.