Abstract: Objective　To analyze and summarize the clinical manifestations, diagnosis, and treatment principles of children with mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). Methods　The clinical data of 2 cases of MELAS syndrome in Department of Pediatric Neurology, Affiliated Hospital of Binzhou Medical University were summarized, and the relevant literatures at home and abroad were reviewed. Results　Case 1 was a 12-year-old female with clinical symptoms such as apoplexy attack, epileptic attack, intractable headache, vomiting, poor exercise endurance, short stature, and hairy back. Occipital lobe lesions were observed in head MRI, lactic acid level was significantly increased in blood biochemistry and cerebrospinal fluid, and m.3243A>G mutation of the MT-TL1 gene was found in the girl and her mother's genes. Case 2 was a 5-year-old female with clinical symptoms such as seizures, short stature, and hairiness. The blood lactic acid was significantly increased, the myocardial enzyme spectrum was abnormal, and m.3243A>G mutation of the MT-TL1 gene was found by the mitochondrial gene detection. Two cases were clearly diagnosed as MELAS syndrome. Through clinical practice combined with relevant literatures, the treatment plan and drug dosage for the two children were further clarified, and they were being followed up. Conclusions　Mastering the clinical features of MELAS syndrome can help us find the basis for diagnosis more quickly and effectively. Through the review of related literatures, we further clarify the pathogenesis, selection plans for auxiliary examination, diagnosis basis, and treatment principles of MELAS syndrome.

Key words: Children, MELAS syndrome, Diagnosis and treatment experiences

摘要： 目的　分析及总结线粒体脑肌病伴高乳酸血症和卒中样发作（MELAS）患儿的临床表现、诊断及治疗原则。方法　总结滨州医学院附属医院儿童神经科临床诊治的2例MELAS综合征患儿病例资料，查阅及复习中外相关文献。结果　病例1，女，12岁，临床表现为卒中样发作、癫痫发作、顽固性头痛、呕吐、运动耐力差、身材矮小、背部多毛等症状；头颅磁共振可见枕叶病变，血生化及脑脊液可见乳酸水平明显升高；患儿及其母线粒体基因检测发现MT-TL1基因的m.3243A>G变异。病例2，女，5岁，患儿有癫痫发作、身材矮小、多毛，且血乳酸明显增高、心肌酶谱异常，线粒体基因检测发现MT-TL1基因的m.3243A>G变异。2例均明确诊断为MELAS综合征。通过临床实践并结合相关文献，进一步明确2例患儿的治疗方案及药物用量，目前正在随访中。结论　掌握MELAS综合征的临床特点能更快速有效找到诊断依据，通过文献复习进一步明确了MELAS综合征的发病机制、辅助检查的选择方案、诊断依据及治疗原则。

关键词: 儿童, MELAS综合征, 诊治体会