Abstract:

This study aims to investigate the clinical manifestations, laboratory and imaging features, pathological and genetic testing, diagnosis and treatment in 3 children patients with mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS). Focal refractory epileptic seizures were the main clinical manifestations of 3 children, at the same time with stroke-like episodes, exercise intolerance, short stature, paroxysmal headache, vomiting, cognitive impairment, visual impairment, increased blood lactic acid (LA) level and metabolic acidosis. Head MRI showed the lesions were located in temporo-parieto-occipital lobes, and EEG showed slow-wave background, bilateral asymmetry and interictal epileptiform discharges of occiput. Mitochondrial DNA (mtDNA) A3243G mutation was found in the peripheral blood samples of 2 cases. The mutation was not detected in the other case, however, the muscle biopsy revealed pathological changes of mitochondrial myopathy. All 3 cases were treated by antiepileptic drugs (AEDs) including topiramate, levetiracetam and oxcarbazepine, and cocktail therapy. One case died of status epilepticus (SE) after 46 months of follow-up, one case had stroke-like episodes for 2-3 times per year during the follow-up of 40 months, and one case was lost. The clinical manifestations, laboratory and imaging characteristics, pathological and genetic testing in children of MELAS have certain features, which will be helpful for early identification and definite diagnosis, and thus may reduce misdiagnosis and mistreatment.

Key words: MELAS syndrome, Child

摘要：

回顾分析3 例线粒体脑肌病伴乳酸血症和卒中样发作（MELAS）患儿的临床表现、实验室和影像学特点、病理学和基因检测、诊断与治疗过程。3 例患儿均以局灶性难治性癫痫发作为主要临床表现，同时伴脑卒中样发作、运动不耐受、身材矮小、发作性头痛和呕吐、认知功能障碍、视觉障碍、血清乳酸水平升高、代谢性酸中毒等；头部MRI 显示病灶多位于颞顶枕叶；脑电图呈现背景慢波，双侧不对称、发作间期可见后头部样放电，其中2 例外周血标本检测到线粒体DNA A3243G 点突变，1 例未检测到基因突变但肌肉组织活检符合线粒体肌病病理改变；均予托吡酯、左乙拉西坦、奥卡西平口服抗癫痫治疗，鸡尾酒疗法对症支持治疗；1 例随访46 个月，死于癫痫持续状态，1 例随访40 个月，脑卒中样发作2 ~ 3 次/年，1 例失访。提示应结合临床表现、实验室和影像学特点、病理学和基因检测早期和准确诊断MELAS综合征，以减少误诊和误治。

关键词: MELAS综合征, 儿童