线粒体脑肌病伴高乳酸血症和卒中样发作的诊断

目的 分析总结线粒体脑肌病伴高乳酸血症和卒中样发作(MELAS)的临床表现和辅助检查结果,探讨在MELAS诊断中存在的问题,提出MELAS早期临床诊断的可行性.方法 归纳总结34例MELAS患者的临床表现,寻找对MELAS患者相对特异的症状组合.同时总结分析各项辅助检查结果,结合文献复习解读血和脑脊液的乳酸水平、神经影像、肌肉活体组织检查(活检)和基因检查对于MELAS诊断的意义和局限性.结果 本组患者最常见的临床表现依次为:癫癎发作、头痛、智能下降、卒中样发作、发育异常、四肢无力和易疲劳、眼肌麻痹.血空腹乳酸或运动后乳酸升高23例(67.6%).32例头颅MRI异常的患者最常见的受累部位依次为枕叶、顶叶、颞叶、基底节、额叶、小脑和深部白质.32例患者行肌肉活检,有阳性发现的共24例(75%),阴性的8例(25%).14例患者行基因检查,9例发现A3243G位点突变,5例未发现该位点突变.结论 认识MELAS的各种临床表现,争取在卒中样发作出现前早期诊断是完全可行的.

Diagnosis of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes

Objective The clinical,laboratory,and neuroradiologic features of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) were analyzed and early clinical diagnosis was proposed.Method The various presentations of 34 MELAS patients were summarized to identify the specific symptoms and signs.The appropriate interpretation of the ancillary examinations,including lactic acid levels of blood and cerebral spinal fluid,neuroradiology,muscle biopsy and genetic test,was emphasized.the diagnostic significance and limitations of clinical,laboratory and neuroradiologic features were pointed out.Result The most common clinical presentations were listed in order of frequency:seizures,headache,mental decline,stroke-like episode,development abnormality,muscle weakness,fatigue,and ophthalmoplegia.Raised fasting or post-exercise blood lactic acid levels were found in 23 patients (67.6%).The most common lesions were located in the occipital lobe,parietal lobe,temporal lobe,basal ganglion,frontal lobe,cerebellum and deep white matter of 32 patients.Ragged red fibers were found in 24 patients (75%),and 8 other patients had negative muscle biopsy.Fourteen patients underwent genetic test,of which 9 patients had point mutation at 3243.Conclusion It is feasible to have early recognition of the various presentations of MELAS and make an early diagnosis even before the stroke like episodes.