MELAS型线粒体脑肌病的临床、影像学和肌肉病理分析

Analysis on clinic,neuroimaging and myopathological features of MELAS

目的探讨MELAS型线粒体脑肌病的临床表现、影像学特点和肌肉组织病理学改变,提高人们对本病的认识。方法回顾性分析5例MELAS型线粒体脑肌病的临床表现、脑影像学改变(MRI和CT),以及骨骼肌活检的组织病理学特点。结果MELAS型线粒体脑肌病的主要临床表现为局灶性或全身性癫发作、听觉和视觉障碍、运动不能耐受、认知功能障碍、脑卒中样发作、血乳酸水平升高等。脑影像学检查可见病灶多位于颞、枕、顶叶皮层脑回处,脑MRI表现为长T1、长T2信号,部分患者头颅CT可见基底节钙化。骨骼肌活检5例患者肌肉组织中均可见破碎红边纤维(RRF),2例行电镜检查均可见异常线粒体聚集。结论MELAS型线粒体脑肌病是一种以高乳酸血症和卒中样发作为特征的脑和肌肉能量代谢障碍综合征。患者临床表现复杂多样,容易造成误诊,其诊断需在临床表现和影像学特点的基础上,结合骨骼肌活检病理检查发现RRF或异常线粒体聚集,可获得临床确诊。

Objective To investigate the clinic, neuroimaging and myopathological features in the patients with MELAS type of mitoebondrial encephalomyopathy. Methods The clinical manifestation, neuroimaging（MRI and CT）and myopathological features of 5 patients with MELAS were retrospectively analyzed. Results The main clinical features were characterized by focal or generalized seizures, visual disturbance, sensorineural deafness, dementia, stroke-like episodes, lactic acidosis and so on. Neuroimaging showed multiple lesion primarily in gray matter of occipital, parietal, temporal cortex, which was expressed by the abnormal longer T1 and T2-weighted signals on MRI. CT showed calcification in basal ganglia. Muscle biopsy showed red ragged fiber （RRF） in 5 patients. Conclusion MELAS type of mitochondrial encephalomyopathy is a complex disease with disorder of energy metabolism. Stroke-like episodes and lactic acidosis are the prominent symptoms in MELAS. According to clinical manifestations and neuroimaging features, MELAS can be defined in combination with muscle biopsy.