MELAS型线粒体脑肌病的临床、病理及影像学研究

目的：探讨线粒体脑肌病中ELAS型的临床、影像学、组织病理学特点及 诊断方法。方法：对4例MELAS患者的临床、影像学（CT、MRI）及组织商理学特点进行系统分析，观察3例患者的肌活检及2例患者的脑活检结果。结果：患者主要临床表现为运动不耐受、发作性头痛和呕吐，局灶或全身性癫痫，认知障碍，脑卒中样发作，神经性耳聋、肥厚性心肌病、内分泌功能紊乱，乳酸水平升高及身材矮小等，肌电图示肌源性改变，脑CT及MRI示病灶多位于枕、顶、颞叶脑回处、CT可见基底节及小脑钙化，肌肉组织可见不整红边纤维（RRF）和异常线粒体，脑活检灰质呈分层性坏死，小血管弥漫增生、星形胶质细胞增生及钙沉积，符合MELAS型诊断，结论：根据MELAS的临床及影像学特点，并结合肌肉及脑组织活检可对该病进行早期诊断。

The studies on clinical manifestations,histopathology and imaging of MELAS

Objective To investigate the clinical manifestions ,neuropathology and imaging in the patients with MELAS type of mitochondrial encephalomyopathy for exploring the diagnostic method of the disease. Methods Systemic study was performed on the clinical features,imaging of four MELAS patients. Muscle biopsy and 2 brain biopsies of 3 cases were examined. Results The main clinical features were characterized by intolerance to exercise,recurrent headache and vomit,focal or generalized seizures,dementia,stroke like episodes,sensorineural deafness, hypertrophic cardiomyopathy,endocrine dysfunction,short stature,lactic acidosis and so on. Electromyography showed myopathic damage. CT showed calcification in basal ganglia. CT showed multiple low density lesion primarily in gray matter of occipital,parietal and temporal cortex,which was expressed by the abnormal longer T 1 and T 2 weighted signals on MRI.Muscle biopsy showed red ragged fiber and abnormal mitochondria. Brain biopsy showed laminar necrosis of cortex,astrocytosis,diffused microvascular proliferation and calcification. Four cases were diagnosed as MELAS type.Conclusion According to clinical manifestations and neuroimage features,MELAS is possibly early defined in combination with muscle or/and brain biopsy.