ABSTRACT
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.