ObjectiveTo investigate the clinical, imaging and pathological features of mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes syndrome(MELAS).

MethodsThe clinical, imaging and pathological data of 4 cases with MELAS were retrospectively analyzed.

ResultsThere were 1 case of seizure, 2 cases of headache and 1 case of fever complicated with disturbance of consciousness.The results of cranial MRI showed that the parietal, occipital and/or temporal lobes lesions were long or slightly longer T1WI/T2WI and FLAIR hyperintensity, gyri-like changes, and not enhancement.The disappearance or fracture of transverse striations and irregular red edge fibers(RRF) under the muscle membrane were found in 3 cases detected by muscle biopsies.One case with mitochondrial DNA A3243G site mutation was found by routine gene testing, and the muscle biopsy in 1 case was not be done during the multiple hospitalizations.

ConclusionsThe strokelike episodes complicated with seizures, visual and hearing loss, and cognitive impairment are the major performance of MELAS.The imaging features show that the lesions are mainly involved in the posterior cortex of both cerebral hemispheres, and gyri-like changes.The RRF can be found using the muscle biopsy, and the mutations in mitochondrial DNA A3243G can be found using gene testing.