Background: Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) is a progressive maternally inherited multi-organ disorder caused by a mutation in a mitochondrial gene. In this disorder recurrent migraine headache, seizure, cerebral insults causing hemiparesis, hemianopia, progressive hearing loss and cognitive problems may occur.

Case presentation: The patient is a 12-year girl manifested with malaise, tonic-clonic convulsion and unilateral weakness in left upper and lower extremities. Her problem was begun with seizure, headache and recurrent vomiting, 5 months before the admission. On clinical examination cerebrovascular events was diagnosed. On broader diagnostic studies, also a genetic mutation in A3243G gene, as a definite characteristic for the establishment of the disease, was detected by muscle biopsy.

Conclusion: Patients suffering from the syndrome gradually display delayed motor and cognitive development. Therapeutic management of the disease consists of administration of multi-vitamins and coenzyme supplementations, and lowering the serum lactate level using dichloroacetate.