[Mitochondrial encephalomyopathy, lactic acidosis and features of cerebrovascular disorders].

A 12 year old girl with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke like episodes (MELAS) is reported. After a normal childhood, at 9 years of age she developed generalized and hemilateralized seizures. Posteriorly, these episodes became more frequent and were accompanied by headache, homonimous hemianopsia, ataxia, vomiting, photophobia, left hemiparesis, slurred speech and even convulsive status. Laboratory tests evidenced lactic acidosis, brain lucencies at CT Scan and ragged skeletal muscle fibers at muscle biopsy.