CPEO and carnitine deficiency overlapping in MELAS syndrome

Mitochondrial myopathy, encephalopathy with lactic acidosis and stroke‐like episodes (MELAS) syndrome is one of the mitochondrial encephalomyopathies that has distinct clinical features including stroke‐like episodes with migraine‐like headache, nausea, vomiting, encephalopathy and lactic acidosis. We report a 27‐year‐old woman who presented with partial seizure, stroke‐like episodes including hemiparesis, hemianopia and hemihypethesia, sensorineural hearing loss, migraine‐like headache, and lactic acidosis. Brain computed tomographic scan showed encephalomalacia in the right parieto‐occipital area and recent hypodensity in the left temporoparieto‐occipital area with cortical atrophy. Muscle biopsy revealed ragged‐red fibers and paracrystaline inclusions in the mitochondria. Genetic study revealed an A to G point mutation at nucleotide position (np) 3243 of mitochondrial DNA. External ophthalmoplegia and ptosis were also found during two exaggerated episodes in this patient. Therefore, the overlapping syndrome of chronic progressive external ophthalmoplegia in the MELAS syndrome is considered in this case. Furthermore, we also found carnitine deficiency in this patient and she was responsive well to steroid therapy. Muscle biopsy also revealed excessive lipid droplets deposits. Therefore, the carnitine defiency may occur in MELAS syndrome with the A to G point mutation at np 3243. We recommend the steroid or carnitine supplement therapy be applied to the MELAS syndrome with carnitine deficiency.