MELAS syndrome is classically presented as a mitochondrial encephalopathy complicated by lactic acidosis and recurrent strokes. However, this rare disease can have a more atypical presentation, as in the following observation reported by a Chinese team:
- a 17 year old girl with no previous history of herpes had a clinical picture that initially suggested herpetic encephalopathy;
- the combination of a febrile syndrome, disturbance of consciousness and compatible images on brain imaging could have been suggestive;
- the non-response to antiviral treatment, atypia on imaging and the persistence of lactic acidosis in the blood raised doubts about the initial diagnosis;
- the diagnosis of MELAS was finally confirmed by molecular biology (3243 A>G mutation).
