[MELAS: diagnostic keys and treatment in the Intensive Care Unit].

Cerebrovascular accident in young adults is not rare and the most common causes are: cardiac embolism, arterial dissection and migraine. The unknown etiology, in spite of extensive studies, is described in the literature in about one third of patients under 45 years of age. The mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) may occur with symptoms that simulate a stroke. The <<stroke-like>> episodes generally affect the posterior part of the brain and the basic insult mechanisms may be metabolic more than ischemic. We describe the case of an 18-year old patient who was admitted to the Intensive Care Unit due to a sudden picture of blindness. The ophthalmologic study was normal and the neuroimaging studies showed infarction in both occipital lobules. We explain the different clinical features, diagnostic, therapeutic and prognostic methods of the disease.