Vascular involvement in a patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes.

A 26-year-old man with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) was admitted to our hospital for further cardiovascular examination. A muscle biopsy demonstrated strongly succinate dehydrogenase-reactive blood vessels. Pulse wave contour analysis revealed that both capacitive and oscillatory compliance were markedly reduced in this patient compared with 45 normal age-matched control subjects. Hepatocyte growth factor was remarkably elevated in this patient over that of 10 normal control subjects. These findings suggest that a MELAS patient has not only pathologic but also functional vascular involvement. If so, patients with MELAS need systemic vascular assessment.