Diffusion-weighted MR imaging in a case of mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes

In a patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS), both T2- and diffusion-weighted MR imaging revealed lesions as hyperintense areas in the occipital lobes early after strokelike episodes. In these lesions, no significant reduction in apparent diffusion coefficient was noted, Apparent diffusion coefficient mapping ma y help to differentiate strokelike episodes in MELAS from acute ischemic st roke. The strokelike episodes may be related to vasogenic edema and hyperpe rfusion, which were suggested by our single-photon emission CT and MR imagi ng studies.