PET imaging of redox and energy states in stroke-like episodes of MELAS.

In stroke-like episodes of patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), changes in oxidative stress and glucose metabolism and their sequence remain obscure. We developed a novel double imaging method using positron emission tomography (PET) with [(62)Cu]-diacetyl-bis(N4-methylthiosemicarbazone) ((62)Cu-ATSM) and [(18)F]-fluorodeoxyglucose ((18)FDG) to visualize the regional oxidative stress, glucose metabolism and blood flow in brain lesions of stroke-like episodes non-invasively and rapidly. These PET imagings were performed on a MELAS patient with stroke-like lesions, and clearly demonstrated that oxidative stress following hyperemia along with increased glucose metabolism plays crucial roles in the pathogenesis of MELAS stroke-like episodes.