CT, MRI, and autopsy findings in brain of a patient with MELAS.

Brain autopsy findings in a 14-year-old patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes were compared with those of computed tomography (CT) and magnetic resonance imaging (MRI). Pathologic examinations revealed extensive laminar necrosis bordered by gliotic tissues throughout the cerebral cortices. Moderate losses of myelin and fibrous gliosis were also observed in the subcortical and deep white matter. These lesions were demonstrated as low-density areas on CT and as high-signal areas on T2-weighted MRI. MRI revealed the lesions more distinctively and precisely than CT. Neither CT nor MRI could reveal abnormalities in the basal ganglia, including vascular proliferation and calcium deposits in the blood vessels.