Abstract

A male with mitochondrial myopathy, encephalopathy, lactic acidemia, and strokelike episodes is reported. He had also recurrent episodes of ileus. Muscle biopsy revealed ragged-red fibres. The cytochemistry of cytochrome c oxidase (CCO) showed scattered nonstained fibres, while all muscle fibres were heavily stained by immunocytochemistry using CCO antibody. These findings suggest that partical CCO deficiency may be present in the skeletal muscles of the patient. NADH cytochrome c reductase in the patient's muscle mitochondria was low compared with normal controls (about 26%), although succinate cytochrome c reductase was normal. Coenzyme Q10 administration (90 mg/day) did not improve CSF lactate levels, but did decrease plasma lactate levels. His muscle weakness slightly improved.