Mitochondrial encephalomyopathy with sleep apnea.

A rare case with mitochondrial encephalomyopathy, in association with cerebellar ataxia, peripheral neuropathy, mental retardation and alveolar hypoventilation syndrome with sleep apnea, as demonstrated by polysomnography, was encountered. This combination has not been described previously. From a prognostic point of view, alveolar hypoventilation syndrome with sleep apnea is an important clinical feature is this disease entity. Neither ataxia nor the abnormality of pyruvate metabolism was alleviated after 6 months of therapy with coenzyme Q10.