Progressive external ophthalmoplegia and myositis.

We reported a senile male patient with progressive external ophthalmoplegia (PEO) and myositis. The ophthalmoplegia was severe, but other neuromuscular features were nearly normal. Muscle enzymes in serum were moderately elevated. Autoimmune, endocrinological or malignant diseases were not observed during the previous 4 years. Pathology of non-weak limb muscles biopsied twice was consistent with active inflammatory myopathy. The ragged-red or cytochrome c oxidase-negative fibers, which are a hallmark of mitochondrial myopathy with PEO, were not increased in comparison with age-matched control muscles. Analysis of mitochondrial DNA in muscle by the Southern blot method did not reveal any deletions. It was concluded that the inflammatory myopathy, myositis clinically localized at the ocular muscles, is an important and distinct disorder in PEO.