Chronic progressive external ophthalmoplegia (CPEO) with 'ragged red fibers'--a case report.

Chronic progressive external ophthalmoplegia (CPEO) is a rare clinical syndrome characterized by slowly progressive paralysis of extraocular muscles. We report a male patient who had a 20 year history of CPEO. Histological examination of left deltoid muscle showed characteristic ragged red fibers. Electron microscopy revealed a number of abnormal mitochondria which contain paracrystalline inclusion bodies.