Spongiform encephalopathy with chronic progressive external ophthalmoplegia

Abstract

Chronic progressive external ophthalmoplegia is a disorder characterized by bilateral ptosis and ocular immobility. In recent years, based primarily on biopsy material, myopathy of the extraocular muscles has been regarded as the cause of this syndrome. A patient with chronic progressive external ophthalmoplegia is reported in which a levator muscle surgical biopsy and the extraocular muscles examined at autopsy showed changes compatible with a myopathy. Yet, examination of the brain revealed a spongiform encephalopathy with involvement of supranuclear, nuclear, and internuclear structures concerned with eye movements. The difficulty in interpreting extraocular muscle pathology is discussed, and it is emphasized that proof of the myopathic origin of chronic progressive external ophthalmoplegia must not rest exclusively with a muscle biopsy.