Perhexiline neuropathy: a clinicopathological study.

Five patients developed a mild to severe polyneuropathy while under treatment with perhexiline maleate, a drug used in long-term treatment of angina pectoris. Recovery took place within a few months after drug withdrawal. We performed qualitative and quantitative light and electron microscopical studies, including teased fiber preparations, in different patients; 16 to 90% of the fibers showed segmental demyelination, an unusual feature in drug-induced neuropathies, and 3 to 20% were undergoing wallerian degeneration. Severe loss of myelinated axons was noted in all 5 patients. In these patients clinical symptoms occurred only when a great number of fibers had already been lost and most of the surviving fibers showed demyelination.