Chronic pain after methysergide: a new cause of ischemic monomelic neuropathy.

Chronic foot pain developed in a 43-year-old woman after taking methysergide, a potent vasoconstrictor. The etiology was believed to be ischemic monomelic neuropathy, which results from the compromise of blood flow to an extremity. The patient eventually required a surgical sympathectomy after lumbar sympathetic blocks failed to provide permanent relief.