Double-blind trial of oral papaverine in chronic cerebrovascular ischemia.

A preliminary analysis of the effect of long-term therapy with oral papaverine has been made in 11 patients with chronic cerebral ischemia due to cerebral arteriosclerosis. The cases were classified as remote cerebral infarction (6 patients) or vertebrobasilar arterial insufficiency (5 patients). The patients received 225 mg or 450 mg daily, assigned in a double-blind manner. Most showed clinical improvement and improvement on the EEG. There was a statistically significant increase in regional cerebral blood flow in the vertebrobasilar arterial distribution, including the brain stem and cerebellar and posterior cerebral regions, particularly in the right hemisphere. Evidence appears to indicate that zones of severe remote cerebral infarction are refractory to pharmacologically induced vasodilation.