Circulatory Reflexes in Patients with Cerebrovascular Disease

THE role of systemic hypotension in the genesis of local cerebral ischemia is not clear. Denny-Brown and Meyer1 and Denny-Brown2 have shown that a temporary fall in systemic blood pressure can produce a significant reduction in blood flow in a diseased part of the vascular tree supplying the brain, leading to the so-called hemodynamic crisis, and suggested this to be a cause of transient ischemic attacks. However, hypotension induced by tilting to the vertical plane2 3 4 or by the use of ganglion-blocking drugs5 was not associated with transient symptoms due to local ischemia in patients with cerebrovascular disease.Smirk and Hodge . . .