Effect of reducing elevated blood pressure on cerebral circulation.

Abstract

Circulation to the brain is protected not only by autoregulation, which maintains cerebral blood flow (CBF) in spite of a decrease in mean arterial pressure, but also by baroreflexes that tend to prevent or minimize hypotension. Hypertensive patients have impaired cerebral autoregulation and depressed baroreflex sensitivity, suggesting that the brain might be vulnerable to a reduction in blood pressure. Nevertheless, in clinical experience, studies of cerebral blood flow during drug-induced reduction of elevated blood pressure have shown that control of hypertension can usually be achieved without jeopardizing cerebral blood flow or inducing signs and symptoms of cerebral ischemia, even in patients with cerebrovascular disease. Indeed, control of hypertension reduces both the risk of stroke and the recurrence rate for second strokes.