Hypertension and the brain.

The brain plays an important role in the short-term regulation of blood pressure via sympathetic and parasympathetic mechanisms as well as other neurohumoral pathways including the hypothalamo-pituitary axis. The role of the central nervous system in long-term blood pressure control is less well defined but centrally mediated increased sympathetic activity has been identified in the spontaneously hypertensive rat. In addition to the role of the brain in the control of blood pressure and mechanisms of hypertension, there are important effects of blood pressure on brain function. Hypertension is a major risk factor for cerebrovascular disease and stroke. Effective antihypertensive treatment can reduce the relative risk of stroke by up to 40% and control of blood pressure appears to prevent both atherothrombotic and haemorrhagic stroke.