Cerebrovascular aspects of antihypertensive treatment.

Although the treatment of hypertension clearly benefits the brain in most patients, there are, however, unfortunate exceptions. Overzealous blood pressure lowering especially, and sometimes conservative blood pressure lowering, occasionally compromise the supply of blood to the brain to such an extent that neurological dysfunction or death results. Despite an awareness of this problem for more than a decade, the number of reports of such cases is increasing. An understanding of the problem requires detailed knowledge of both the pathophysiology of the cerebral circulation in hypertension and the cerebrovascular effects of antihypertensive drugs. If antihypertensive treatment, in particular emergency blood pressure lowering, is to always be safe, thought must be given to the cerebrovascular effects of the drugs to be used. This topic is discussed in relation to the observed (i.e., experimentally determined) and inferred (i.e., from clinical observation) effects of antihypertensive drugs and treatment on the cerebral circulation, especially with regard to autoregulation of cerebral blood flow.