Hypertension and stroke.

HYPERTENSION AND STROKE: Hypertension is a major risk factor for stroke, and stroke prevention is the most important achievement of modern antihypertensive treatment. In controlled trials, a few years of this treatment can eliminate the entire excess stroke risk associated with hypertension. In observational studies, stroke risk appears to be not always fully reversible when the blood pressure is lowered with drugs. Hypertension is associated with an increased incidence of both haemorrhagic, ischaemic and lacunar stroke. It is likely that antihypertensive treatment prevents all these types of strokes as well as transient ischaemic attacks. ACUTE STROKE: In acute stroke, a transient rise in blood pressure is common, in some cases superimposed on chronic hypertension. No major controlled trials have reported findings on whether blood pressure should be lowered acutely in such patients. On the basis of observational studies and haemodynamic considerations, it seems prudent to leave all but the highest blood pressures in acute stroke to settle spontaneously. ISCHAEMIC STROKE: Ischaemic stroke may occasionally be precipitated by overzealous blood pressure reduction. This has been reported in particular in the initial treatment of very severe hypertension, and occasionally in the elderly hypertensive. It may also occur in the rare cases where transient cerebral ischaemia is haemodynamically induced.