Hypertension and vascular dementia.

Postmortem surveys on patients treated for chronic hypertension often fail to demonstrate significant vessel changes. Nevertheless, hypertensive alterations in the brain can include infarcts and hemorrhages. Autopsies in a primary care hospital have shown that hypertension can affect arteries, arterioles, and capillaries in various patterns and degrees in the brain. These vascular lesions may be associated with large and small infarcts and hemorrhages in isolated or diffuse patterns. Widespread cerebral edema can occur with rapidly progressive hypertension. Atherosclerosis, arterial and arteriolar fibrinoid necrosis, and micro-aneurysms may be observed. Chronic hypertensive encephalopathy causes vascular dementia and can be associated with subcortical arterial and arteriolar leukoencephalopathy, leukoaraiosis and/or Binswanger's disease. Epidemiologic evaluations based on complete autopsy studies need to be correlated with compliance of therapy, appropriate diagnosis of hypertension, and its long-term effects on the nervous system. Although persistent poorly controlled hypertension is known to damage the brain both acutely and chronically, the effects of intermittent hypertension remain to be defined.