[Hypertensive vascular disease and cerebral microcirculation].

Cerebral microcirculation has a series of complex relationships with arterial hypertension determined, on one hand, by the size and the location of the vessels involved, and on the other hand, by the chronic or acute nature of the hypertension. The small arterial vessels of the cerebral parenchyma react to the effects of chronic hypertension with irreversible structural changes, whose pathologic and radiological correlation is chronic ischemia of the white substance, shown by paleness of the white substance, together with small lacunar infarctions, with a clinical association of dementia, motor disorders and pseudo-bulbar syndrome. With the appearance of an acute rise in arterial pressure, these vessels react with generally reversible changes which lead to an increase in the permeability of the hematoencephalic barrier with formation of cerebral edema and a clinical association generally demonstrating the focal nature of the vascular abnormality (such as in hypertensive encephalopathy with changes in posterior hemispheric predominance) or its unilateral location in cases in which the process occurs in one of the carotid territories (post-endarterectomy).