[Experimental data on the pathogenesis of hypertensive encephalopathy].

Experimental investigations of the pial vessels during acutely drug-induced hypertension revealed diffuse or sausage-like distension of arterioles. Degree and type of reactions depended on blood pressure characteristics like steepness of increase, percentual increase, duration and peak value in this order. Such vasodistension is interpreted as mechanical overwhelming of smooth muscle force within the arteriolar wall during acute increase of intraluminal pressure. Clinical consequences of these results are: Vasodilators as well as sedatives with respiratory depression are contraindicated for patients with hypertensive crises. Data also make readily apparent, that short lasting acute hypertension may be fatal for patients with preexisting disturbances of blood-brain barrier function as it accelerates the development of brain edema.