What are pathological consequences of HTN for brain?

• Stroke is the second most frequent cause of death in the world • Elevated blood pressure is the strongest risk factor for stroke • Treatment of hypertension decreases the incidence of both ischemic and hemorrhagic stroke • Cerebral blood flow remains unchanged over a wide range of arterial pressures (mean arterial pressure of 50- 150 mmHg) through a process termed autoregulation of blood flow • In patients with the clinical syndrome of malignant hypertension encephalopathy is related to failure of autoregulation of cerebral blood flow at the upper pressure limit， resulting in vasodilation and hyperperfusion.