[Disrupted circle of Willis and crisis course of arterial hypertension].

Two patients, aged 17 and 55 years, with partly or completely open circle of Willis were examined using cerebral magnetic resonance angiography. A role of anatomical structure of circle of Willis and other anastomotic peculiarities of brain blood supply in cerebral vascular crises development is demonstrated. The latter can proceed as hypertensive ones on the background of emotional overloading and also reflect other features of brain blood supply in its clinical picture e.g. an absence of one of spinal arteries on the background of atherosclerosis and arterial hypertension.