This article is devoted to the studying of blood flow in cerebral arteries and endothelial function at various stages of chronic cerebral ischemia in cerebral atherosclerosis. While reducing the linear velocity of blood flow, ultrasound scans showed a reduction of visco-elastic properties of the aorta and endothelial dysfunction in large muscular arteries, which correlated with the thickness of the intima-media of the carotid arteries. The data obtained show the reduction of linear blood flow velocity in ultrasonic scanning and the reduction of visco-elastic properties of the aorta, as well as endothelial dysfunction in large muscular arteries. It was found that the most sensitive among the parameters studied in atherosclerosis of the arteries of the brain is a phase shift in occlusive sample. It is determined by the influence of nitric oxide on the smooth muscle cells of the arterial wall of large muscular arteries. It is possible a pharmacological correction of endothelial dysfunction in the large vessels of muscular type of atherosclerosis in patients with chronic cerebral ischemia.