A sonographic examination of the arteries feeding the brain can identify the presence of deposits and calcifications. These arise in older and younger people. Among the vascular risk factors are smoking, high cholesterol, high blood pressure, diabetes or a hereditary predisposition. Circulatory disturbances can result from constrictions equal to or greater than 75%, particularly if those constrictions or vascular occlusions are present on both sides. Drug treatment is used in the majority of cases, with typically aspirin, cholesterol-lowering drugs (statins) and anti-hypertensive drugs being used. It is rare that the arteries need to be widened by surgery or using stents.