Carotid Artery Stenosis (CAS)
Carotid artery stenosis (CAS) is a narrowing in the large arteries located on each side of the neck that carry blood to the head, face and brain. The narrowing usually results from atherosclerosis, or a build-up of plaque on the inside of the arteries. Over time, stenosis can advance to complete blockage of the artery.
Risk factors for carotid artery stenosis include age, smoking, high blood pressure, diabetes, obesity and an inactive lifestyle.
Some people with carotid artery stenosis may experience dizziness, fainting and blurred vision which may be signs of the brain not receiving enough blood. In many cases, the first symptom is a transient ischemic attack (TIA) or a stroke because a small blood clot can form in the area of the vessel that is affected by atherosclerosis. When such a small clot becomes dislodged, it can travel into the brain and plug up a smaller artery on which a particular piece of the brain depends for its function and ultimately survival. Symptoms of a TIA and stroke are similar: paralysis or numbness on one side of the body, blurred vision, headache, trouble speaking and difficulty responding to others. A TIA is usually brief and leaves no lasting damage; it is a due to a very small, temporary occlusion of a small artery but often a warning sign. A stroke is often associated with death of a part of the brain due to loss of its blood supply and can result in severe disability or death.