Cerebrovascular disease is any disorder that occurs in the blood vessels that feed oxygen-rich blood to the face and brain. Most often, this term is used to describe “hardening” (atherosclerosis) of the carotid arteries.

The two carotid arteries are located on the front part of the neck (one on the left and one on the right) and supply the front two-thirds of the brain with blood. About halfway up the neck, each carotid artery splits into two branches, one going straight to the brain (the internal carotid artery) and the other supplying the face (the external carotid artery).

The artery widens at this branch point, which is referred to as the “carotid bulb,” then narrows into the smaller arteries. Because of this structure, lesions in the carotid arteries tend to affect this branch point and the first few centimeters of the internal carotid arteries.

This form of cerebrovascular disease is referred to as carotid artery disease. It is by far the most common form of cerebrovascular disease, accounting for more than 95 percent of cases. The condition can be classified as a type of ischemic disease, or a disease that causes a lack of blood flow, and as a type of peripheral artery disease.

Carotid cerebrovascular disease is particularly dangerous because it often has no symptoms. The major concern with this condition is that pieces of the plaque may break off (rupture) and travel to the brain (becoming an embolism). This condition may cause a stroke or transient ischemic attack (TIA). Treatment of carotid artery disease is designed to prevent stroke and the subsequent damage from the event.

In contrast to ischemic disease, which involves a lack of blood flow to the brain, hemorrhagic cerebrovascular disease is characterized by bleeding into the brain. This bleeding can be slow and gradual, often caused by trauma or high blood pressure. It also may be acute, caused by a rupture in the artery wall (aneurysm). Treatment of hemorrhagic cerebrovascular disease is aimed at stopping the bleeding and preventing the reoccurrence.

According to the Centers for Disease Control (CDC), there were over 162,000 cerebrovascular-related deaths in the United States in 2003. The majority of these deaths occurred in people age 65 and older. The most recent statistics from the American Heart Association (AHA) estimate that over 5 million people have experienced a stroke.