Carotid stenosis is a narrowing or blockage of the carotid arteries. Located in the side of the neck, the left and right carotids are two large arteries that carry oxygen-rich blood to your brain. You can feel your carotids pulsate when you place your index finger right below the angle of your jaw. Carotid stenosis is dangerous because it can decrease blood flow to the brain. If blood flow to the brain is interrupted, a stroke occurs. According to a 2006 article published in the journal Circulation, 750,000 Americans have strokes every year. (Sobieszczyk and Beckman, 2006)
What Causes Carotid Stenosis?
A buildup of deposits of cholesterol, fat, calcium, and other substances (collectively referred to as plaque) along the lining of the carotid artery is the most common cause of carotid stenosis. This buildup or hardening of the arteries is called atherosclerosis. As plaque deposits in the carotids increase in size, the opening of the carotid artery becomes narrower, and your risk for stroke increases. Plaque makes the inside surface of the carotids rough, and this roughness attracts clot-forming platelets. Sometimes small pieces of clot or plaque can break off, travel through your bloodstream, and cause a blockage in smaller arteries of your brain. Plaque can also rupture and cause clots to form.
Who Is at Risk for Carotid Stenosis?
The same problems that cause plaque to form in the arteries of your heart and leg arteries also cause plaque deposits in the carotid arteries. Some of the factors that increase the risk of carotid stenosis are:
Smoking damages the lining of blood vessels. This increases the risk of cholesterol being deposited inside your arteries.
High Cholesterol Levels
High cholesterol levels increase the chances of plaque formation.
High Blood Pressure
High blood pressure can result in the formation of plaque in the carotids. The systolic blood pressure, which is the uppermost number in your blood pressure reading, should be less than 140. For diabetics, the systolic blood pressure should be less than 130.
Diabetes damages arteries and carries a risk of stroke that is four times greater for diabetics than for nondiabetics. Diabetics are also more likely to have high blood pressure and high cholesterol. (Sobieszczyk and Beckman, 2006)
What Are the Symptoms of Carotid Stenosis?
Carotid stenosis might have no symptoms until a stroke occurs. Symptoms of a stroke include:
- transient blindness in an eye
- permanent blindness
- slurred speech
- weakness in a part of the face, an arm, or a leg
- numbness and tingling in the face, arm, or leg
- memory loss
- inability to speak
- inability to speak coherently
- inability to understand speech
- loss of consciousness
Seek immediate medical attention if you experience any of these symptoms.
How Is Carotid Stenosis Diagnosed?
Diagnosis of carotid stenosis begins by looking at the patient’s medical history and doing a physical examination. When using a stethoscope to listen to the blood flow in your neck, a doctor will be checking for a swooshing sound called a bruit. In addition, the following tests can be useful to confirm a diagnosis of carotid stenosis.
This noninvasive test uses an ultrasound to detect the presence of plaque. A Doppler ultrasound can also tell doctors if the blockage is severe.
Computed Tomography Angiogram (CTA)
This test uses a computed tomography (CT) scan to detect carotid stenosis. A dye is injected into a vein in your arm, and the CT scan takes pictures of the carotids. The dye makes the area of stenosis visible and allows doctors to tell how severe the stenosis is.
Magnetic Resonance Angiogram (MRA)
The test is much like the CTA, but it uses magnetic resonance imaging (MRI) instead of a CT scan.
How Is Carotid Stenosis Treated?
Treatment for the underlying cause for carotid stenosis is essential. People with carotid stenosis who smoke should stop immediately. It takes about five years for your risk of stroke to decrease to the level of a nonsmoker. (Sobieszczyk and Beckman) High blood pressure, diabetes, and high cholesterol have to be treated with diet, exercise, and medication. Controlling these conditions and making lifestyle changes are also the best ways to lower your risk of developing carotid stenosis.
Mild carotid stenosis without severe symptoms can be treated with aspirin. Antiplatelet medications such as aspirin and clopidogrel (Plavix) decrease the ability of platelets to form clots. Sometimes blood thinners such as coumadin are used to reduce stroke risk.
Severe blockage can be treated surgically by removing the plaque. A vascular surgeon who specializes in operating on blood vessels will perform this kind of surgery. The procedure is called carotid endarterectomy.