Carotid stenosis, or carotid artery disease, is a narrowing or blockage of the carotid arteries. Located in the side of your neck, your 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 your brain. If blood flow to your brain is interrupted, you can have a stroke. About 800,000 Americans have strokes every year.
Carotid stenosis might have no symptoms until a stroke occurs. Symptoms of a stroke include:
- transient blindness in your eye
- permanent blindness
- slurred speech
- weakness in a part of your face, arm, or leg
- numbness and tingling in your face, arm, or leg
- memory loss
- inability to speak
- inability to speak coherently
- inability to understand speech
- loss of consciousness
You should call 911 or go to an emergency room if you experience any of these symptoms, even if the symptoms go away after a short while. It could be a warning sign or a transient ischemic attack (TIA), which means you are at risk for a full-blown stroke.
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 your carotid artery becomes narrower, and your risk for stroke increases. Plaque makes the inside surface of your carotids rough, and this roughness attracts platelets, the blood cells that help your blood clot. Sometimes small pieces of clot or plaque can break off, travel through your bloodstream, and cause a blockage in smaller arteries in your brain. Plaque can also rupture and cause clots to form.
The same problems that cause plaque to form in the arteries of your heart and leg arteries also cause plaque deposits in your 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 your carotids. Your systolic blood pressure, which is the uppermost number in your blood pressure reading, should be less than 140. If you have diabetes, your systolic blood pressure should be less than 130.
Diabetes damages arteries. People with diabetes are two to four times as likely to have a stroke as people without diabetes. People with diabetes are also more likely to have high blood pressure and high cholesterol.
To diagnose carotid stenosis, your doctor may begin by looking at your medical history and doing a physical examination. Your doctor may use a stethoscope to listen to the blood flow in your neck and check for a swooshing sound called a bruit. The following tests can also help your doctor 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 is used to take pictures of your carotids. The dye makes the area of stenosis visible and allows doctors to tell how severe the stenosis is.
Magnetic Resonance Angiogram (MRA)
This test is much like the CTA, but it uses MRI instead of a CT scan.
Treatment and Prevention
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 blood 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.
Treatment for the underlying cause for carotid stenosis is essential. People with carotid stenosis who smoke should quit immediately. 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.