Causes

Carotid artery disease occurs when sticky, fatty substances called plaque build up in the inner lining of the arteries. See also: Atherosclerosis (hardening of the arteries)

The plaque may slowly block or narrow the carotid artery or cause a clot (thrombus) to form more suddenly. Clots can lead to stroke.

Risk factors for blockage or narrowing of the arteries include:

• Alcohol abuse
• Cocaine use
• Diabetes
• Family history of stroke
• High blood pressure
• High cholesterol
• Increasing age
• Smoking (people who smoke one pack a day double their risk of a stroke)

Two uncommon conditions called Marfan syndrome and fibromuscular dysplasia (abnormal growth or development of the cells in the walls of carotid arteries) may also cause narrowing of the carotid arteries.

Symptoms

You may not have any symptoms of carotid artery disease.

You may have symptoms of a stroke or a transient ischemic attack (TIA). Some of these symptoms include:

• Blurred vision
• Confusion
• Loss of memory
• Loss of sensation
• Problems with speech and language
• Vision loss
• Weakness in one part of your body

Exams and Tests

Your health care provider will perform a physical exam. The health care provider may hear an abnormal sound called a bruit when using a stethoscope to listen to the blood flow in your neck.

A physical exam may also reveal clots in the blood vessels of the eye. If you have had a stroke or TIA, a nervous system (neurological) exam will reveal other problems.

The following tests may be done:

• Blood cholesterol and triglycerides test
• Blood sugar (glucose) test
• Ultrasound of the carotid arteries (carotid duplex Doppler study) to see how well blood is flowing through the carotid artery

The following imaging tests may be used to examine the blood vessels in the neck and brain:

• Carotid or cerebral angiography
• Computerized tomographic angiography (CTA)
• Magnetic resonance angiography (MRA)

Treatment

Treatment options include:

• Blood-thinning medicines such as aspirin, clopidogrel (Plavix), and warfarin (Coumadin) to lower your risk of stroke
• Medicine and diet to lower your cholesterol
• Medicine and diet to control your blood pressure
• No treatment, other than checking your carotid artery with tests every year

There are two invasive ways to treat a carotid artery that is narrowed or blocked. These procedures are done to prevent new strokes in people with large blockages.

• Surgery, called carotid endarterectomy, is done to remove the buildup in your carotid arteries. See: Carotid artery surgery
• Carotid angioplasty and stenting (CAS) is done through a much smaller surgical cut, by pushing instruments into your arteries and placing a wire mesh inside the artery through a tube in the groin.

Outlook (Prognosis)

Stroke is a leading cause of death in the United States. Some people who have a stroke recover most or all of their functions. Others die from the stroke itself or from complications. About half of those who have a stroke have long-term problems.

Possible Complications

The major complications with carotid artery disease are:

• Transient ischemic attack (TIA). This is an episode in which a person has stroke-like symptoms for less than 24 hours, usually less than 1-2 hours. A TIA is often considered a warning sign that a stroke may happen in the future if something is not done to prevent it.
• Stroke. A stroke can happen when a blood vessel in any part of the brain is blocked. The blood flow through the narrowed carotid artery may slow so much that a clot forms. A stroke may also occur if a small piece of a blood clot breaks off and travels to a smaller artery in the brain.

When to Contact a Medical Professional

Go to the emergency room or call the local emergency number (such as 911) as soon as symptoms occur. When having a stroke, every second of delay can result in more brain injury.

Prevention

The following can help prevent a stroke:

• Adults should have their cholesterol checked every 5 years and treated, if needed. If you have been treated for high cholesterol, you will need to have it checked more often.
• Avoid fatty foods. Follow a healthy, low-fat diet.
• Do not drink more than 1 to 2 alcoholic drinks a day.
• Exercise regularly: 30 minutes a day if you are not overweight; 60 - 90 minutes a day if you are overweight.
• Get your blood pressure checked every 1 - 2 years, especially if high blood pressure runs in your family. If you have high blood pressure, heart disease, diabetes, or you have had a stroke, you need to have it checked more often. Ask your doctor.
• Quit smoking.

Follow your doctor's treatment recommendations if you have high blood pressure, diabetes, high cholesterol, or heart disease.

Alternative Names

Carotid stenosis; Stenosis - carotid

References

Brott TG, Halperin JL, Abbara S, Bacharach JM, Barr JD, Bush RL, et al. American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines: American Stroke Association; American Association of Neuroscience Nurses; American Association of Neurological Surgeons; American College of Radiology; American Society of Neuroradiology; Congress of Neurological Surgeons; Society of Atherosclerosis Imaging and Prevention; Society for Cardiovascular Angiography and Interventions; Society of Interventional Radiology; Society of NeuroInterventional Surgery; Society for Vascular Medicine; Society for Vascular Surgery. 2011 ASA/ACCF/AHA/AANN/AANS/ACR/ASNR/CNS/SAIP/SCAI/SIR/SNIS/SVM/SVS guideline on the management of patients iwth extracranial carotid and vertebral artery disease: executive summary: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines, and the American Stroke Association, American Association of Neuroscience Nurses, American Association of Neurological Surgeons, American College of Radiology, American Society of Neuroradiology, Congress of Neurological Surgeons, Society of Atherosclerosis Imaging and Prevention, Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of NeuroInterventional Surgery,; Society for Vascular Medicine, and Society for Vascular Surgery. Vasc Med. 2011;16:35-77.

Brott TG, Hobson RW 2nd, Howard G, Roubin GS, Clark WM, Brooks W, et al. Stenting verses endarterectomy for treatment of carotid-artery stenosis. N Engl J Med. 2010;363:11-23. Epub 2010 May 26.

Update Date: 4/31/2012

Reviewed by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.