Carotid Artery Stenosis and Stroke
What is it?
The carotid arteries are the two large blood vessels at each side of the neck. Stenosis is a narrowing or blockage of a passageway. So, carotid artery stenosis occurs when the carotid arteries become narrow or blocked by carotid artery disease. Carotid artery stenosis is one of the causes of stroke. A stroke occurs when the lack of blood flow and oxygen to the brain results in a sudden loss of brain function.
Who gets it?
The risk of developing carotid artery stenosis increases with high blood pressure, high blood cholesterol levels, high stress levels, diabetes mellitus, diabetes, cigarette smoking, obesity, lack of exercise, and advanced age.
What causes it?
The carotid arteries are the main supply of blood to the brain. The most common cause of blockage in these arteries is atherosclerosis, in which fatty materials collect under the inner lining of the arterial wall.
As the amount of fatty material increases, it forms a thickened area, called plaque, in the artery’s inner lining. This plaque can rupture and cause blood clots, which can break away and travel to the brain, also causing a stroke. Atherosclerosis is also known as hardening of the arteries.
What are the symptoms?
Most people with carotid artery stenosis usually have no symptoms. Some patients may notice a "swishing" noise in either ear with each heartbeat. This sound may occur as blood flows past a blockage in a carotid artery. If symptoms such as partial paralysis, blindness, or feelings of numbness are present, there is great risk of a major stroke. Symptoms of stroke include paralysis of an arm or leg, vision and speech problems, and personality changes. These symptoms can be permanent. Carotid artery stenosis can also cause transient ischemic attacks
(TIAs), also called “mini strokes.” With a
TIA, small pieces of the fatty materials in the arteries break away and lodge in the small blood vessels leading to the vein. This blocks the blood supply to the brain temporarily and results in symptoms such as blindness in one eye, numbness and tingling of the skin, and weakness of an arm or a leg. TIAs usually last anywhere from 2 to 30 minutes. These symptoms are temporary and reversible, but people who have TIAs are more likely to have a stroke.
How is it diagnosed?
Carotid artery disease is usually detected during a routine physical examination. Your doctor will be able to hear the blood rushing past the blockage in the carotid artery by listening with a stethoscope. An ultrasound test is used to create pictures of the blockage and to measure the amount of blood flowing through the artery. Another frequently used diagnostic test is called a cerebral arteriogram. A special dye is injected into an artery. An x-ray then shows the location and size of the blockage, which are revealed by the path the dye is able to take. If your doctor suspects a stroke, he or she may also order a computed tomography (CT) scan of your head to check brain function. It is important to tell your doctor if you have had any recent episodes of loss of vision or minor paralysis.
What is the treatment?
The treatment for carotid artery stenosis depends upon the degree of blockage and the presence of symptoms. If the carotid artery is less than 70% blocked and you have no symptoms, doctors usually recommend aspirin treatment. One aspirin per day will reduce the likelihood of a blood clot and decrease your chance of stroke. Your treatment will include regular checkups with your doctor to see if your condition changes. If the carotid artery is less than 70% blocked, but you have symptoms, the treatment depends upon the results of the cerebral arteriogram. If this test shows no other problems, patients are usually started on daily aspirin treatment. Again, treatment will include regular checkups for any changes in your condition. However, if the plaque looks rough and irregular, your doctor may recommend surgery to remove the plaque. If the carotid artery is more than a 70% blocked and you have symptoms, the usual treatment is surgery. This procedure, called carotid endarterectomy, involves removing the plaque from the carotid artery. You are placed under general anesthesia and the surgeon makes a small cut (incision) in your neck to expose the artery. He or she then makes a cut in the artery and removes the blockage. The artery is repaired and the incision in your neck is closed with stitches. Following the surgery, you may need to take medicine that makes your blood less likely to clot. There is a one to two percent risk of stroke with this procedure. Another promising procedure is called carotid angioplasty. With this procedure, the area around the carotid artery is numbed with a local anesthetic. Then, a long, thin tube, called a catheter, is passed into the carotid artery in the area of the blockage. The catheter has a balloon on its tip. When the balloon is inflated, it stretches and opens the blocked artery.
Self-care tips
You can help prevent carotid artery stenosis and stroke by following recommendations for preventing atherosclerosis. This means following a diet that is low in fat and cholesterol, exercising regularly, maintaining a healthy weight, and avoiding cigarette smoking.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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