Carotid artery disease is also called carotid artery stenosis. The term refers to the narrowing of the carotid arteries. This narrowing is usually caused by the buildup of fatty substances and cholesterol deposits, called plaque. Carotid artery occlusion refers to complete blockage of the artery. When the carotid arteries are obstructed, you are at an increased risk for a stroke, the 5th leading cause of death in the U.S.
What Are the Carotid Arteries?
The carotid arteries are two large blood vessels that supply oxygenated blood to the large, front part of the brain. This is where thinking, speech, personality, and sensory and motor functions reside. You can feel your pulse in the carotid arteries on each side of your neck, right below the angle of the jaw line.
How Does Carotid Artery Disease Happen?
Like the arteries that supply blood to the heart -- the coronary arteries -- the carotid arteries can also develop atherosclerosis or “hardening of the arteries” on the inside of the vessels.
Over time, the buildup of fatty substances and cholesterol narrows the carotid arteries. This decreases blood flow to the brain and increases the risk of a stroke.
A stroke -- sometimes called a “brain attack” -- is similar to a heart attack. It occurs when blood flow is cut off from part of the brain. If the lack of blood flow lasts for more than three to six hours, the damage is usually permanent. A stroke can occur if:
- The artery becomes extremely narrowed
- There’s a rupture in an artery to the brain that has atherosclerosis
- A piece of plaque breaks off and travels to the smaller arteries of the brain
- A blood clot forms and obstructs a blood vessel
Strokes can occur as a result of other conditions besides carotid artery disease. For example, sudden bleeding in the brain, called intracerebral hemorrhage, can cause a stroke. Other possible causes include:
- Sudden bleeding in the spinal fluid space -- subarachnoid hemorrhage
- Atrial fibrillation
- High blood pressure
- Blockage of tiny arteries inside the brain
What Are the Risk Factors for Carotid Artery Disease?
The risk factors for carotid artery disease are similar to those for other types of heart disease. They include:
- Hypertension (high blood pressure) -- the most important treatable risk factor for stroke
- Abnormal lipids or high cholesterol
- Insulin resistance
- Sedentary lifestyle
- Family history of atherosclerosis, either coronary artery disease or carotid artery disease
Men younger than age 75 have a greater risk than women in the same age group. Women have a greater risk than men older than age 75. People who have coronary artery disease have an increased risk of developing carotid artery disease. Typically, the carotid arteries become diseased a few years later than the coronary arteries.
What Are the Symptoms of Carotid Artery Disease?
You may not have any symptoms of carotid artery disease. Plaque builds up in the carotid arteries over time with no warning signs until you have a transient ischemic attack(TIA) or a stroke.
Signs of a stroke may include:
- Sudden loss of vision, blurred vision, or difficulty in seeing out of one or both eyes
- Weakness, tingling, or numbness on one side of the face, one side of the body, or in one arm or leg
- Sudden difficulty in walking, loss of balance, lack of coordination
- Sudden dizziness and/or confusion
- Difficulty speaking (called aphasia)
- Sudden severe headache
- Problems with memory
- Difficulty swallowing (called dysphagia)
What Is a Transient Ischemic Attack (TIA)?
A TIA occurs when there is low blood flow or a clot briefly blocks an artery that supplies blood to the brain. With a TIA, you may have the same symptoms as you would have for a stroke. But the symptoms only last a few minutes or few hours and then resolve.
A TIA is a medical emergency because it is impossible to predict whether it will progress into a major stroke. If you or someone you know experiences any of the above symptoms, get emergency help. Immediate treatment can save your life and increase your chance of a full recovery.
Findings show that someone who has experienced a TIA is 10 times more likely to suffer a major stroke than a person who has not had a TIA.
How Is Carotid Artery Disease Diagnosed?
There are often no symptoms of carotid artery disease until you have a TIA or stroke. That’s why it’s important to see your doctor regularly for physical exams. Your doctor may listen to the arteries in your neck with a stethoscope. If an abnormal sound, called a bruit, is heard over an artery, it may reflect turbulent blood flow. That could indicate carotid artery disease.
Listening for a bruit in the neck is a simple, safe, and inexpensive way to screen for stenosis (narrowing) of the carotid artery, although it may not detect all blockages. Some experts believe that bruits may be better predictors of atherosclerotic disease rather than risk of stroke. Be sure to let your doctor know if you have had any symptoms, such as those listed above.
Your doctor may also use a test to diagnose carotid artery disease. Possible tests include the following:
- Carotid ultrasound (standard or Doppler). This noninvasive, painless screening test uses high-frequency sound waves to view the carotid arteries. It looks for plaques and blood clots and determines whether the arteries are narrowed or blocked. A Doppler ultrasound shows the movement of blood through the blood vessels. Ultrasound imaging does not use X-rays.
- Magnetic resonance angiography (MRA). This imaging technique uses a powerful magnet to gather accurate information about the brain and arteries. Then a computer uses this information to generate high-resolution images. An MRA can often detect even small strokes in the brain.
- Computerized tomography angiography (CTA). More detailed than an X-ray, a CT uses X-rays and computer technology to produce cross-sectional images of the carotid arteries. Images of the brain can be collected as well. With this imaging test, the scan may reveal areas of damage on the brain. The CT scan uses a low level of radiation.
- Cerebral angiography (carotid angiogram). This procedure is considered the gold standard for imaging the carotid arteries. It is an invasive procedure that lets a doctor see blood flow through the carotid arteries in real time. Cerebral angiography allows the doctor to see narrowing or blockages on a live X-ray screen as contrast dye is injected in the carotid arteries. This procedure provides the best information. It does carry a small risk of serious complications.
What’s the Treatment for Carotid Artery Disease?
To effectively treat carotid artery disease, doctors recommend the following:
- Following recommended lifestyle habits.
- Taking medications as prescribed.
- Considering a procedure to improve blood flow, if your doctor believes it could help reduce your risk of future stroke.
What Are the Recommended Lifestyle Changes for Carotid Artery Disease?
To keep carotid artery disease from progressing, the following lifestyle changes are recommended:
- Quit smoking.
- Control high blood pressure.
- Control diabetes.
- Have regular checkups with your doctor.
- Have your doctor check your cholesterol and get treatment, if necessary.
- Eat a heart-healthy diet.
- Maintain a healthy weight.
- Exercise at least 30 minutes most days of the week.
- Limit alcohol to 1 drink per day for women, 2 for men.
Which Drugs Can Reduce the Risk of Stroke?
Your doctor may recommend antiplatelet medications such as aspirin and clopidogrel (Plavix) to decrease the risk of stroke caused by blood clots. Your doctor may also prescribe medications to lower cholesterol and blood pressure. In some cases, warfarin (Coumadin), a blood thinner, may be prescribed.
What Medical Procedures Treat Carotid Artery Disease?
If there is severe narrowing or blockage in the carotid artery, a procedure can be done to open the artery. This will increase blood flow to the brain to prevent future stroke. Your doctor may suggest either of the following procedures:
- Carotid endarterectomy (CEA). This has been the commonly performed procedure for patients who have carotid atherosclerosis and TIAs or mild strokes. While you’re under general anesthesia, an incision is made in the neck at the location of the blockage. The surgeon isolates the artery and surgically removes the plaque and diseased portions of the artery. Then, the artery is sewn back together to allow improved blood flow to the brain. The risks and benefits of CEA depend on your age, the degree of blockage, and whether you’ve had a stroke or TIA.
- Carotid artery stenting (CAS). Carotid artery stenting (CAS) is a newer treatment option. It’s less invasive than carotid endarterectomy and is performed in a catheterization laboratory. With CAS, a small puncture is made in the groin. A specially designed catheter is threaded to the area of narrowing in the carotid artery. Once in place, a small balloon tip is inflated for a few seconds to open the artery. Then, a stent is placed in the artery and expanded to hold the artery open. A stent is a small tube that acts as a scaffold to provide support inside your artery. The stent is usually made of metal and is permanent. It can also be made of a material that the body absorbs over time. Some stents have medicine that helps keep the artery from getting blocked again. CAS is a newer procedure, and there is still some controversy as to how well it prevents strokes caused by carotid artery disease. Research suggests that the standard CEA may be safer than CAS, which may raise the risk of stroke or death post procedure.