Carotid artery disease affects the blood vessels leading to the head and brain. Like heart muscle, brain cells need a constant supply of oxygen-rich blood. Blood is delivered to the brain by two large carotid arteries in the front of the neck and by two smaller vertebral arteries at the back of the neck. A stroke most often occurs when the carotid arteries become blocked, depriving the brain of oxygen.
Carotid artery disease increases the risk of stroke when fatty plaque deposits severely narrow and decrease blood flow through the carotid arteries, when a blood clot becomes wedged in a carotid artery that is narrowed by plaque, or when plaque dislodges from a carotid artery and blocks a smaller artery in the brain (a cerebral artery).
Who is at Risk for Carotid Artery Disease and Stroke?
Each year, approximately 900,000 people in the United States die from heart disease or stroke. Increased age increases the risk of stroke, and more men than women suffer from stroke. Stroke is the number three killer in the United States, and a leading cause of disability among older Americans.
Patients with carotid artery disease usually have severe coronary artery disease or have a parent who died from coronary artery disease. Therefore, the risk factors for carotid artery disease are similar to those for coronary artery disease. These risk factors include:
- High blood levels of low-density lipoprotein (LDL/bad) cholesterol and triglycerides
- High blood pressure
- Family history of coronary artery disease
- Lack of exercise
Although no symptoms are specific to carotid artery disease, the warning signs for stroke may also indicate carotid artery blockage. Transient ischemic attacks (TIAs) are one of the most important warning signs that preclude stroke. Sometimes called “mini-strokes,” TIAs are temporary episodes of headache, dizziness, tingling, numbness, blurred vision, confusion, or paralysis that can last anywhere from a few minutes to a couple of hours. Patients experiencing these symptoms should seek immediate medical attention.
Other signs or symptoms of a carotid artery blockage include:
- Weakness or paralysis of an arm, leg, or the face on one side of the body
- Numbness or tingling of an arm, leg, or the face on one side of the body
- Difficulty swallowing
- Loss of eyesight or blurry eyesight in one eye
- Dizziness, confusion, fainting, or coma
- Sudden, severe headache with no known cause
In most cases, carotid artery disease is diagnosed during a normal checkup. The doctor may ask about stroke symptoms (muscle weakness or numbness, lightheadedness, or trouble talking or seeing) and can use a stethoscope to listen to the carotid artery for a rushing sound called a bruit (“brew-ee”). Bruit sounds are sometimes heard with a minor blockage, but may not always be present, even when carotid artery disease is severe. Other diagnostic tools include Doppler ultrasound imaging, magnetic resonance angiography, oculoplethysmography, arteriography, and digital subtraction angiography.
In addition to treating atherosclerosis or other underlying disorders, lifestyle changes, medicine, and percutaneous catheter interventions or surgery may be needed to offset the effects of carotid artery disease and lower the risk of stroke.
The National Stroke Association recommends lifestyle changes that include quitting smoking; reducing stress; maintaining a healthy weight controlling high blood pressure, cholesterol, diabetes, and heart disease; treating circulation problems that increase the risk for stroke; discovering heart rhythm problems like atrial fibrillation, which increase the risk of blood clots that can lead to stroke; limiting the amount of alcohol and salt consumed; exercising daily; and seeking immediate medical attention if stroke symptoms occur.
Doctors prescribe different medicines for patients with carotid artery disease, including blood-thinning medicines (anticoagulants) to prevent stroke and tissue plasminogen activator (t-PA), a clot-dissolving medicine.
Percutaneous Catheter Interventions
A percutaneous catheteter intervention that is used to treat carotid artery disease is carotid angioplasty. Performed by a cardiologist, it involves using a balloon catheter to flatten plaque blockages against the artery wall and open the passageway. A stent may also be placed in the artery to hold it open.
Texas Heart Institute www.texasheartinstitute.com/HIC/Topics/Cond/CarotidArteryDisease.cfm
Medline Plus www.nlm.nih.gov/medlineplus/stroke.html
American Heart Association www.americanheart.org/presenter.jhtml?identifier=4497