Carotid Artery Disease
What is carotid artery disease?
The carotid arteries are the main blood vessels that carry blood and oxygen to the brain. When these arteries become narrowed, it’s called carotid artery disease. It may also be called carotid artery stenosis. The narrowing is caused by atherosclerosis. This is the buildup of fatty substances, calcium, and other waste products inside the artery lining. Carotid artery disease is similar to coronary artery disease, in which buildup occurs in the arteries of the heart and can cause a heart attack.
Carotid artery disease reduces the flow of oxygen to the brain. The brain needs a constant supply of oxygen to work. Even a brief pause in blood supply can cause problems. Brain cells start to die after just a few minutes without blood or oxygen. If the narrowing of the carotid arteries becomes severe enough that blood flow is blocked, it can cause a stroke. If a piece of plaque breaks off it can also block blood flow to the brain. This too can cause a stroke.
What causes carotid artery disease?
Atherosclerosis causes most carotid artery disease. In this condition, fatty deposits build up along the inner layer of the arteries forming plaque. The thickening narrows the arteries and decreases blood flow or completely blocks the flow of blood to the brain.
Who is at risk for carotid artery disease?
Risk factors associated with atherosclerosis include:
- Older age
- Family history
- Genetic factors
- High cholesterol
- High blood pressure
- Diet high in saturated fat
- Lack of exercise
Although these factors increase a person’s risk, they do not always cause the disease. Knowing your risk factors can help you make lifestyle changes and work with your doctor to reduce chances you will get the disease.
What are the symptoms of carotid artery disease?
Carotid artery disease may have no symptoms. Sometimes, the first sign of the disease is a transient ischemic attack (TIA) or stroke.
A transient ischemic attack (TIA) is a sudden, temporary loss of blood flow to an area of the brain. It usually lasts a few minutes to an hour. Symptoms go away entirely within 24 hours, with complete recovery. When symptoms persist, it is a stroke. Symptoms of a TIA or stroke may include:
- Sudden weakness or clumsiness of an arm or leg on one side of the body
- Sudden paralysis of an arm or leg on one side of the body
- Loss of coordination or movement
- Confusion, decreased ability to concentrate, dizziness, fainting, or headache
- Numbness or loss of feeling in the face or in an arm or leg
- Temporary loss of vision or blurred vision
- Inability to speak clearly or slurred speech
If you or a loved one has any of these symptoms, call for medical help right away. A TIA may be a warning sign that a stroke is about to occur. TIAs do not precede all strokes, however.
The symptoms of a TIA and stroke are the same. A stroke is loss of blood flow (ischemia) to the brain that continues long enough to cause permanent brain damage. Brain cells begin to die after just a few minutes without oxygen.
The disability that occurs from stroke depends on the size and location of the brain that suffered loss of blood flow. This may include problems with:
- Bowel and bladder function
- Emotional control
- Other vital body functions
Recovery also depends on the size and location of the stroke. A stroke may result in long-term problems, such as weakness in an arm or leg. It may cause paralysis, loss of speech, or even death.
The symptoms of carotid artery disease may look like other medical conditions or problems. Always see your doctor for a diagnosis.
How is carotid artery disease diagnosed?
Along with a complete medical history and physical exam, tests for carotid artery disease may include:
- Listening to the carotid arteries. For this test, your doctor places a stethoscope over the carotid artery to listen for a sound called a bruit (pronounced brew-ee). This sound is made when blood passes through a narrowed artery. A bruit can be a sign of atherosclerosis. But, an artery may be diseased without producing this sound.
- Carotid artery duplex scan. This test is done to assess the blood flow of the carotid arteries. A probe called a transducer sends out ultrasonic sound waves. When the transducer (like a microphone) is placed on the carotid arteries at certain locations and angles, the ultrasonic sound waves move through the skin and other body tissues to the blood vessels, where the waves echo off of the blood cells. The transducer sends the waves to an amplifier, so the doctor can hear the sound waves. Absence of or faintness of these sounds may mean blood flow is blocked.
- MRI scan. This procedure uses a combination of large magnets, radiofrequency energy, and a computer to make detailed images of organs and structures in the body. For this test, you lie inside a big tube while magnets pass around your body. It’s very loud.
- Magnetic resonance angiography (MRA). This procedure uses magnetic resonance technology (MRI) and intravenous (IV) contrast dye to make the blood vessels visible. Contrast dye causes blood vessels to appear solid on the MRI image so the doctor can see them.
- Computed tomography angiography (CTA). This test uses X-rays and computer technology along with contrast dye to make horizontal, or axial, images (often called slices) of the body. A CTA shows pictures of blood vessels and tissues and is helpful in identifying narrowed blood vessels.
- Angiography. This test is used to assess the how blocked the carotid arteries are by taking X-ray images while a contrast dye is injected. The contrast dye helps the doctor see the shape and flow of blood through the arteries as X-ray images are made.