Carotid Stenosis: A Potential Killer

A friend of my parents’, Linda, came to me with a problem. Lately, she has been dizzy with partial loss of vision in her right eye. When her doctor examined her, he heard an abnormal sound in her neck (called a “bruit”). His concern was she had carotid artery stenosis and was at risk to have a stroke. Her doctor recommended a carotid ultrasound. Upon hearing this, Linda was very worried and wanted to know more.

Q: What is the carotid artery? What is stenosis?
A: We have two carotid arteries located on each side of our neck. It is the pulse we feel when we lightly press on the side or our neck. The carotid arteries carry blood from the heart to the brain. Over time, a waxy substance called plaque can build up in the carotid arteries. Plaque is made up of fat, cholesterol, and blood cells. This plaque can harden and start to calcify. Plaque building up can narrow the inside of the vessel decreasing the amount of blood going to the brain. This is called stenosis and can lead to a stroke. Another fear is that a piece of plaque will become loose and travel with the blood to the brain. This can also lead to a stroke.

Q: What causes this plaque build up?
A: The mechanism of plaque build up is complex. However factors that accelerate plaque build up and stenosis include high blood pressure, high cholesterol and fat in the blood, smoking, and diabetes.

Q: What are the symptoms of carotid stenosis?
A: Sometimes there are no symptoms and the condition is instead detected during a physical exam, as in the case with Linda. Sometimes carotid stenosis can cause a person to have dizziness or vertigo. Sudden partial loss of vision can be from plaque dislodging from the carotid artery wall and traveling to occlude the blood supply of the eye. In severe cases, a patient can present with small, temporary strokes called transient ischemic attacks (TIA). The danger of TIAs is that they often lead to much larger, potentially debilitating strokes.

Q: What is a carotid ultrasound?
A: An ultrasound is a machine that uses sound waves to see inside the body. A probe is placed on the body. Sound waves are transmitted and received by the probe and a computer creates pictures of the body. This works much like sonar on a submarine. Ultrasound is extremely safe, and uses no radiation. The test is inexpensive and it can detect blood flow in real time. The ultrasound can detect plaque and the degree of narrowing inside the blood vessel. It can also detect direction and speed of the blood flow. Treatment can be implemented to decrease the amount of plaque and restore blood flow.

Q: How is this test performed?
A: All jewelry around the neck is removed. It is recom- mended for our patients to wear open neck shirts. The patient lies on a table, facing upwards. The ultrasound technologist places the probe on both carotid arteries and takes pictures. A radiologist interprets these images.

Q: Are there any other tests that can detect stenosis?
A: Sometimes the blood vessels are very tortuous which limits detailed evaluation. Also, the ultrasound cannot see the blood vessels when it enters the skull on its way to the brain. In such cases, a CT scan or MRI can be performed to image the carotid arteries.

Q: If I have stenosis, what can I do?
A: If the amount of plaque is mild and not causing significant stenosis, medications can be used to reduce the amount of cholesterol and fat in the blood as well as to control blood sugar. Exercise is highly encouraged. Smoking cessation is a must! If the stenosis is critical, a vascular surgeon maybe needed to clear the blocked arteries.