Atherosclerosis of the carotid arteries

What carotid atherosclerosis is

The carotid arteries are the two main arteries, on either side of the neck, that carry blood to the brain. Atherosclerosis is the buildup of plaques (cholesterol, inflammatory cells, calcium) in their walls. The same process that affects the coronary arteries of the heart (see dyslipidemia) can narrow the carotids or make their lining rough.

Stroke from the carotids happens in two main ways: a plaque may narrow the artery so much that blood flow to the brain falls, or, more often, a fragment (embolus) breaks off the plaque surface, or a clot forms and travels to the brain and blocks a small branch. The result is a stroke or a transient ischemic attack (TIA), a brief episode with stroke symptoms that resolves within minutes or hours but is the most important warning of a future stroke.

Most strokes do not come from the carotids (some are linked to atrial fibrillation, others to small vessels of the brain), but carotid disease is an important and preventable cause.

Risk factors

Smoking, hypertension, high cholesterol (LDL), diabetes, age and family history, as well as overweight and inactivity. Most people with carotid plaques have no symptoms. Finding a plaque does not mean you will certainly have a stroke: it is a signal that your cardiovascular risk should be assessed and treated, because people with carotid plaques are more likely to have plaques in other arteries too, including the coronaries.

Signs you should not wait on: remember “FAST”

• Face: one side droops when you smile;
• Arms: one arm weakens or goes numb when you raise it;
• Speech: confused, slurred or words cannot be found;
• Time: call 127 immediately.

Sudden loss of vision in one eye (“a curtain coming down”), a typical carotid sign, is also an emergency. Symptoms that pass by themselves (TIA) must not be ignored: go to the emergency department all the same, because the risk of a full stroke is highest in the first days.

Diagnosis

The first test is a carotid Doppler ultrasound, which is painless and uses no radiation. It shows the plaques, their structure and estimates the degree of narrowing from the speed of blood flow. When more detail is needed, especially before a procedure, CT angiography or MR angiography is requested. After a stroke or TIA the brain is assessed with CT or MRI.

Dizziness alone, without other neurological signs, is usually not caused by carotid disease. Routine carotid screening in all adults without symptoms is not recommended by international guidelines, because most cases found do not change treatment and testing may bring unnecessary risk. The test has value when there are symptoms (TIA, stroke, a bruit in the neck) or a specific indication, according to the doctor’s assessment.

Treatment

Medical treatment is the foundation for everyone:

• stopping smoking, which lowers risk right away;
• blood pressure control (see hypertension);
• lowering LDL cholesterol, usually with statins, to a low target (see dyslipidemia);
• diabetes control, physical activity, healthy eating, weight control;
• antiplatelet drugs (for example aspirin), when your doctor recommends them. Do not start aspirin on your own because of a minor ultrasound finding, since it can cause bleeding without a clear benefit.

Procedures. Surgical removal of the plaque (endarterectomy) or placement of a stent is mainly recommended for significant narrowings that have caused symptoms; for severe narrowings (usually above 70%) with recent symptoms, the procedure is done as soon as possible, usually within two weeks of the symptoms. For narrowings without symptoms, a procedure is considered only in selected high-risk cases and after discussing benefit and risk. The benefit depends on the degree of narrowing, the time since symptoms, age and the risk of the procedure. Not every plaque needs a procedure; for most people, medical treatment is enough.

Follow-up

The schedule of checks is set individually, according to the degree of narrowing and risk. Treatment lowers the risk of stroke and heart attack but does not guarantee that the plaque will disappear; the aim is to keep it stable. Knowing the emergency signs remains important for life, as does taking medicines and keeping check-ups.

This information is educational and does not replace a medical visit.