Overview
The largest artery in your body is the aorta, which leads from the heart to the abdomen. The carotid arteries extend from the aorta to the brain, and supply blood to the brain. If you press gently on either side of your windpipe, in your neck, you may feel pulsations from the carotid arteries.
Like any artery in the body, the carotid arteries may become diseased and blocked inside, either partly or completely. This is a little like the ‘furring up’ of the inside of washing machines or kettles in hard-water areas. The material that is deposited inside the arteries is called atheroma, from the ancient Greek word for porridge and is essentially a fatty deposit. It forms a mound or plaque. This will eventually cause a narrowing in the carotid artery, which is called stenosis.
As more plaque builds up, the arteries narrow and stiffen. This process is called atherosclerosis and is more likely to happen with aging. Only 1% of adults aged 50-59 have significantly narrowed carotid arteries, but 10% of adults aged 80-89 have this problem.
Symptoms
The build-up of atheroma in a carotid artery can cause a number of problems. Parts of the fatty deposit may break off and travel to the brain in the blood stream. When these particles lodge in a smaller artery in the brain they may cause a mini-stroke (called a transient ischaemic attack or TIA) or a full-blown stroke. The severity of the problem caused is difficult to predict and depends on where these particles go.
If these particles travel to the brain, you may experience loss of speech, weakness or numbness of an arm or perhaps an arm and a leg on one side of the body. The side of the body experiences weakness depends on which carotid artery has caused the problem.
The left-half of the brain controls the right side of the body and the right side of the brain controls the left side of the body, as human beings are ‘cross-wired’. Therefore, if the particles break off from plaque in the right carotid artery and travel to the right side of the brain, the patient may experience weakness in the left arm and/or leg.
For most right-handed people, the speech control centre of the brain is situated on the left, so disease in the left carotid artery may lead to speech problems.
Alternatively, visual problems may occur where it seems as if a curtain has come down over one eye. This happens because the particles have travelled to the artery supplying the eye.
You may experience the following symptoms:
- Weakness, numbness, or a tingling sensation on one side of your body, for example, in an arm or a leg
- Inability to control the movement of an arm or a leg
- Losing vision in one eye, as if there were a curtain or a shutter
- Inability to speak clearly
Sometimes the fragments that lodge in the brain or the eye break up and blood flow is restored. In these circumstances, the symptoms are temporary.
If the symptoms clear up within 24 hours then it has been a mini-stroke (TIA).
However, these symptoms should not be ignored and a mini-stroke is a warning that you may be at risk of having more mini-strokes or a full-blown stroke. These symptoms should be reported to your family practitioner immediately, as the highest risk seems to be soon after your first symptoms.
If the symptoms do not improve within 24 hours, you have probably experienced a stroke. It is recommended that you contact your family practitioner, as you may experience further and possibly more disabling strokes without appropriate treatment.
Diagnosis
Your doctor will first ask about your general health and medical history, including about risk factors such as whether you smoke and about the frequency and timing of your symptoms. You will have a physical examination and your blood pressure may be measured. You may also have an electrocardiogram (ECG) and chest X-ray.
Your doctor may also use other imaging techniques to diagnose you, such as Doppler, magnetic resonance angiography, angiography and CT.
Treatment
The first treatment strategy is to address any risk factors you have, such as stopping smoking. Secondly, you will need to be on the combination of medicines that is most suitable for you to prevent further build-up of plaque and to try to stabilise the plaque that has already built up; this is called ‘best medical therapy’. You may be offered medications such as aspirin, statins or ACE inhibitors.
Alternatively, you may be treated using surgery, in an operation called carotid endarterectomy (CEA). Interventional radiology can also treat carotid artery disease, using a procedure called carotid artery stenting. This involves placing a stent (a metal mesh tube) in the vessel to keep it open, preventing plaque from blocking the vessel.