The two carotid arteries--one on either side of the neck--carry blood from the heart to the brain. As with all arteries, the carotids are subject to the build-up of plaque, a fatty substance that sticks to the artery walls. If enough plaque builds up, the artery becomes narrowed and stiff, and the blood flow slows. This type of atherosclerosis is called carotid artery disease or carotid artery stenosis. At its most serious, the blood flow is completely blocked, cutting off oxygen to the brain, leading to a stroke.
No Early Warning Symptoms
Carotid artery disease often goes unnoticed until its most serious consequences occur because it has no obvious early warning symptoms. Some people may experience unexplained sudden severe headaches, occasional numbness or tingling in one of their limbs or trouble swallowing, but these are likely to be part of a complex of symptoms that occur when the disease is already well advanced.
Transient Ischemic Attacks and Strokes
When grouped together, the headaches and other signs noted above are more commonly associated with transient ischemic attacks, or TIAs. These are often called "little strokes" because they mimic many of the symptoms of a full-blown stroke--weakness on one side of the body, disturbed vision, slurred or absent speech and confusion. The difference is the transient nature of the symptoms, meaning they clear up almost immediately, even without medical intervention. They are, however, one of the surest signs of a blockage in an artery, and that artery is frequently one of the carotids. Even if they clear up, you need to tell your doctor if you've experienced any of these symptoms.
Unfortunately, a cardiovascular accident (CVA or, by its more common name, a stroke) is a sign--and too often the first sign--of a blocked carotid artery.
Symptoms Found During Physical Examination
Having regular physical exams is probably the best way to turn up signs of carotid artery disease. Besides querying you about symptoms such as headaches; blurred vision; episodes of confusion or numbness; and tingling in your face, arms or legs, your doctor will listen to how the blood is flowing through your carotid arteries. Although none of these present a definitive sign, adding them up will often tell your doctor whether further testing is called for. The most common test is ultrasound imaging, also called Doppler ultrasound imaging, or carotid duplex ultrasonography, which creates a picture of the blood flow through the artery.
Other tests that can determine the degree of blockage in the carotid arteries are computed tomography (CT) scanning and CT angiography (CTA), magnetic resonance angiography (MRA), oculoplethysmography, arteriography and digital subtraction angiography. All of these are more invasive than the ultrasound test. However, ultrasound tests are not without their drawbacks. Although useful for those most prone to carotid artery disease, the U.S. Preventive Services Task Force in 2007 recommended against its routine use in healthy subjects because the benefits do not outweigh the risks.
