The crucial, controversial carotid artery Part II: Treatment
The carotid arteries carry oxygen-rich blood from the heart to the front half of the brain. But these crucial arteries can become narrowed by the cholesterol-laden plaques of atherosclerosis. Blood clots, or thrombi, can form on the plaques, then break off and travel as emboli to the brain, where they lodge in small arteries, interrupting the vital flow of blood to brain cells. If the interruption is partial or brief, the brain cells recover; the patient experiences a transient ischemic attack (TIA) with no permanent damage. But if the blockage is complete, brain cells die, producing a stroke.
In many cases, a TIA warns of a future stroke, giving doctors time to perform a carotid ultrasound test to see if the artery is mildly (less than 50%), moderately (50% to 69%), or severely (70% to 99%) narrowed. Once the diagnosis of carotid stenosis (narrowing) is established, several treatment options must be considered.
Reporting warning symptoms
Patients hold the key to preventing strokes caused by carotid artery stenosis; their task is to recognize warning symptoms (see "The first decision," below) and to report them promptly to their doctors. How well do patients perform as reporters? To find out, investigators surveyed 1,662 patients enrolled in the Asymptomatic Carotid Atherosclerosis Study. At the start of the study, each patient received extensive instruction about warning symptoms and the need for speedy reporting. Despite these educational efforts, fewer than 40% of patients who experienced symptoms reported them within three days, and fewer than 25% reported them within 24 hours. It's a dangerous delay that can have shocking consequences.