The crucial, controversial carotid artery Part I: The artery in health and disease
You don't have to be a brain surgeon to know it is vitally important for your brain to receive an uninterrupted supply of blood. That's because nerve cells require a constant supply of oxygen. Even a brief disruption stuns nerve cells, impairing their function, while more prolonged oxygen deprivation kills the cells. If only a small, noncritical area of your brain is affected, you may not notice the damage. Unfortunately, however, the damage is often very noticeable indeed. Brief or partial interruptions of blood flow cause transient ischemic attacks (TIAs), while prolonged or complete blockages are the major cause of cerebrovascular accidents — strokes.
Stroke is the fourth leading cause of death in the United States, taking about 136,000 lives annually. Another 660,000 Americans survive strokes each year, but many are so disabled that they cannot return to work. In human terms, it's an enormous burden of suffering; in dollar terms, it costs $74 billion a year to care for stroke victims and make up for their lost productivity.