We see them in the emergency room: people who were going about their normal lives just moments earlier and suddenly cannot speak clearly, move an arm or stand on their feet. From the moment they arrive at the hospital, a race against time begins. Every minute that a blood vessel in the brain remains blocked, millions of nerve cells can suffer irreversible damage. For years, the medication used to dissolve these clots has required an intravenous infusion lasting about an hour.
