http://healthmad.com

The brain is a glutton. It demands one-fifth of the blood the heart pumps. But it also starves quickly. If its supply of blood is reduced for any reason, permanent damage can occur within five minutes. That’s what happens when a stroke occurs—a sudden interruption in the blood flow to the brain and subsequent brain damage. Four out of five victims will survive the first stroke with only partial brain damage and handicaps of varying degrees.