The stroke, also called brain attack, occurs when there is an alteration of the normal flow of blood in the brain. Interruption of the blood flow occurs when a clot or piece of plate blocks one of vital blood vessels in the brain ( ischemic ) accident, either when a blood vessel in the brain bursts, with which blood is spilled in the tissues surrounding ( attack cerebral hemorrhagic ).The brain needs a constant supply of oxygen and nutrients to work. Even a brief interruption in the blood supply can cause problems. The brain cells begin to die within few minutes when they are not receiving blood or oxygen. The area of tissue where there is dead skin cells is called infarction. Due to modifications both physical and chemical that occur in the brain with cerebral attack, can continue producing damage for several days. This phenomenon is called brain attack on evolution.
