A transient ischemic attack (TIA) is a temporary impairment of brain function that is due to an insufficient supply of blood to part of the brain. The person may be unable to speak or may have slurred speech. He may be weak or paralyzed, dizzy, or nauseated. These symptoms last only a few minutes or hours and totally resolve. This is in contrast to a stroke, in which symptoms are the same but in which the deficits persist for more than twelve hours. Very small deficits may not be noticeable.
