The head injury Natasha Richardson sustained in a skiing accident produced what doctors call "walk and die" syndrome, a UCLA neurologist tells the Los Angeles Times. Patients in such cases at first seem fine, walking and talking normally, but they swiftly deteriorate due to delayed bleeding from an artery in the brain, which can push the brain left or right and leak into the brainstem.
Such injuries are rare, "but they do occur, even in patients that have been evaluated by a CT scan," a neurosurgeon said. "That's why, when a person has a head injury, we like to observe them for 24 hours to make sure no delayed bleeding occurs." He added that a torn artery in the neck, which results in similar symptoms but tends to be more lethal, could have also felled Richardson.