Walter Koroshetz, of the National Institutes of Health , explains that the National Football League (NFL) and the Department of Defense have little in common. However, as troops return home from war, many facing significant hurdles as they heal from the wounds of combat, scientists and doctors have discovered the same dementia-like disease found in the brain tissue of several NFL players has shown up in the brains of four U.S. veterans exposed to improvised explosive devices and other head trauma. This suggests that a common thread binds those exposed to traumatic brain injury, whether it occurs on the football field or on the battlefield. Watch as Dr. Koroshetz discusses recent studies that compared the brains of military veterans who suffered from a blast, athletes who had suffered one or more concussions, and mice that were exposed to a blast.