can't get this morbid obesity under control. >> larry: we're going to do a lot more investigation tonight. can i ask you a couple questions about concussions? >> yes, sir. >> larry: west virginia has a prominent football team. now in the nfl. and what is a concussion, what causes it? >> well, concussion is either the head gets hit or maybe the head gets moved back and forth violently, such that the brain moves inside the skull. our brain floats in this bath of fluid, cerebrospinal fluid, and i think that causes a tearing of fibers, rotation of the brain causes tearing of the fibers. so the brain is injured. most of the time it covers. but in some cases we're finding a genetic predisposition, and it can lead to long-term problems in a minority of players. >> larry: could a problem be in the helmet?