Of the 111 brains of deceased National Football League players studied by neuropathologist Dr. Ann McKee, 110 of them had chronic traumatic encephalopathy, a degenerative brain disease believed to be caused by repeated head trauma. A new study published in The Journal of the American Medical Association shows significant scientific evidence that NFL players risk developing C.T.E., which can arise years after an athlete has stopped receiving repeated blows to the head and can only be diagnosed after death. However, Dr. McKee warned that “there’s a tremendous selection bias” in her study, given that many families donated brains because the former player had shown C.T.E. symptoms.
SOURCE: The Daily Beast