“CTE is linked to repetitive brain trauma and has a distinct pathology that can only be diagnosed at autopsy,” says Dr. Ross Zafonte, a principal investigator of the Football Players Health Study at Harvard University and executive vice dean at the University of Missouri.

The degenerative brain disease that has besieged the National Football League for two decades with a billion-dollar lawsuit, congressional hearings, an A-list movie and an unrelenting cortege of