disease known as cte. >> the disease is linked to traumatic head injuries found in more than 50 diseased nfl players. dorsett sat down with an in depth interview with espn. >> reporter: in his hall of fame career, tony dorsett experienced moments of glory. also, took blows to the head. the worst one, he says, was this violent hit in a cowboys/eagles game in 1984. >> it reminded me of a mack truck hitting a volkswagen. i believe, he just blowed me up. >> did they call that a concussion? >> no, they called that a knockout. >> dorsett says he doesn't know how many concussions he suffered during his 12 years in the nfl, but he says they were numerous, and he still deals with the consequences. >> my memory is getting worse