Miami Dolphins cornerback Patrick Surtain leaves the field after a 2003 practice, in which he diidn't participate due to injury. He is one of scores of players suing the NFL over the effects of brain trauma. JOE RIMKUS JR. / Miami Herald Staff

In this Set. 18, 2007 file photo, former Chicago Bears safety Dave Duerson testified on Capitol Hill about legislation that could help cut down on concussions in youth football players. Duerson, a successful businessman after his playing days were over, killed himself in South Florida last year. He had suffered a series of setbacks that he believed were related to brain trauma inflicted on the football field. Susan Walsh / AP

Oronde Gadsden -- a former Miami Dolphins wide receiver, now retired -- is one of scores of players suing the NFL over blows to the head suffered on the field. Donna E. Natale Planas

San Francisco 49ers player Merton Hanks (36) is chased by the Philadelphia Eagles' Kevin Turner (34 ) as he runs for a touchdown after recovering a fumble in 1997. Turner is suing the NFL, saying repeated blows to the head brought on Lou Gehrig's disease after his playing days were over. RUSTY KENNEDY / AP