As expected, some 75 former professional football players have filed a class-action lawsuit against the NFL, claiming that the league intentionally concealed evidence that repeated concussions could lead to permanent brain damage. In fact, the lawsuit maintains, a study commissioned by the NFL in 1994 and another report published in 2004 concluded that multiple concussions do not have a cumulative effect on the brain. Not Until June of last year, the suit alleges, did the NFL acknowledge that concussions can eventually lead to dementia, memory loss and a condition called CTE (chronic traumatic encephalopathy), a degenerative disease of the brain that often manifests itself years after the original injuries. The brains of several former NFL players, many of whom died at a relatively young age or committed suicide, have been examined by researchers who confirmed the condition. The matter has become an issue during current negotiations between players and owners, with the players arguing that the owners' plans to extend the season from 16 games to 18 increases their risks of serious brain trauma. In the long-gestating lawsuit, whose filing was first reported by TMZ.com, the players claim, "The NFL knew as early as the 1920's of the harmful effects on a player's brain of concussions; however, until June of 2010 they concealed these facts from coaches, trainers, players and the public."