Will Smith says sports drama "Concussion" is personal for him

Hollywood star Will Smith deals with football-related brain trauma in "Concussion", a sports drama which has already drawn some controversy ahead of its release. The film tells the story of Nigerian-born forensic pathologist Dr Bennet Omalu, who diagnosed Chronic Traumatic Encephalopathy (CTE), a degenerative brain disease, in U.S. football players. In September, the New York Times reported Sony Pictures Entertainment executives had altered the movie's script to avoid antagonizing the National Football League (NFL).