The recently released movie Concussion tells the story of Dr. Bennet Omalu, the Nigerian-American doctor who discovered the often-fatal effects of head trauma in American football -- but then faced backlash from the National Football League, which governs the sport at the professional level. On the eve of one of America’s most celebrated sporting events – the Super Bowl – VOA’s Mariama Diallo spoke with Dr. Omalu abut his findings -- and the aftermath.