'Concussion' and the Serious Impact of Repeated Head Trauma | ABC News

Will Smith plays the controversial Dr. Bennet Omalu who discovered the brain disease CTE. -- SUBSCRIBE to ABC NEWS:    / abcnews   Watch More on http://abcnews.go.com/ LIKE ABC News on FACEBOOK   / abcnews   FOLLOW ABC News on TWITTER:   / abc   GOOD MORNING AMERICA'S HOMEPAGE: https://gma.yahoo.com/