Eric Dane opened up about his recent ALS diagnosis on "Good Morning America," telling Diane Sawyer that he now only has "one functioning arm."

Eric Dane reflects on his ALS diagnosis and the close relationship with Rebecca Gayheart after their reconciliation earlier this year

An emotional Eric Dane, popularly known for starring in the hit American drama series "Grey's Anatomy," opened up about his ALS diagnosis and how it has already left one of his arms