Dane -- who shot to fame amid six seasons on the hit ABC drama "Grey's Anatomy," where he played Dr. Mark Sloan, affectionately known as "McSteamy" -- said his symptoms began over one year ago, when he began to experience weakness in his right hand.

Eric Dane detailed the heartbreaking effects that ALS has had on his body just two months after the Grey’s Anatomy alum shared his diagnosis with the world.