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 is continuing to open up about his ALS battle and diagnosis, with his doctor sharing new insight into the actor's health journey. In a continuation of his sit-down with Diane Sawyer, Dane and Dr.