The San Francisco-born actor and Janell Shirtcliff, his on-again, off-again girlfriend, were spotted on a date night at Chateau Marmont Tuesday after he shared his health struggles on Good Morning

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.

Dane is set to share intimate details about his diagnosis in a new "Good Morning America" interview with Diane Sawyer.