Kate Walsh says Eric Dane's health battle is "so painful".
The Grey's Anatomy star - whose character Dr. Addison Montgomery was in a relationship with Eric's alter ego Mark Sloan - has opened up on her castmate's public struggle with Amyotrophic lateral sclerosis (ALS), which is a progressive neurodegenerative disease that affects nerve cells in the brain and spinal cord, leading to muscle weakness and atrophy.
