Actor Eric Dane has opened up about his battle with amyotrophic lateral sclerosis (ALS) and is revealing the one symptom — the very first one — he experienced, but didn’t think much of at the time it happened. The former “Grey’s Anatomy” star, 52, revealed this important fact to Diane Sawyer in a new interview on “Good Morning America” Monday.

He emphasized his perseverance moving forward, saying, “I’m fighting as much as I can,” though he admitted, “There’s so much about it that is out of my control.”