Grey's Anatomy star Eric Dane holds back tears in first interview since devastating motor neurone disease diagnosis

Eric Dane became visibly emotional while discussing his diagnosis with motor neurone disease (MND) also known as amyotrophic lateral sclerosis (ALS), publicly for the first time.

In a teaser shared for his upcoming interview on Good Morning America, the Grey's Anatomy actor shared both his devastation and optimism with Diane Sawyer.

Watch the video above.

"I wake up every day and I'm immediately reminded that this is happening," he said.

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As Sawyer said to him, "It's not a dream", the actor repeated the phrase back to her, shaking his head.

While completely broken by the news, the Euphoria actor appeared cautiously optimistic.

"I don't think this is the end of my story," he said. "I don't feel like this is the end of me."

In Australia, ALS is more commonly known motor neurone disease (MND) or Lou Gehrig's disease.

According to the Mayo Clinic, it is "a nervous system disease that affects nerve cells in the brain and spinal cord".

The disease is a rare and incurable condition that progressively weakens muscles and affects physical function. The exact cause is not known.

Father-of-two Dane, who soared to fame as Dr. Mark Sloan on Grey's Anatomy, first revealed his diagnosis back in April.

"I have been diagnosed with ALS," he told People.

"I am grateful to have my loving family by my side as we navigate this next chapter."

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Dane was set to return to the set of Euphoria for production of season three just days after sharing his diagnosis, which he said he felt privileged to be able to do.

"I feel fortunate that I am able to continue working and am looking forward to returning to set of Euphoria next week," he said.

"I kindly ask that you give my family and I privacy during this time."

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