ALS disease explained as Grey’s Anatomy star Eric Dane reveals first symptom he experienced before shock diagnosis

Grey’s Anatomy star Eric Dane has recently opened up about the very first symptom he experienced before receiving his diagnosis of amyotrophic lateral sclerosis (ALS).

Dane, who starred on the hit ABC medical drama as Dr Mark Sloan, spoke about his health journey, after first being diagnosed with ALS back in April, on Good Morning America earlier this week where he told Diane Sawyer that he now only has 'one functioning arm'.

"My left side is functioning, my right side has completely stopped working," the Euphoria star explained, noting that his left arm has been getting weaker as well.

"I feel like maybe a couple more months and I won’t have my left hand either. It’s sobering."

Dane walked his first red carpet since his diagnosis on Wednesday (18 June) for the premiere of his show Countdown, revealing that he is currently prepping for the third season of Euphoria and is determined to keep acting despite his health issues.

He told Variety: "It always feels great to be on a set. It’s great to be employed. I love what I give. I’m going to keep doing it."

What is ALS?

ALS - or amyotrophic lateral sclerosis - is a type of motor neurone disease which sees muscle weakness in the arms and legs that can cause you to trip and drop things.

It is also often called Lou Gehrig's disease after the baseball player who was diagnosed with it.

What are the symptoms of ALS?

While symptoms of ALS differ from person to person, as they depend on which nerve cells are affected, ALS usually starts with muscle weakness that spreads and worsens as time goes on.

According to the Mayo Clinic, other symptoms might include:

• Trouble walking or doing usual daily activities.
• Tripping and falling.
• Weakness in the legs, feet or ankles.
• Hand weakness or clumsiness.
• Slurred speech or trouble swallowing.
• Weakness associated with muscle cramps and twitching in the arms, shoulders and tongue.
• Untimely crying, laughing or yawning.
• Thinking or behavioural changes.

What was Eric Dane's first symptom of ALS?

While he was first diagnosed with ALS a few months back, Dane first started having symptoms a year and a half ago when he began to experience weakness in his right hand.

Speaking to Sawyer during the interview, Dane recalled: "I didn’t really think anything of it at the time.

"I thought maybe I’d been texting too much or my hand was fatigued, but a few weeks later I noticed it got a little worse.

"So I went and saw a hand specialist, who sent me to another hand specialist. I went and saw a neurologist and the neurologist sent me to another neurologist and said, 'This is way above my pay grade'."

"I will never forget those three letters," Dane said. "It’s on me the second I wake up. It’s not a dream."

The actor began to tear up when praising his wife, Rebecca Gayheart, with whom he shares two daughters.

"We have managed to become better friends and better parents," he gushed. "She is probably my biggest champion and my most stalwart supporter, and I lean on her."

'I was heart broken'

While he still has the ability to walk, Dane also opened up about the concern surrounding the functionality in his legs, sharing a particularly alarming experience snorkelling with his daughter where he realised he didn’t have enough energy to swim, prompting his daughter to rescue him out the water.

"She dragged me back to the boat," Dane said. "I was like, breaking down in tears. I made sure she got back to the water with her friend and continued on with the snorkelling. I was just heart broken."

Dane added that he is 'very' angry about the diagnosis due to losing his own father when he was just seven years old to suicide.

"I’m angry because my father was taken from me when I was young, and now there’s a very good chance I’m going to be taken from my girls when they’re very young," he added.

What is the cause of ALS?

The Mayo Clinic explains that, for about 10 percent of people with ALS, a genetic cause can be identified.

However, for the rest, the cause is not known.

The Centers for Disease Control and Prevention (CDC) states that although no one knows for sure, reports suggest that less than 30,000 people in the United States have ALS.

Is there a cure for ALS?

There is currently no cure for ALS, and people diagnosed with the condition usually live three to five years after diagnosis, according to the Muscular Dystrophy Association.

However, with that said, some patients can live for decades.

You can find out more about motor neurone disease (MND) on the official NHS website here.