Celine Dion no longer has 'control over her muscles' and 'can't find any medicine that works' following her diagnosis of Stiff Person Syndrome.
The Canadian singer, 55, was forced to cancel her world tour earlier this year due to her health struggles, but she told fans she was working 'really hard to build back her strength'.
She revealed last year that she had been diagnosed with a rare and incurable neurological disorder called Stiff Person Syndrome, which affects one in a million people.
Advert
The condition can cause rigidity of the limbs and torso, as well as severe muscle spasms.
Celine said these symptoms affect every aspect of her daily life - including her career.
She said Stiff Person Syndrome 'sometimes causes difficulties when I walk and not allowing me to use my vocal cords to sing the way I’m used to'.
Her older sister Claudette has now given fans of the My Heart Will Go On singer an update on her health, as the progressive condition continues to cause her body to attack its own nerve cells.
Celine's sibling told Canadian news outlet 7 Jours: "She's working hard, but she doesn't have control over her muscles. What breaks my heart is that she's always been disciplined. She's always worked hard.
"Our mother always told her, 'You're going to do it well, you're going to do it properly'.
"It's true that in both our dreams and hers, the goal is to return to the stage. In what capacity? I don't know."
Despite working with the 'top researchers in the field', Claudette says the mum-of-three has seen little improvement.
She continued: "The vocal cords are muscles, and the heart is also a muscle. This is what comes to get me.
"Because it's 1 out of a million case, the scientists haven't done that much research because it didn't affect that many people."
Those who suffer from Stiff Person Syndrome can turn into 'human statues' and may end up unable to walk or talk.
Claudette added: "Some people have lost hope because it's all illness that isn't well known. If only you knew the number of phone calls the Foundation [family charity Fondation Maman Dion] gets about Celine! "People tell us they love her and they're praying for her. She gets so many messages, presents and blessed crucifixes."
She said Celine still intended to return to the stage and was not yet reliant on a wheelchair in October.
Olivia Burke