Celine Dion has lost control of her muscles due to stiff-person syndrome, says sister

• Celine Dion's sister says the singer doesn't have control over her muscles at the moment.
• In 2022, Dion announced that she had been diagnosed with stiff-person syndrome.

Celine Dion's sister says the singer has lost control of her muscles as a result of stiff-person syndrome.

The star announced her diagnosis in December 2022 and canceled her 2023 tour, but her condition has since worsened, according to Claudette Dion.

Claudette gave an update about her sister's health in an interview with the French-Canadian magazine 7 Jours published last week.

"She works hard, but she doesn't have control of her muscles," said Claudette.

The condition can cause periodic muscle stiffness and painful spasms. There isn't a cure for stiff-person syndrome, which is a neurological disorder, but it can be managed with a mix of muscle relaxants and sedatives, as Business Insider's Marianne Guenot previously reported.

Claudette, who is also a singer, went on to say that her sister has always been dedicated to her career, which is why her condition is so upsetting.

"What breaks my heart is that she's always been disciplined. She's always worked hard," she said. "Our mother always told her, 'You're going to do this right, you're going to do this right.'"

Claudette also addressed whether Dion will be able to perform on stage again in the future.

"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," Claudette said."The vocal cords are muscles, and the heart is also a muscle."

The star's sister said that there hasn't been enough research into stiff-person syndrome because it is so rare.

"This is what comes to get me. Since it's one case in millions, scientists didn't do that much research, because it didn't affect that many people," said Claudette.

Representatives for Dion did not immediately respond to Business Insider's request for comment.

In September, Dion's sister said that the "My Heart Will Go On" singer has been struggling with full-body spasms, and that there isn't much the family could do to alleviate her pain.

Dion first told fans about her condition in an Instagram post last year, explaining that it has impacted her singing ability.

"Unfortunately, these spasms affect every aspect of my daily life, sometimes causing difficulties when I walk and not allowing me to use my vocal cords to sing the way I'm used to," she said.