Celine Dion has been largely silent about her diagnosis of stiff-person syndrome, an extremely rare neurological illness that hinders her vocal abilities, for the past year since her announcement.

Claudette Dion, Céline Dion's sister, claimed last week that her Grammy-winning sister "doesn't have control of her muscles," as The LA Times reported.

“There are some who have lost hope because it is a disease that is not [very well] known,” she told Canada’s 7 Jours. "What pains me is that she has 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.’”

More from Claudette

The elder Dion revealed that Celine wants to perform again, but she's not sure how that would look given the singer's declining health: “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 Dion said.

“The vocal cords are muscles, and the heart is also a muscle. This is what comes to get me. Because [Dion’s condition is a] one out of a million case, the scientists haven’t done that much research because it didn’t affect that many people.”

This performer made her stiff-person syndrome diagnosis public in December 2022. This neurological condition "affects something like one in a million people," she stated in a video that was broadcast in both English and French.

According to the Mayo Clinic, "progressive, severe muscle stiffness and spasms of the lower extremities and back" are common symptoms of stiff-person syndrome, an autoimmune condition affecting the neurological system.

A number of Dion's jobs have been canceled since she announced her condition. She canceled her round-the-world tour for Courage in May.

Previous Updates

Claudette has previously provided health updates on her sister: “It’s an illness we know so little about. ... There are spasms — they’re impossible to control,” she said in an August interview with Hello! magazine.

“You know people who often jump up in the night because of a cramp in the leg or the calf? It’s a bit like that, but in all muscles. There’s little we can do to support her, to alleviate her pain.”

Claudette pointed out Dion and her family have limited choices due to the disorder's lack of treatment and said "We're crossing our fingers that researchers will find a remedy for this awful illness."

The singer of "My Heart Will Go On" and her son René-Charles Angélil attended the Montreal Canadiens game against the Golden Knights at the T-Mobile Arena in Las Vegas in October.

Dion, who has made few public appearances since receiving her prognosis, also met with hockey veteran and coach Martin St. Louis.

“I remember when you were 14 years old, you sang for the pope. ‘Une colombe [‘A Dove’],’ ” St. Louis said in French of the singer’s 1984 performance at the Olympic Stadium in Greece.

“It’s been a while since then,” she responded. “We’ve changed a little since then, but not too much.”