Celine Dion has lost control of her muscles, her sister reportedly told a Canadian website, a year after the pop star announced she was cancelling her tour as she battled stiff person syndrome.

According to Forbes, Claudette Dion, also a singer, told the Canadian website 7 Jours her sister works hard but “does not have control of her muscles.”

While Claudette said her sister aspires to return to the stage, it is unclear what a comeback might look like given the effects of the disease.

“There are some who have lost hope because it is a disease that is not [very well] known,” Claudette 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,’” she added.

This is not the first time Claudette has updated the public on her sister’s health. In an August interview with Hello! Magazine, she described the spasms her sister experiences.

“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.”

In May, Celine announced she was cancelling her 2023-2024 world tour to “build back strength” after her diagnosis with stiff-person syndrome. That announcement came almost five months after she first postponed her 2023 tour dates.

Stiff person syndrome is a rare autoimmune disease that causes people to develop “abnormal, often hunched-over postures” and occasional affects people’s ability to walk, according to the National Institute of Neurological Disorders and Stroke.

Other symptoms include sensitivity to touch, stiff muscles in the arms, legs and torso, and noise and emotional distress that can trigger muscle spasms, according to Columbia University’s Irving Medical Center.

The disease is incurable, according to Yale Medicine.