Dion announced she had been diagnosed with Stiff Person Syndrome (SPS) in December 2022.
In an emotional Instagram video, she told fans the condition had affected “every aspect of my daily life”.
Affecting an estimated 8,000 people worldwide, SPS is a neurological disease caused by the signals from the nerves to the muscles not working properly.
The condition causes muscle spasms and can affect mobility. For some, it can be debilitating. There is no known cure.
Speaking to the BBC in 2024, Dion said she had first noticed the symptoms when her voice played up on tour.
“It was just feeling a little strange, like a little spasm,” she said.
“My voice was struggling, I was starting to push a little bit.”
At the time, she felt it was impossible to take time off, and experimented with singing in a lower register to ease the stress on her vocal cords.
“These shows were sold out for a year and a half, going around the globe.
“And I’m going to say to people, ‘Excuse me about my spasm? Excuse me about my je ne sais quoi?'”
However, the condition worsened, “sometimes causing difficulties when I walk and not allowing me to use my vocal cords to sing the way I’m used to,” she told NBC News.
“It’s like somebody is strangling you. It’s like somebody is pushing your larynx [or] pharynx.”