Dion shared that she had been diagnosed with a “very rare” progressive neurological disorder called stiff-person syndrome, surely the first time that most people had ever heard of it.

“As you know, I’ve always been an open book,” she said in an Instagram video. “I wasn’t ready to say anything before, but I’m ready now. I’ve been dealing with problems with my health for a long time, and it’s been really difficult for me to face these challenges and to talk about everything that I’ve been going through.”

She suffered muscle spasms that affected “every aspect” of her daily life, Dion explained, making it difficult to walk sometimes and, saddest of all, it was going to be impossible for her to go back on tour as she’d been planning.

“I’m working hard with my sports medicine therapist every day to build back my strength and my ability to perform again,” Dion said. “But I have to admit, it’s been a struggle.”

According to the National Institutes of Health, symptoms include stiff muscles in the torso, arms, and legs, and greater sensitivity to noise, touch, and emotional distress, all of which can trigger muscle spasms.