Céline Dion has canceled all her scheduled tour dates through April 2024 as she continues treatment for a rare neurological disorder.

“I’m so sorry to disappoint all of you once again,” the singer said in a statement on social media. “I’m working really hard to build back my strength, but touring can be very difficult even when you’re 100%. It’s not fair to you to keep postponing the shows, and even though it breaks my heart, it’s best that we cancel everything now until I’m really ready to be back on stage again.

A total of 42 European dates have been canceled, including stops in the Netherlands, France, Belgium, Denmark, Norway, Sweden, Finland, Poland, Czech Republic, Switzerland, Croatia, Germany, Hungary, Austria, England, Scotland and Ireland.

Earlier this year, Dion said stiff person syndrome was causing spasms that affect her ability to walk and sing.

“Unfortunately, the 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.

Stiff person syndrome causes rigid muscles and painful muscle spasms, which can be triggered by such things as loud noises or light touch. The cause isn’t known, but it is thought to be an autoimmune disorder. Severe cases can cause difficulty walking and hunched posture.

Dion, who has five Grammy Awards and two Academy Awards, is the bestselling female artist of all time with hits like “I’m Alive” and “My Heart Will Go On.”