(Reuters) – Canadian pop singer Celine Dion said on Friday she had canceled the European leg of her world tour, which was due to resume this summer, due to a medical condition that made it difficult to perform.

The announcement comes four months after the 55-year-old singer said she was diagnosed with a rare neurological disorder called stiff-person syndrome, which causes muscle spasms. At the time, the disruption forced her to postpone some European shows from her “Courage World Tour”.

“I’m so sorry to let you down yet again,” the singer – best known for the ‘Titanic’ theme song “My Heart Will Go On” wrote on Instagram Friday morning.

“I’m working very hard to regain my strength, but touring can be very difficult even when you’re at 100 per cent.”

The European leg of the tour included 42 shows in seven cities from late August to early October and another 17 cities in spring 2024. Dion said ticket holders will receive refunds.

Stiff-person syndrome causes muscle stiffness and increased sensitivity to sound, touch, and emotional stimuli that can trigger spasms. The condition led the Grammy winner to postpone performances in Las Vegas to October 2021.

The tour – his first in the United States in 10 years – began in Quebec in September 2019. It was accompanied by the release of his latest album “Courage”.

The singer said the title of the album was inspired by the death of her husband and manager, René Angélil, in 2016 from throat cancer. The couple had three children.

(Reporting by Brendan O’Brien in Chicago; Editing by Brendan O’Brien)