Superstar singer Celine Dion has called off a major European tour as she fights an ultra-rare medical condition called stiff person syndrome, which causes extreme muscular rigidity and painful spasms. Dion first called a halt to her Courage World Tour last December but hoped to get on the road again in Europe this year. She has now been forced to cancel 42 dates in 24 cities, starting in Amsterdam this August and ending in London next April. “Even though it breaks my heart, it’s best that we cancel everything until I’m really ready to be back on stage,” Dion said. “I’m not giving up… and I can’t wait to see you again!”