A former marathon runner who was himself diagnosed with stiff-person syndrome says Celine Dion's comeback tour could be a trigger for the rare condition.

Céline Dion won the week last week (along with two other celebs) after she made her huge, internet-breaking announcement: She's returning to the concert stage. On March 30, Dion posted a video

Dion is currently battling a serious neurological condition called stiff person syndrome. Here's what we know.

Celine Dion turned 58 years old on March 30, and according to sources, she's been 'gently rehearsing' over the past year.