In an emotional video posted to Instagram Thursday, Celine Dion announced that she has been diagnosed with a painful neurological disorder called Stiff Person Syndrome.
In the video, she said she's been dealing with symptoms for a while.
The condition forced the singer to postpone her upcoming European tour.
But what exactly is Stiff Person Syndrome?
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A doctor at Cedar Sinai Medical Center in Los Angeles who specializes in the disease explained.
The rare neurological disorder is an autoimmune condition that causes painful muscle spasms throughout the body.
In the video, Dion described it affecting her vocal cords, not allowing her to sing the way she's used to.
Dr. Michele Tagliati is the vice chairman of neurology at Cedars Sinai Medical Center in Los Angeles.
While he doesn’t treat Celine Dion, he treats other patients with Stiff Person Syndrome, which causes antibodies to attack the muscles.
"When these antibodies go into action, you lose control of your muscles and they go into terrible spasms, which can be quite debilitating," Tagliati said.
Tagliati says the 54-year-old singer’s condition is extremely rare, affecting only about one in a million people, and twice as many women as men, usually between the ages of 30 and 60.
Researchers are still looking for the cause of stiff person syndrome but medications can help alleviate symptoms.
It’s often misdiagnosed as Parkinson’s Disease but a blood test can detect 80% of cases.
The Grammy and Oscar award winning singer was receiving well wishes from around the world, including messages on Instagram from celebrities like Gwen Stefani, Kate Hudson, and Christie Brinkley.
Dion says she’s hoping she can get her symptoms under control and return return to the stage next year.
There is no cure for the condition.