Stiff person syndrome is a rare neurological condition that can take years to diagnose and have treatment plans tailored.
Singer Celine Dion, 54, announced in an Instagram video on Thursday (local time) that she is cancelling performances due to being diagnosed with the condition.
"While we're still learning about this rare condition, we now know this is what's been causing all of the spasms that I've been having," Dion said.
What is stiff person syndrome?
Stiff person syndrome is characterised by muscle rigidity and spasms, heightened sensitivity to stimuli such as sound and lights, and emotional distress that can cause muscle spasms, according to the National Institute of Neurological Disorders and Stroke.
"It frequently is associated with muscle spasms, which could be quite severe. These can cause falls, severe pain and significant disability," said Dr Emile Sami Moukheiber of the Stiff Person Syndrome Center at Johns Hopkins Medicine.
"Falls from severe spasms are very common. These spasms can be precipitated by startle, severe emotions, cold weather."
These spasms can be strong enough to fracture bone, and any fall can lead to severe injury.
Dion said in her video that spasms affect "every aspect" of her 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."
The syndrome's symptoms can also cause anxiety.
"Many patients, if not all, have an anxiety that is intrinsic to the disease and that anxiety actually feeds on the physical ailments of the disease that people can have," Dr Scott Newsome, director of the Stiff Person Syndrome Center, said in a video on the organisation's website.
Who is affected by stiff person syndrome?
The condition affects about one a million people, and most general neurologists will see only one or two cases in their lifetimes, Moukheiber said.
The first case of stiff person syndrome was reported in the 1950s, according to Newsome, and the disease was historically referred to as "stiff man syndrome."
Since then, it has been found to affect twice as many women than men, and the name was changed to stiff person syndrome to avoid confusion.
What causes stiff person syndrome?
Stiff person syndrome is thought to have features of an autoimmune disease, according to the National Institute of Neurological Disorders and Stroke.
Although the exact cause isn't clear, according to the institute, "people with SPS have elevated levels of GAD, an antibody that works against an enzyme involved in the synthesis of an important neurotransmitter in the brain."
Because of the rarity of the disease and the ambiguity of its symptoms, people will often seek care for chronic pain before they get neurological care. On average, it takes about seven years for someone to receive a diagnosis of stiff person syndrome, Newsome says.
"Sometimes, [patients] get labelled crazy," he said, "because on exam early on, there aren't the hallmark features of stiff person syndrome."
How is stiff person syndrome treated?
There is no known cure for stiff person syndrome, but medications can ease the symptoms. Immunoglobulin medications can help lower sensitivity to light or sound triggers, potentially helping head off falls or spasms.
Pain relievers, anti-anxiety medications and muscle relaxers can be a part of treatment for this disease. The Stiff Person Syndrome Center also uses botulinum toxin injections.
"If left untreated, the disease can cause severe impairment of daily living," Moukheiber said.
But with treatment, symptoms can be controlled.
Dion, who said she has struggled with her health for a while, said she has a great team of medical professionals and her children's support.
"I'm working hard with my sports medicine therapist every day to build back my strength and my ability to perform again," she said. "But I have to admit it's been a struggle."
For a performer like Dion, loud noises and bright lights could act as triggers to muscle spasms.
"This is a very challenging illness that might take a toll on her if it is not treated aggressively, timely and appropriately," Moukheiber said.
CNN
