Celine Dion’s shock diagnosis: What is stiff-person syndrome and what are the symptoms?

Celine Dion revealed the devastating diagnosis will keep her from embarking on tour in February. Photo / Getty Images

Pop icon Celine Dion’s stiff-person diagnosis has brought awareness to the rare condition, which affects about one or two out of every million people.

The star announced earlier today that she had postponed her 2023 European tour due to the diagnosis causing “difficulties when I walk and not allowing me to use my vocal cords to sing the way I’m used to”, as she revealed in an Instagram video.

So, what exactly is the condition - and why, as in Dion’s case, is it incurable?

People with the condition tend to experience stiffness in their limbs and torso, and severe muscle spasms which can occur randomly or be triggered by noise, touch or emotional distress.

Yale School of Medicine assistant neurology professor Dr Richard Nowak told NBC that the condition can range from “quite mild - easily managed with a little bit of medication - to folks that are quite severe that can be, frankly, quite disabled from it”.

That’s because it interrupts the usual communication pathways between the muscles and the brain, he explained.

“There’s a massive firing that’s occurring from the central nervous system, down through the spinal cord, down through the nerves as they plug into the muscles, and it’s causing them to become rigid or go into spasm, which equals the stiffness.”

Harvard Medical School rheumatologist Dr Simon Helfgott described the condition as “losing your brakes on your muscles”.

“Once your muscle starts to contract, it doesn’t have a way to stop itself from contracting,” he told the outlet.

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Symptoms don’t just involve muscle cramps, which we can all experience on occasion, Helfgott said. Instead, the muscles completely lock up and can cause difficulty walking, with some patients even needing wheelchairs.

“This is just such a severe diagnosis to have, especially if you’re an entertainer [on] the world-class type of stage,” he told NBC.

“It’s going to be very, very challenging to be able to continue.”

The syndrome is more difficult to treat than similar disorders like Crohn’s disease or rheumatoid arthritis, and it is incurable.

It can be treated with muscle relaxants or Botox to relieve the spasms, with some patients prescribed intravenous immunoglobulin to reduce stiffness and sensitivity to touch, noise and stress.

But Helfgott said it’s hard to predict whether the condition will get worse as time passes.

“In some cases, the condition can level off and stay the way it is. I have people who are like that — they’re no different now than they were 10 years ago ... in others, it is a slow, subtle decline.”