Céline Dion experiences 'unimaginable' medical episode in new documentary. What to know about Stiff Person Syndrome

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Céline Dion has been experiencing Stiff Person Syndrome (SPS) symptoms for the last 17 years, and one scene in the Canadian icon's new documentary shows just how scary the rare neurological condition can be. Towards the end of "I Am: Celine Dion," which was released this week, the effects of the 56-year-old singer's life-changing condition are put on full display.

The gut-wrenching scene begins with Dion in a physical therapy session, shortly after she was seen recording a new song, "Love Again," according to TODAY. During her session, the "My Heart Will Go On" songstress appears to be performing her regular exercises with her physical therapist.

However, she suddenly suffers cramping in one of her legs, which then makes her whole body tense up. The medical episode becomes so serious that she can't speak, move or change her facial expression, which shows she's in pain. As the experience continues, Dion sheds tears in silence, and her therapist asks her to squeeze his hand if she can hear him. She remains motionless but ends up finding a way to indicate she's aware of what's happening.

Dion's physician, Dr. Amanda Piquet, gave the artist a benzodiazepine nasal spray, according to TODAY. The treatment is a depressant drug that relieves anxiety and muscle spasms, and it eventually helps Dion calm down enough that she can sit up and speak again.

"It was the most extraordinarily uncomfortable moment in my life, as a filmmaker but also as a mother, as a fellow human, because I didn't know what was happening," the movie's director, Irene Taylor, told TODAY host Hoda Kotb in a recent interview.

"I had this uncertainty whether to keep filming or not. But (Céline) gave me the strength to just keep going. We had been filming together for many months at that point, so she had really trained me, 'Just keep going. If I have to stop you, I'll stop you.'"

Taylor continued, saying Dion's body experienced something "unimaginable," and she "wasn't sure if she was aware" it was happening. "I wasn't sure if she was going to survive it. It's really hard to even sit next to her and talk out loud about it because it was very intense," she added. Dion replied, "I just want you to know that you did the right thing. I'm sorry that it was hard."

What is Stiff Person Syndrome (SPS)?

As per the Stiff Person Syndrome Foundation, the condition affects the central nervous system, specifically the brain and spinal cord. People with SPS "can be disabled, wheelchair-bound or bedridden, unable to work and care for themselves." The syndrome is characterized by muscle spasms and rigidity, severe stiffness and pain.

SPS patients also have a heightened sensitivity to stimuli such as noise, touch and emotional distress, which can set off the spasms.

While SPS is a rare disease, more people are affected than reported due to misdiagnoses. Overall, it can take up to seven years to identify.

SPS can often be mistaken for multiple sclerosis, Parkinson's, fibromyalgia, psychosomatic illness, anxiety, phobia and other autoimmune diseases.

How Stiff Person Syndrome (SPS) affects Celine Dion's singing voice

In an Instagram clip, the singer shared SPS had affected "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...I have to admit it's been a struggle," she said.

SPS affects the muscles near Dion's vocal cords, which may impact the sounds of her voice.

Dr. Marinos Dalakas, a professor of neurology at Thomas Jefferson University in Philadelphia, told CTV News last year several of his patients with SPS have ongoing muscle stiffness.

"When this affects the diaphragm or affects the laryngeal muscles or the vocal cord muscles, the voice becomes very thin, it doesn't come out strong, it is fragmented," he said.

"The singers might get the stiffness more and then because the voice is so important for them the spasms are focussed more there."

What are the signs and symptoms of Stiff Person Syndrome?

The typical symptoms of SPS include muscle rigidity, hyper-stiffness and "spasms in muscles of the trunk, including the back and limbs." The severity of the tremors is variable from episode to episode.

Moreover, the neurological disease has autoimmune features that can also include "debilitating pain, chronic anxiety" and muscle spasms "so violent they can dislocate joints and even break bones."

In the early stages of SPS, spasms and stiffness may be subtle and fluctuate on a daily basis. There can be periods when symptoms seem stable, while other times, they can be more noticeable and rapid.

At times, the muscle spasms may be brief, lasting minutes. However, they can also last hours or days.

Other key warning signs include changes in posture, increased stress and anxiety, and trouble breathing.

If you or someone you know is experiencing any of the above symptoms, contact your doctor or a medical professional as soon as possible.

Who is at risk of Stiff Person Syndrome?

SPS is extremely rare and affects twice as many women as men. Symptoms can occur at any age but usually develop between ages 30 and 60.

The condition is usually associated with other autoimmune diseases such as vitiligo, diabetes, pernicious anemia and thyroiditis.

As a whole, health professionals are unsure what exactly causes SPS, but some research indicates it's the result of a faulty autoimmune response in the spinal cord and brain.

How is Stiff Person Syndrome treated?

Currently, there is no cure for SPS. Treatment focuses on pain relief and symptom management associated with muscle spasms, such as physiotherapy, a stretching and strengthening program and massage therapy.

In some patients, immunotherapy and other medications may help to reduce stiffness, pain and specific autoimmune abnormalities. That said, most people with SPS have at least some degree of disability.

If depression and anxiety are present, mental health therapy is encouraged, along with visiting a pain and chronic illness centre for regular check-ups.

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