All You Need to Know About Stiff Person Syndrome

In December 2022, Grammy award-winning singer Celine Dion gave stiff person syndrome a new voice after her shocking revelation that she was diagnosed with the rare disease.

For close family members and friends, the news was no surprise. Dion had been suffering from mysterious symptoms for several years that caused muscle tightness, spasms and stiff limbs that eventually affected her ability to perform and sing on stage. In a publicly released video, Dion emotionally shared the news and explained how the muscle spasms affected “every aspect” of her life and led her to cancel her music tour.

“It takes real courage to go public with personal health issues — perhaps even more so when the diagnosis is a largely unfamiliar condition that carries a decidedly unusual name and impacts only about 1 in every 1 million people,” says Tara Zier, founder of the Stiff Person Syndrome Research Foundation, who was diagnosed with the condition in 2017.

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What Is Stiff Person Syndrome?

Considered a rare and progressive neurologic condition, stiff person syndrome (SPS) doesn’t just cause stiff muscles.

“The disease name really doesn’t do it justice and is quite misleading because it is more than stiff muscles and comes with constant debilitating pain and fatigue,” Zier says.

SPS is characterized by progressive muscle stiffness (rigidity) and repeated episodes of painful muscle spasms. Muscular rigidity often fluctuates and usually occurs along with the muscle spasms. Spasms may occur randomly or be triggered by a variety of different events, including a sudden noise or light physical contact. It takes about seven years for people to get an accurate diagnosis. Typically, neurologists with a subspecialty in neuroimmunology, neuromuscular or movements disorders, diagnose and treat people with the condition.

The severity and progression of SPS varies from one person to another. If left untreated, SPS can potentially progress to cause difficulty walking and can significantly impact a person’s ability to perform routine, daily tasks, according to the National Organization for Rare Disorders. In severe cases, some people may be bedridden or bound to a wheelchair.

“SPS can affect people in many ways and can negatively affect quality of life,” says Dr. Scott Newsome, director of the Stiff Person Syndrome Center at Johns Hopkins Medicine in Baltimore.

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Types of SPS

SPS varies from mild to severe, but if untreated, it can be progressive and disabling. There are several types of SPS with distinct physical and clinical differences. The different types include:

Classic SPS: This is the most common type of SPS. Symptoms of classic SPS include muscle rigidity, stiffness and spasms in muscles of the trunk, especially the back and limbs. Muscle spasms vary greatly in intensity and duration, but they often become worse over months or years. As a result of the muscle spasms, especially if there are continuous contractions in the back and stomach muscles, some people develop an exaggerated sway back posture.

Focal SPS or partial SPS: In some people with SPS, the muscle stiffness and spasms might only be in a limb, usually one leg, though it may be in both legs. There may also be leg jerking. Walking may become increasingly difficult. Eventually the trunk muscles may also become involved, similar to classic SPS symptoms.

Paraneoplastic SPS: This is a rare form of SPS characterized by autoimmune antibodies associated with tumors that may or may not be cancerous. Tumors associated with SPS include those of the thymus, colon, lung, breast and ovary. However, most people with SPS do not develop cancerous tumors.

Progressive encephalomyelitis with rigidity and myoclonus (PERM): This type of SPS is more severe, usually associated with rapid deterioration because it impacts the brain and spinal cord. Encephalomyelitis means a disease which impacts the brain and spinal cord. This form of SPS may include irregular muscle contractions, abnormal eye movements, seizures, cognitive and behavior changes, difficulty swallowing, along with problems regulating blood pressure, heart rate and body temperature.

SPS with cerebellar ataxia: This type of SPS has an overlap with cerebellar ataxia, which indicates people have muscle incoordination. They may have ataxia with walking, and may have abnormal eye movements, persistent double vision, vertigo and dizziness.

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Signs and Symptoms

There is an expanding spectrum of signs and symptoms that are seen in those with SPS. Symptoms can be triggered by stress, cold and unexpected loud noises that can temporarily increase stiffness and spasms, leading to balance problems and falls.

“SPS can be misdiagnosed as another movement disorder, neuroinflammatory conditions and even rheumatologic disorders,” says Dr. Duarte Machado, director of the Chase Family Movement Disorders Center in Cheshire, Connecticut. There are several conditions that can mimic SPS based on symptoms and signs, including multiple sclerosis, fibromyalgia, Parkinson’s disease, motor neuron disease, functional neurological disorder and other autoimmune diseases.

In the classic form of SPS, the most common symptoms may include:

— Back and stomach muscle tightness.

— Balance issues.

Muscle spasms.

— Pain throughout the body.

— Rigidity.

— Spasticity.

— Stiffness in the torso and limbs.

— Twitching.

With ongoing back and stomach muscle contractions that cause spasms, people can develop changes to their spine and posture, including:

— Curvature of the lumbar spine (hyperlordosis).

Hunched posture (kyphosis).

— Sway back posture (lordosis).

The classic symptoms of SPS can also occur in the other types of SPS. People who have the other types will also experience symptoms that localize to the brainstem and/or cerebellum. For example, some people will have double vision, vertigo, swallowing problems, incoordination and other non-classic symptoms.

Risk Factors for SPS

There are no known risk factors associated with SPS. However, just like other autoimmune conditions, some people have reported experiencing an emotional or traumatic event or major infection leading up to their initial symptoms.

While the disorder may affect children, signs of SPS typically first appear in middle age. SPS affects women twice as often as men, which is why the original disease name — stiff man syndrome — was changed to stiff person syndrome in the early 1990s. The mean age of diagnosis is 41 years old, ranging from 7 to 75 years old, according to Machado.

“At this time, it is not clear whether specific races or ethnicities are at greater risk to develop SPS,” Newsome says.

Medication and Management

There are currently no medications specifically approved by the Food and Drug Administration to treat SPS. Available treatments focus on symptom management, particularly pain and muscle spasm relief with the primary goal of preventing worsening and progressing symptoms.

The most common treatments include:

Benzodiazepines: The most commonly prescribed benzodiazepine is Valium, which is often used to help manage stiffness and painful spasms.

Immune-based therapies: These treatments are used to calm down the immune system to lessen spasms. The preferred treatment is intravenous immunoglobulin (IVIG), but it comes with serious side effects. Newer immunomodulating agents are being studied to treat difficult cases and produce longer remissions with fewer side effects.

Monoclonal antibodies: Rituximab (Rituxan) is used to treat a number of autoimmune diseases such as SPS. One published report of an individual experience taking rituximab showed a positive long-term benefit.

Muscle relaxants: Baclofen is prescribed to control muscle spasms. Sometimes baclofen is delivered intravenously into the spine for more immediate relief.

Non-medication interventions: To help manage muscle spasms and pain, some people turn to physical rehabilitation, aqua therapy, acupuncture, dry needling, massages, stretching and heat therapy. One study showed that treatment with physical therapy was a beneficial intervention in people with SPS.

“A new treatment being investigated is stem cell transplantation, specifically autologous hematopoietic stem cells,” Machado says. “Clinical trials have shown that stem cell transplants are safe, but the beneficial effect is variable, so more data needs to be obtained.”

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All You Need to Know About Stiff Person Syndrome originally appeared on usnews.com

Update 04/07/23: A previous version of this story incorrectly stated when Tara Zier was diagnosed with stiff person syndrome. She was diagnosed in 2017.

Update 06/15/23: This piece was previously published at an earlier date and has been updated with new information.

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