About Stiff Person Syndrome

Whether this is the first time you’ve heard of Stiff Person Syndrome, or you’ve been a part of the community for some time now, you can find more information and resources about the condition here.

What Do You Need To Know
About Stiff Person Syndrome?

Stiff Person Syndrome (SPS) is a rare autoimmune disorder (where your body mistakenly attacks its own cells) that impacts the nervous system. It causes progressive stiffness and spasms in the muscles – In the early stages, you may experience stiffness that comes and goes. This could involve areas like your shoulders, arms, and, less often, your face. As the condition advances, leg stiffness can develop, and it might affect one side of your body more than the other. This could result in a slow, stiff way of walking.

Over time the disorder causes multiple muscles to activate at the same time, particularly in the abdomen and back affecting the posture and balance. As the condition progresses, the rigidness can spread to the limbs, making it difficult to walk, and in some cases, prevent walking entirely. Less common SPS symptoms include breathlessness, facial spasms, or appetite changes, potentially caused by medication side effects. While this condition can affect anyone, it tends to affect women more than men.

Since SPS causes muscle stiffness and painful muscle spasms, this condition is often misdiagnosed as Parkinson’s disease, Multiple Sclerosis, Fibromyalgia, Polyneuropathy, Ankylosing spondylitis or a psychosomatic illness. A definitive diagnosis of SPS can be made with a blood test that measures the level of glutamic acid decarboxylase (GAD) antibodies.

Types and Symptoms

Classic Stiff Person Syndrome

Progression is slow and gradual. It often causes stiffness and painful spasms in the muscles in the legs and torso, and it may affect one side of the body more than the other. Rigidity can also cause an arched lower back. muscle spasms often is exacerbated by loud or sudden noises

Focal Stiff Person Syndrome affects specific areas of the body, typically causing leg stiffness, spasms and jerking.  As the condition progresses, other muscles like the trunk can also be affected, progressing to symptoms such as the classic type

Progressive Encephalomyelitis with Rigidity and Myoclonus (PERM) 

The symptoms are similar to SPS, such as muscle stiffness and spasms, but progression is quicker and more severe. Encephalomyelitis refers to a condition that affects your brain and spinal cord.As such, PERM also involves symptoms such as 

dizziness, lack of muscle coordination, speech difficulties, confusion, or seizures. This form also affects the body’s ability to regulate vital functions like blood pressure, heart rate, and temperature.

Paraneoplastic Stiff Person Syndrome 

It’s one the rarest types of SPS. It involves tumors, some of which may be cancerous, of the thymus, colon, lung, breast, ovary, and less frequently, of the lymphatic system.

Stiff Person Syndrome with Cerebellar Ataxia 

This type includes symptoms of muscle incoordination, a condition known as cerebellar ataxia. If you have this, you might find it difficult to coordinate your movements while walking. You may also experience unusual eye movements, persistent double vision, and feelings of vertigo or dizziness.

In addition to mobility symptoms, individuals with SPS often experience fear of falling, leading to anxiety and unwillingness to leave home. Chronic pain and reduced mobility can cause depression and anxiety. 

Potential Breathing Issues: Less common SPS symptoms include breathlessness, facial spasms, or appetite changes, potentially caused by medication side effects.

Rare Concierge

Try our free one-on-one service for patients looking for information and resources on their rare disease.

Stay Connected

Sign up for updates straight to your inbox.



Diagnosis can be difficult and misdiagnosis for other conditions such as Parkinson’s disease, multiple sclerosis, fibromyalgia, psychological issues, or anxiety disorders are common. The correct diagnosis can be made via a blood test that checks for something called glutamic acid decarboxylase (GAD) antibodies. Most people with SPS have very high levels of GAD antibodies in their blood or spinal fluid. 

Other tools used by doctors to diagnose SPS involve:

  • assessing stiffness in the limbs and torso, specifically in the abdomen and lower back region.
  • EMG (Electromyography), a test that measures muscle response
  • Other tools like MRI and CT scans can be used to rule out other causes for the symptoms
  • For the Paraneoplastic type, a doctor may check for cancer signs
  • Sometimes, people with SPS also have other autoimmune conditions. So part of diagnosing SPS includes checking for these conditions too.


There is no cure for SPS, and treatment involves addressing specific symptoms seen in each person. Those can involve both medicated with prescribed muscle relaxants, and non-medication treatments, such as stretching, heat therapy, aqua therapy, massage therapy, acupuncture, balance training, behavioral therapy, physical therapy, yoga, and meditation.

Immunotherapy may also be recommended, as well as mental health therapies. Any treatment should only be started after a thorough discussion of the possible risks and benefits with a medical provider. Information on current clinical trials can be found at

My Name is Jennifer. I Have Stiff Person Syndrome (SPS)

My “odd” neurological journey began shortly after my 40th birthday.  Excruciating pain and stiffness; numbness; tremors and an exaggerated startle reflex were just a few of my symptoms. Deep down, I knew that something was destroying my body, despite being told by physicians they “could not find anything medically wrong with me.”

Although SPS causes daily pain, stiffness and has slowed me down, I continue to fight the good fight with faith, family, a close circle of friends and my career. I’ve learned to live one minute at a time and to focus on what really matters because life is short.

Read Jennifer’s Story

A 1-In-A-Million Rare Disease Called Stiff Person Syndrome

I am a doctor, but I feel like I am able to do so little for my sister.

My sister Laura has a rare disease called Stiff Person Syndrome. It affects only one in one million individuals, worldwide. It is considered a neurological disease, but it is often classified as an autoimmune disease, characterized by alternating rigidity and spasticity of the muscles, tremors, anxiety and a hyper-excitability of muscles. Emotional stress or even a gentle touch, are known to cause prolonged, often severe, spasms.

A Sister’s Fight

Need More Resources or Have Questions?

Patient Advocacy Groups That Can Help

The Global Advocacy Alliance is a global community of non-profit organizations and support groups who are committed to changing the way the world tackles rare diseases. This group of non-profit and rare disease support groups can provide resources and answer questions specific to Stiff Person Syndrome or related conditions like the ones listed above.

Rare Disease Facts

RARE Diseases Impact More People Than
Cancer and AIDS Combined

1 in 10

People are Affected by Rare Disease

1 in 2

Rare Diseases Don’t Have a Foundation or Research Support Groups

1 of 2

Patients Diagnosed with a Rare Disease is a Child

3 of 10

Children with a Rare Disease Won’t Live to See Their 5th Birthday


Million People Suffer From a Rare Disease Globally

8 in 10

Rare Diseases are Genetic

6+ Years

The Average Time it Takes for Rare Patients to Receive an Accurate Diagnosis


of Rare Diseases Lack an FDA Approved Treatment


Distinct types of Rare and Genetic Diseases

Up to $517,000

The economic impact of a delayed diagnosis is up to $517,000 in avoidable costs per patient.

Celebrities with Rare Diseases

Interest in rare diseases often increases when celebrities discuss their diagnosis, or the diagnosis of a loved one, publicly.

No one living with a rare disease would wish it upon another person. But many people with a rare disease that is made worse by being too little known or discussed will find themselves wishing a famous celebrity would take up their cause. It’s easy to imagine all the media attention that might shine on your disease if Selena Gomez or Justin Beiber talked about it.  But in reality, celebrities tend not to take up rare disease causes unless it affects them directly or someone close to them.

Images courtesy of IMDB

Learn more