Stiff person syndrome (SPS) is a rare, progressive disease that affects the nervous system, specifically the brain and spinal cord. The syndrome affects twice as many women as men. SPS is caused by increased muscle activity due to decreased inhibition of the central nervous system. It is thought to have an autoimmune component and is often associated with diabetes, as well as other autoimmune diseases.

 


Lea Jabre Fayad, founder of Bent Not Broken, Heart to Heart, and patient with SPS, describes her personal journey with the disease. For information on her fundraiser with Johns Hopkins, click here.

Etiology

The exact cause of SPS is unknown. Research indicates a possible link between SPS and an incorrect autoimmune response in the brain and spinal cord. The disease is frequently associated with other autoimmune diseases including type 1 diabetes, thyroiditis, vitiligo, and anemia.

 

Signs and Symptoms

Symptoms may include extreme muscle stiffness, rigidity and painful spasms in the trunk and limbs, severely impairing mobility. Spasms may generate enough force to fracture bone. People with SPS often have heightened sensitivity to noise, sudden movements, and emotional distress, which can set off muscle spasms. Persistent symptoms can lead to abnormal posturing of the spine, such as being hunched over. 

 

Diagnosis

SPS may be diagnosed after having various tests including tests for associated antibodies in serum and cerebrospinal fluid (CSF) and blood tests (such as for glutamic acid decarboxylase (GAD) antibodies which is elevated in about 2 in 3 people with SPS), a lumbar puncture, and electromyography. Spinal cord scans can help to exclude mechanical causes such as a cyst or disc compression of the spinal cord.

 

Management Strategies and Treatment

Current management of SPS involves a focus on symptom management. Benzodiazepines and baclofen are standard drugs for symptomatic treatment of muscle spasms. intravenous immunoglobulin treatment has shown effectiveness in reducing stiffness, sensitivity to noise, touch, and stress, and for improving gait and balance.

 

Clinical Trials and Studies

For a full list of clinical trials relating to stiff person syndrome, click here.

 

Resources

The Stiff Person Syndrome Research Foundation

 

References

Stiff person spectrum disorder. In: Orphanet [Internet]. Available at https://www.orpha.net/en/disease/detail/3198

Stiff-Person Syndrome. National Institute of Neurological Disorders and Stroke. Available at https://www.ninds.nih.gov/health-information/disorders/stiff-person-syndrome#:~:text=Stiff%2Dperson%20syndrome%20(SPS),can%20set%20off%20muscle%20spasms

 

For more information on rare neurological disorders, visit https://checkrare.com/diseases/neurology-nervous-system-diseases/