Stiff Person Syndrome

National Organization for Rare Disorders, Inc.

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It is possible that the main title of the report Stiff Person Syndrome is not the name you expected.

Disorder Subdivisions

  • None

General Discussion

Stiff-person syndrome (SPS) is a rare acquired neurological disorder characterized by progressive muscle stiffness (rigidity) and repeated episodes of painful muscle spasms. Muscular rigidity often fluctuates (i.e., grows worse and then improves) 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. In most cases, other neurological signs or symptoms do not occur. The severity and progression of SPS varies from one person to another. If left untreated, SPS can potentially progress to cause difficulty walking and significantly impact a person's ability to perform routine, daily tasks. Although the exact cause of SPS is unknown, it is believed to be an autoimmune disorder and sometimes occurs along with other autoimmune disorders.

Stiff-person syndrome has been described in the medical literature under many different, confusing names. Originally described as stiff-man syndrome, the name was changed to reflect that the disorder can affect individuals of any age and of either gender. In fact, most individuals with the condition are women. Stiff-person syndrome is considered by many researchers to be a spectrum of disease ranging from the involvement of just one area of the body to a widespread, rapidly progressive form that also includes involvement of the brain stem and spinal cord (progressive encephalomyelitis with rigidity and myoclonus).

Supporting Organizations

American Autoimmune & Related Diseases

22100 Gratiot Ave.
Eastpointe, MI 48021
Tel: (586)776-3900
Fax: (586)776-3903
Tel: (800)598-4668

AutoImmunity Community


Genetic and Rare Diseases (GARD) Information Center

PO Box 8126
Gaithersburg, MD 20898-8126
Tel: (301)251-4925
Fax: (301)251-4911
Tel: (888)205-2311

Living With Stiff Person Syndrome

Tel: 904-375-9385

Movement Disorder Society

555 E. Wells Street
Suite 1100
Milwaukee, WI 53202-3823
Tel: (414)276-2145
Fax: (414)276-3349

NIH/National Institute of Neurological Disorders and Stroke

P.O. Box 5801
Bethesda, MD 20824
Tel: (301)496-5751
Fax: (301)402-2186
Tel: (800)352-9424

Stiff Man Syndrome Support group

75 Normandy Avenue
East Yorkshire, HU17 8PF
United Kingdom
Tel: 1482868881

Stiff Person Syndrome.Net

5667 Swamp Fox Rd.
Jacksonville, FL 32210
Tel: (904)771-9185
Fax: (904)771-5491

For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders (NORD). For a full-text version of this report, go to and click on Rare Disease Database under "Rare Disease Information".

The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only.

It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report.

This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

Last Updated:  7/13/2010
Copyright  2010 National Organization for Rare Disorders, Inc.