What is Stiff-Person Syndrome?
Stiff-person syndrome (SPS) is a rare neurological
disorder with features of an autoimmune disease. SPS is characterized by
fluctuating muscle rigidity in the trunk and limbs and a heightened sensitivity
to stimuli such as noise, touch, and emotional distress, which can set off
muscle spasms. Abnormal postures, often hunched over and stiffened, are
characteristic of the disorder. People with SPS can be too disabled to walk or
move, or they are afraid to leave the house because street noises, such as the
sound of a horn, can trigger spasms and falls. SPS affects twice as many women
as men. It is frequently associated with other autoimmune diseases such as
diabetes, thyroiditis, vitiligo, and pernicious anemia. Scientists don’t yet
understand what causes SPS, but research indicates that it is the result of an
autoimmune response gone awry in the brain and spinal cord. The disorder is
often misdiagnosed as Parkinson’s disease, multiple sclerosis, fibromyalgia,
psychosomatic illness, or anxiety and phobia. A definitive diagnosis can be made
with a blood test that measures the level of glutamic acid decarboxylase (GAD)
antibodies in the blood. People with SPS have elevated levels of GAD, an
antibody that works against an enzyme involved in the synthesis of an important
neurotransmitter in the brain.
Is there any treatment?
People with SPS respond to high doses of diazepam and
several anti-convulsants, gabapentin and tiagabine. A recent study funded by the
NINDS demonstrated the effectiveness of intravenous immunoglobulin (IVIg)
treatment in reducing stiffness and lowering sensitivity to noise, touch, and
stress in people with SPS.
What is the prognosis?
Treatment with IVIg, anti-anxiety drugs, muscle
relaxants, anti-convulsants, and pain relievers will improve the symptoms of SPS,
but will not cure the disorder. Most individuals with SPS have frequent falls
and because they lack the normal defensive reflexes; injuries can be severe.
With appropriate treatment, the symptoms are usually well controlled.
What research is being done?
The National Institute of Neurological Disorders and
Stroke (NINDS) conducts research related to SPS in its laboratories at the
National Institutes of Health (NIH), and also supports additional research
through grants to major medical institutions across the country. A study using
the drug rituximab proved ineffective in treating individuals with the disorder.
Current research is focused on understanding the cause of the disease and the
role of the anti-GAD antibodies.
National Rehabilitation Information Center (NARIC)
8201 Corporate Drive, Suite 600
Landover, MD 20785
Tel: 301.459.5900/301.459.5984 (TTY) 800.346.2742
National Organization for Rare Disorders (NORD)
P.O. Box 1968
(55 Kenosia Avenue)
Danbury, CT 06813-1968
Tel: 203.744.0100 Voice Mail 800.999.NORD (6673)
National Institute of Arthritis and Musculoskeletal
and Skin Diseases (NIAMS)
National Institutes of Health, DHHS
31 Center Dr., Rm. 4C02 MSC 2350
Bethesda, MD 20892-2350
Tel: 301.496.8190 877.22.NIAMS (226.4267)
Source: National Institutes of Health; National Institute of Neurological Disorders and Stroke
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 11/15/2010...#6076