DIAGNOSTIC TEST PANEL 568
Stiff Person Syndrome
Diagnostic test panel for antibodies against GAD, Amphiphysin, and GlyR. For suspicion of Stiff Person Syndrome.
Background
Stiff-person syndrome (SPS) is a rare neurologic disorder with autoimmune features. It is characterized by progressive, severe muscle rigidity or stiffness most prominently affecting the spine and lower extremities.
Clinical background
Stiff person syndrome, formerly stiff man syndrome, was first described in 1956 by two American doctors, Frederick P Moersch and Henry W. Woltman. It is a neurological condition that is characterized by progressive (progressive), muscle stiffness, painful muscle spasms and sometimes involuntary muscle twitching. A link between stiff person syndrome, type 1 diabetes mellitus (T1D) and epilepsy was described by Michele Solimena, professor of medicine at the University of Dresden, 1988.
International studies reports a prevelance of approximately one person per million population. The syndrome is probably underdiagnosed.
Cause of disease / injury
Stiff person syndrome is an idiopathic condition, ie, a disease whose root causes are unknown. An imbalance between stimulation and inhibition of GABA neurons is believed to cause the symptoms which leads to uncontrolled stimulation and thus muscle contraction (spasm). GABA is found not only in the nervous system but also in, for example, pancreatic insulin-producing islet cells and the adrenal glands. GABA is chemically (synthesized) from amino acid glutamate via a chain of enzymes, where one of these, GAD (Glutamic Acid Decarboxylase) is influenced in Stiff person syndrome.
Lack of GABA in inhibitory neurons may have different causes in which autoimmunity is considered to be a contributing factor. Autoantibodies to GAD and other substances that affect the transmission of signals between nerve cells have been shown to be associated with Stiff person syndrome. The presence of autoantibodies may sometimes be part of a paraneoplastic syndrome. This means that the symptoms and autoantibodies (e.g. directed against GAD or amphiphysin) occur adjacent to a malignant tumor. There mey be more yet undiscovered autoantibodies that affect GABA levels, thus signaling between nerve cells.
The presence of anti-GAD antibodies are not specific for Stiff person syndrome. It is also typical for people with type 1 diabetes mellitus, but only a few of these develop stiff person syndrome.
The syndrome can be divided into different types according to which muscle groups affected and severity:
- Stiff trunk syndrome (classically stiff person syndrome)
- Stiff limb syndrome
- Jerking Stiff person syndrome
- Progressive encephalomyelitis with rigidity and myoclonus (PERM)
The diagnosis is made on the basis of typical symptoms. In most patients with the syndrome, specific antibodies directed against GAD can be detected in both blood and in the cerebrospinal fluid. Other antibodies can also be found where amphiphysin and glycine receptor antibodies are available for diagnostic use.
There may be a link to other autoimmune diseases, such as diabetes mellitus type 1, Hashimoto thyroiditis (thyroid inflammation), poor pigment spots in the skin (vitiligo) and certain types of anemia (pernicious anemia).
The diagnosis of the syndrome should be followed with investigation for a tumor. Especially breast cancer is linked to the syndrome, but also gastric cancer, small cell lung cancer and Hodgkin's lymphoma (lymph node cancer) have been associated with the symptom. Patients with Stiff person syndrome and breast cancer have usually not anti-GAD autoantibodies to the same extent as others with the syndrome, but instead autoantibodies to amphiphysin.
References
- Alexopoulos H, Dalakas MC. A critical update on the immunopathogenesis of stiff person syndrome. Eur J Clin Invest 2010; 40: 1018-1025.
- Brown P, Marsden CD. The stiff man and stiff man plus syndromes. J Neurol 1999; 246: 648-652.
Tests included in panel
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How to order
This test panel is available worldwide for hospitals, clinics, and physicians.
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Print and complete the request form
Download the request form. Clearly state the name and phone number of the referring hospital, clinic, or physician. -
Prepare your samples
Serum: At least 1 mL serum (plain serum tubes without additives).
CSF: At least 2.5 mL CSF (polypropylene tubes).
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Send samples and request form
Within Sweden
Samples can be sent at room temperature to:
Envelopes and smaller boxes:
Wieslab AB, Box 50117, 20211 Malmö, Sweden
Larger boxes and frozen samples:
Wieslab AB, Lundavägen 151, 21224 Malmö, Sweden
International
Send samples cold to:
Wieslab AB, Lundavägen 151, 21224 Malmö, Sweden
Last updated: 2025-08-18
