The Process

The classical Stiff Person Syndrome is associated with a number of other diseases. The most common of these is insulin-dependent diabetes mellitus. Also reasonably common are the co-existence of thyroid disease, vitiligo and pernicious anaemia. All these diseases have in common an autoimmune (self-allergic) nature and it is likely that the Stiff Person Syndrome has a similar basis. There are some variants of the Stiff Person Syndrome, which have been more recently recognised. The first of these, sometimes called the Stiff Limb Syndrome, is similar but painful spasms and occasionally fixed deformities, affect the legs including the feet rather than the back or the stomach more rarely the hand can be affected. Patients with this variant of Stiff Person Syndrome are far less likely to have diabetes mellitus or other autoimmune conditions, and tend not to have anti-GAD antibodies (see later). Rarely there are more aggressive forms of the Stiff Person Syndrome, which lead to progressive disability over a number of years. This variant is sometimes called the Jerking Stiff Person Syndrome or Progressive Encephalomyelitis with rigidity.

Investigations: The most important investigation is antibody testing. The classical Stiff Person Syndrome carries an antibody marker, which is an antibody to an enzyme found both in the pancreas and in nerve tissue. This antibody is called anti-GAD and it occurs in high concentrations in the Stiff Person Syndrome. Much lower concentrations are sometimes found in diabetes without the Stiff Person syndrome. More rarely some other antibodies may be associated with the Stiff Person conditions. One of these is called anti­amphiphysin. Where this is found there is often also a co-existing tumor. However, this combination is very rare. Electrical recordings from the affected muscles (termed EMG) can be useful in making the diagnosis. Here the characteristic finding is an inability of the affected muscles to relax. Scans of the spinal cord can be useful in excluding a structural cause such as a disc or cyst in the spinal cord. The latter may rarely masquerade as the Stiff Person Syndrome. Finally, it is sometimes necessary to examine the fluid from around the spine (CSF) by lumbar puncture. This is to look for signs of active inflammation.

Treatment: Patients usually respond to combinations of Diazepam and Baclofen, often in reasonably high dosage. These medications can be sedating. Unusually, Baclofen can cause a slight inflammation of the liver. Dependence does not seem to be a problem with Diazepam usage in the Stiff Person Syndrome. These drugs are given orally, usually three times a day. Other oral treatments may occasionally be helpful, such as Vigabatrin, Sodium Valproate, Tizanidine and Gabapentin. These too may be sedating in high dosages. Where all drug treatments fail to give sufficient relief from spasms and pain, treatments directed against the underlying allergic condition may be useful. The choices here consist of steroids (either intravenous or orally), plasma exchange (a technique in which your blood is washed of antibodies) or intravenous pooled immunoglobulins. The latter is probably the preferred treatment of this kind. It usually requires a few days in hospital and the treatment has to be repeated every few months. The infusion of immunoglobulins can be associated with headache. As immunoglobulins are a blood product there is a theoretical and remote risk of catching a viral illness. Precautions are taken to keep this risk to an absolute minimum.

Outlook: None of these treatments leads to a cure. However, they are able to control symptoms in the majority of patients. This is particularly true in the classical Stiff Person Syndrome, which has areasonably good outlook. It tends to be a little bit more difficult to control symptoms in the Stiff Limb Syndrome, and some of these patients will require help with mobility. Progressive encephalomyelitis with rigidity is a difficult condition to treat and has a poor prognosis.

Current Research

Autoimmune diseases are due to destructive immune reactions which target specific proteins (auto antigens). Immune effector cells recognising specific auto antigens probably cause type 1 diabetes through destruction of insulin secreting cells and Stiff Person Syndrome (SPS) through impairment of nerve transmission. A combination of cellular and humoral immune changes are associated with disease development in both conditions and in both diseases the enzyme Glutamic Acid Decarboxylase-65 GAD65) is a major target auto antigen.

Preliminary studies demonstrated distinct immune responses to GAD between SPS and Type 1 diabetes. Diabetes develops in about half SPS patients and half identical twins of type 1 diabetes patients. we have the world’s largest collection of each disease. We aim to determine whether immune response to GAD in SPS patients and twin pairs with type I diabetes are: 1) disease—specific; and 2) associated with protection from diabetes. Differences between diabetic and non-diabetic cases will help understand the diseases and develop treatment based on modulating GAD reactivity.

First: So far we have measured GAD and other antibodies on 10 of the referred patients. We have more samples to collect this will be done shortly. I am about to start sending out kits for the GP’s to take blood and send it to us. Our GAD assay is one of the best and we have samples sent to us from around the UK for measurement of GAD on both newly diagnosed diabetics and possible SPS patients. We are about to start measuring antibody isotypes on all the SPS patients and will ask for further sera to do this. We have a new and improved assay for this measurement. Preliminary studies suggest further differences in the isotype profile of GAD as well as other diabetic associated antibodies between SPS and type I diabetes.

Second: The BNSU (British Neurological Surveillance Unit) have sent out cards to all the neurologists in the UK in an attempt to identify the incidence of SPS in the country. The neurologists are asked to report all cases of SPS to the BNSU and they then inform us. We write to the neurologists w ho give us brief details of the patients if they do not wish to be involved or give us permission to contact the patients if they are interested.

Third: The BNSL are to Continue a further one year ascertainment. We will carry out cellular testing when funds are available. For this our nurse will visit all those who cannot travel to collect whole fresh blood.

Fourth: We have started Phase 2 studies with injections of either GAD or Heat Shock protein in patients with diabetes and LADA (Latent Autoimmune Diabetes of Adults) in an attempt to prevent them going on to insulin by altering the adverse immune reaction. This could also hopefully be of help to SPS in the future and studies of the nerve and muscle function of these cases are underway.


Stiff Person Syndrome.

This site is solely for the support of those suffering from Stiff Person Syndrome (SPS). Family and friends of sufferers are also welcome to the same support. The site may be of interest to caregivers, care professionals and researchers, together with advocates for the condition and the general public.


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The group and charity was set up by Liz Blows with the following aims:

(1) The relief of sickness and the protection and preservation of the health of persons affected by Stiff Person Syndrome, together with their families and carers.

(2) On-going education and awareness-raising within the medical profession and the general public of Stiff Person Syndrome.

(3) The promotion of research into the causes, effects, treatment and management of Stiff Person Syndrome.

"Stiff Man Syndrome" (SMS) was the name assigned to the condition when first identified in the 1950s by Moersch and Woltman in the USA. In recent years, in the modern world of PC, the condition has become more widely known as "Stiff Person Syndrome" (SPS). SPS does not differentiate between sex, colour, or creed, although UK evidence tends to suggest women are most at risk.

SPS is an auto-immune neurological condition. It is unique due to its lack of significant similarity to any other neurological diseases. Although rare, once observed it is quite unforgettable. However, many neurologists and GPs are still unaware of the condition. In most cases, the first symptoms are insidious and victims are often initially misdiagnosed with anxiety or depression.