What is Stiff Person Syndrome?
Stiff person syndrome is a rare autoimmune movement disorder that affects the brain and spinal cord. People suffering from this condition experience stiffening of the trunk muscles followed by stiffness and rigidity in the legs and other body parts.
Otherwise known as Moersch-Woltman syndrome, stiff person syndrome can cause severe muscle spasms. The spasms can occur randomly or may be triggered by noise, emotional distress, light, or touch. Over time, this syndrome can alter posture and in severe cases it cab decrease the ability to walk and move. People who suffer from this condition need ongoing treatment for a prolonged period to manage the symptoms and maintain quality of life.
Stiff person syndrome is believed to be a part of a wide range of similar diseases that involve a particular area of the body. This condition then progresses to involve the whole body.
Who is at high risk of getting stiff person syndrome?
Since the stiff-person syndrome is sporadic, it affects only about one out of every one million of the population. Women are more affected than men. The symptoms of this disease can develop at any age, most commonly in the age group 30 to 60 years.
This condition is likely to develop in people who suffer from the following conditions:-
• Autoimmune conditions like pernicious anaemia, vitiligo, thyroiditis, and diabetes type 1.
• Certain types of cancer like tumours of kidney, thyroid, colon, and Hodgkin’s lymphoma.
What causes Stiff person syndrome?
The exact cause behind this syndrome is not known. Although it is believed that stiff-person syndrome is an autoimmune disorder, the same mechanism behind this condition is yet to be discovered. Several researchers have concluded that in this syndrome, the body produces antibodies against an enzyme called glutamic acid decarboxylase (GAD).
This enzyme plays a vital role in producing GABA. As a result, the concentration of GABA decreases in the body. Antibodies to another protein called Amphiphysin are also found in some patients. This protein is predominantly present in nerve terminals and is involved in nerve transmission. The exact role of GAD in developing stiff-person syndrome is not understood. Some of the affected people do not have detectable levels of antibodies against GAD.
What are the symptoms of Stiff person syndrome?
Symptoms of this syndrome may take several months to develop. Some people remain stable while the condition of others worsens over time. In most patients, the trunk and abdomen muscles are the first affected. The stiffness may come and go in the early part of the disease, but eventually, the stiffness remains constant. As the disease progresses, some people develop hunched posture. In addition, painful muscle spasms may occur. These spasms may last for a few seconds, minutes, or a few hours. Sometimes, cramps can be severe enough to dislocate a limb, break a bone, or cause falls. Sleep usually decreases due to the frequency of these spasms.
Diagnosis of Stiff person syndrome
A blood test is done to detect antibodies against GAD or Amphiphysin levels. Unfortunately, 60-80%of people with the stiff syndrome have antibodies against GAD.
A machine is used to measure the electric activity in the muscles to look for continuous motor activity.
During a lumbar puncture, a doctor uses a needle to draw fluid from the spinal canal to check for the presence of antibodies to GAD.
How is stiff-person syndrome managed or treated?
The treatment of this syndrome depends on the symptoms. Therefore, the ultimate goal behind the treatment is to manage symptoms and improve the ability to move.
Therapies include medicines like benzodiazepines or baclofen to reduce muscle stiffness and spasms. Anti-epileptic medication may reduce pain. The use of anti-inflammatory drugs may help to decrease the cases of distress.
Other treatment options include immunoglobulins, plasmapheresis, rituximab, and stem cell transplant. In addition, non-medical therapy like massage, water therapy, heat therapy, and acupuncture can also be used.
What are the complications of stiff person syndrome?
Some of the common complications of this syndrome are mental health problems like anxiety and depression, dislocated or broken bones, excessive falls, and excessive sweating.
Stiff person syndrome can not be treated but can only be managed based on symptoms one may experience. It is an uncommon condition. Unfortunately, there are no ways by which it can be treated.