Stiff person syndrome is classified as a neurological disorder and it is rare. This condition typically occurs along with other autoimmune disorders and typically has an autoimmune component. The exact incidence rate is unknown, but it is estimated that less than one million people are affected. Women are found to be twice as often affected than men. This condition is also referred to as Moersch-Woltmann syndrome.
Muscle-related symptoms that range in severity are experienced by most patients with this condition. These may include:
- Muscle stiffness affecting the limbs and trunk that will come and go. This will often cause pain and stiffness, a stiff-legged walk, and exaggerated upright posture
- Over time, deformed joints and a curved lower back can occur
- When a person is startled, anxious, or upset, they may experience severe muscle spasms in their legs and arms
- During muscle spasms, the patient may suddenly fall
The diagnosis is often suggested by the symptoms. But, stiff person syndrome is a rare disorder to there is a chance that it may be misdiagnosed as another disorder that is more common, such as multiple sclerosis, fibromyalgia, Parkinson’s disease, or a psychological disorder.
If anti-GAD antibodies are present, this may confirm the diagnosis. Other antibodies may confirm the diagnosis as well when there is an association with certain cancers. However, about 35 percent of patients who have this disorder will not have any associated cancers or any antibodies.
There are diagnostic tests that can also be done to help aid in making an accurate diagnosis. These may include looking for thyroiditis through a thyroid-stimulating hormone test or a hemoglobin A1C to look for diabetes. Electromyography may also be performed to test the muscles.
This disorder cannot be cured, but there are treatments that may help to relieve some of the symptoms and help to improve the patient’s quality of life. Commonly used medications include azathioprine, gabapentin, baclofen, diazepam, and tiagabine.
Steroid treatment and removing the tumor may be helpful in relieving the symptoms associated with any associated cancers.
Plasmapheresis, or plasma exchange, may he helpful in reducing some symptoms for patients, but this treatment is usually not administered unless the patient is experiencing life-threatening respiratory decline. Other patients may find IVIg, or intravenous immunoglobulin, helpful.
Symptoms related to having long-term or prolonged muscle tension may be helped by physical therapy. However, there is a chance that physical therapy may trigger muscle spasms.
Many patients also find corticosteroids helpful in reducing and relieving their symptoms. However, diabetic patients must carefully monitor their blood sugar levels often when taking corticosteroids.
Johns Hopkins Medicine. (2010). Stiff Person Syndrome. Retrieved on November 22, 2010 from Johns Hopkins Medicine: https://www.hopkinsmedicine.org/neurology_neurosurgery/conditions_main/stiff_person_syndrome.html
National Institute of Neurological Disorders and Stroke. (2010). Stiff-Person Syndrome Information Page. Retrieved on November 22, 2010 from the National Institute of Neurological Disorders and Stroke: https://www.ninds.nih.gov/disorders/stiffperson/stiffperson.htm