Stiff-Person Syndrome Information Page: National Institute of Neurological Disorders and Stroke (NINDS)

What is Stiff Person Syndrome...

Stiff-Person Syndrome Information Page: National Institute of Neurological Disorders and Stroke (NINDS): "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. People with SPS can be too disabled to walk or move. 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."

What in the World is Stiff Person Syndrome?

In the United States, a rare (or orphan) disease is defined by the National Organization of Rare Diseases (NORD) as a disorder affecting less than 200,000 Americans (approximately 1 in 1,500 individuals). One such rare disease is believed to affect only 1 in 1,000,000 individuals, worldwide.

This orphan is known as Stiff Person Syndrome (SPS)

Although considered an Autoimmune Disease, it is often classified as Neurological, characterized by rigidity and/or spasticity of the skeletal muscles, tremors, anxiety, and a hyper-excitability of the muscles. Known as the startle reflex, emotional stress, a sudden, unexpected noise, or even a gentle touch, are known to cause prolonged, often severe, spasms, and is considered unique to SPS.

The result of constant spasms is unrelenting pain and commonly, eventual disability. In later stages of SPS, virtually no muscle is spared from spasm, and these may be violent enough to result in torn muscle tissue, and broken bones. Frequent falls are common among those with SPS, as they lack normal balance. These falls can be serious due to an inability to react, and muscles may become rigid during the crisis.

Average time to diagnose the disease is 7 years, and misdiagnoses during this period include:

Anxiety (Conversion) Disorder, Phobia, Multiple Sclerosis, Dystonia, PTSD, Fybromialgia, Parkinson's Disease, and Psychosomatic Illness

It is discouraging that a lack of awareness of Stiff Person Syndrome is responsible for this prolonged delay in diagnosis.

The cause of SPS is unknown, and there is no cure. It has been theorized that SPS may be caused by a virus in the brain and CSF which introduces elevated levels of the auto-antibody, glutamic acid decarboxylase (GAD65), preventing adequate production of gamma-Aminobutyric acid (GABA) in the brain. This is a crucial neurotransmitter, and one of the body's natural anti-anxiety chemicals.

Diagnosis is most often made from a blood test which reveals even the slightest elevated level of GAD65, although an undetermined percentage will eventually be diagnosed without any elevation of GAD65.

There are treatments which can relieve the patient of some pain, spasticity, and anxiety. These treatments may slow the progression of the disease but it is rarely halted, and disability can be delayed, although once a patient has become wheelchair-bound it is doubtful the disability will be reversed.

Common treatments for Stiff Person Syndrome symptoms include:
• High doses of Valium (Diazepam) and/or Ativan (Lorazepam) for anxiety and muscle spasms
• Baclofen, a muscle relaxant (often dispensed from an implanted pump, called Intrathecal Baclofen)
• Neurontin (Gabapentin), a seizure medicine, and
• Intravenous Immunoglobulin (IVIg), made from thousands of healthy blood donors for a single dose, to help

negate some of the effects of GAD antibodies, and contribute to the production of GABA.

These treatments will be required for the life of the patient, in varying doses and frequency.

Other Autoimmune Diseases, including Diabetes Mellitus, Thyroiditis, Lupus, and Pernicious Anemia, are commonly found in those with Stiff Person Syndrome.
Depression is common and difficult to treat due to Neurological side effects from most Antidepressants, exacerbating SPS symptoms.