According to the National Institute of Neurological Disorders and Stroke (NINDS) at the National Institutes of Health (NIH), Stiff Person Syndrome (SPS) is a “rare neurological disorder with features of autoimmune disease” and is characterized by fluctuating muscle rigidity in the trunk and limbs. SPS is also characterized by a heightened sensitivity to noise, touch, emotional distress, and other stimuli, which can set off muscle spasms. People with this syndrome may be afraid to leave their homes due to street noises possibly triggering spasms and falls. It may be misdiagnosed as Parkinson’s disease, multiple sclerosis, fibromyalgia, psychosomatic illness, or anxiety and phobia. For a definitive diagnosis, your doctor may order a blood test that measures the level of glutamic acid decarboxylase (GAD) in your blood. People with SPS have elevated levels of GAD. Scientists do not yet understand what causes SPS. Research, however, indicates that it may be the result of an autoimmune response gone awry in the brain and spinal cord.

People with SPS can have frequent falls and may experience injuries that can be severe because muscle spasms may make it difficult to stop or lessen a fall. A recent study funded by NINDS demonstrated the effectiveness of intravenous immunoglobulin (IVIg) treatment in reducing stiffness and lowering sensitivity to stimuli and stress in people with SPS. Treatment with IVIg, muscle relaxers, anti-convulsants, pain relievers, and anti-anxiety medications may improve the symptoms of SPS but will not cure the disorder. However, with appropriate treatment, the symptoms of SPS may be well controlled.