Stiff person syndrome (SPS) is a neurological disorder. It appears to be similar to an autoimmune disease. This rare condition appears to affect more women than men, but does not heavily affect any particular ethnic or racial group. Sufferers usually experience progressively worsening symptoms.
A patient afflicted with stiff person syndrome typically begins to experience symptoms in his mid-forties. Muscle stiffness and rigid limbs and torso are common among these patients. Patients may affect abnormal postures, such as being markedly hunched over.
Certain stimuli may trigger an episode of symptoms. Patients may be especially sensitive to touch, noise, and emotional stress. Any of these triggers may result in muscle spasms, which can lead to falls.
The exact cause of stiff person syndrome is not known. SPS may be due to the brain or spinal cord misinterpreting an autoimmune response. It may also have a connection with some autoimmune diseases. For example, patients with SPS may also suffer from diabetes, vitiligo, and thyroid disease. These patients may also be more prone to developing epilepsy.
Patients may initially receive an incorrect diagnosis. Stiff person syndrome may be misdiagnosed as multiple sclerosis, Parkinson’s disease, or fibromyalgia. Sometimes, it may also be attributed to phobias, anxiety, or a psychosomatic illness.