Stiff-Person syndrome: a rare neurological disorder with features of an autoimmune disease, characterized by fluctuating muscle rigidity in the trunk and limbs and an enhanced sensitivity to stimuli such as noise, touch, and emotional distress. Muscle spasms may also be present as a result of the sensitivity to various stimuli, leading to abnormal postures and stiffening. Stiff-Person syndrome (SPS) is more common in women than in men and is often associated with other autoimmune diseases including, pernicious anemia, diabetes, vitiligo, and thyroiditis. The exact cause of Stiff-Person syndrome is unknown, but it appears to result from an autoimmune reaction.
Medically reviewed by Martin Zipser, MD; Board Certified: Surgery