Stiff Person Syndrome: A Rare Presentation of a Rare Disorder

Abstract

Abstract Stiff Person Syndrome (SPS) is a rare autoimmune disease that is caused by the lack of inhibition to excitatory neurotransmitters in the central nervous system (CNS) which then leads to inappropriate and excessive motor unit firing causing stiffness, a characteristic feature of the disease. SPS has an incidence of one case in a million and occurs in the middle-aged population with a female predominance. SPS mostly occurs in the background of autoimmune disorders like type 1 diabetes, thyroid disorders, pernicious anemia, and less often, vitiligo.. The pathophysiology is not completely understood; however, there is a strong correlation between high titers of anti-glutamic acid decarboxylase antibody (anti-GAD Ab) and the disease. We present an 82 years old man who complained of stiffness and weakness, mostly on the right side, with multiple negative workups. He was then eventually diagnosed with SPS based on the characteristic history and physical examination findings and being positive for anti-GAD Ab. He was treated with a combination of baclofen, gabapentin, intravenous immunoglobulins (IVIG), and physical therapy. We review the case presentation which was unusual in terms of age and sex, and treatment options in the context of a severe presentation of this disabling disease.