Autoimmune Stiff-Person Syndromes

Stiff-person spectrum disorder (SPSD) is a rare autoimmune condition encompassing various syndromes characterized by central nervous system hyperexcitability. This disorder manifests as progressive stiffness, spasms, and an exaggerated startle response to different stimuli, typically unfolding in a subacute manner. Several autoantibodies have been associated with SPSD, but the most common is the presence of high titers of anti-glutamic acid decarboxylase (anti-GAD). Accurate diagnosis of these syndromes demands a high degree of suspicion, necessitating a comprehensive therapeutic approach involving both antispasmodic medications and immunomodulatory treatments.