Clinical and Immunologic Findings in Stiff-Person Spectrum Disorder

Stiff-person syndrome (SPS) is characterized by fluctuating muscle rigidity and painful spasms triggered by diverse stimuli. Segmental forms, such as stiff-limb syndrome (SLS) or the more severe disease called progressive encephalomyelitis with rigidity and myoclonus (PERM) or other atypical and overlapping syndromes, are considered part of a spectrum of SPS (stiff-person spectrum disorder; SPSD). For all these disorders, evidence suggests underlying immune mechanisms that target proteins expressed in the inhibitory synapses. SPS also is frequently comorbid with diabetes and other autoimmune diseases (vitiligo, celiac sprue, rheumatologic diseases, and thyrogastric disorders).

Researchers retrospectively examined 121 cases with clinical feat…