[Successful treatment with rituximab in a refractory Stiff-person syndrome]

Stiff person syndrome is a rare autoimmune disorder characterized by axial and limb progressive stiffness with surimposed spasms and production of autoantibodies to glutamic acid decarboxylase (GAD). We report a case of a 50-year-old woman who developed a stiff person syndrome resistant to conventional immunosuppressive treatments. Eight months after treatment, indexes of stiffness and spasm frequency improved, while however, the blood and CSF rates of anti-GAD increased. This observation illustrates the complexity of stiff person syndrome immunopathogenesis as well as the relevance of rituximab in this indication.