Stiff Person Spectrum Disorders-An Update and Outlook on Clinical, Pathophysiological and Treatment Perspectives

Abstract

Stiff person spectrum disorders (SPSD) are paradigm autoimmune movement disorders characterized by stiffness, spasms and hyperekplexia. Though rare, SPSD represent a not-to-miss diagnosis because of the associated disease burden and treatment implications. After decades as an enigmatic orphan disease, major advances in our understanding of the evolving spectrum of diseases have been made along with the identification of multiple associated autoantibodies. However, the most important recent developments relate to the recognition of a wider affection, beyond the classic core motor symptoms, and to further insights into immunomodulatory and symptomatic therapies. In this review, we summarize the recent literature on the clinical and paraclinical spectrum, current pathophysiological understanding, as well as current and possibly future therapeutic strategies.

Keywords: autoimmune movement disorders; autoimmunity; glutamic acid decarboxylase; stiff person spectrum disorders; stiff person syndrome.

Figure 1

Clinical phenotypes of SPSD. Created with BioRender.com (accessed on 31 July 2023).

Figure 2

Features in SPSD beyond the classic motor symptoms. Created with BioRender.com (accessed on 31 July 2023).