Systematic Review of Immune and Symptomatic Treatments for Stiff‐Person Syndrome

Background and Purpose This systematic review evaluated the effectiveness and safety of immune and symptomatic treatments in patients with stiff‐person syndrome (SPS). Methods A systematic search of PubMed, Embase, and the Cochrane Library was conducted up to September 30, 2024 in accordance with the PRISMA guidelines. All studies that involve SPS patients treated with symptomatic pharmacotherapy or immunotherapy and where the outcome is reported were included in the initial screening. Case reports were excluded. Two independent reviewers carried out study selection, bias assessment with the Murad et al. tool for case series, ROBINS‐I for observational studies or RoB‐2 for randomised trials, and data extraction into a predefined template. All available efficacy and safety data were recorded. A narrative synthesis was conducted to address the heterogeneity of the studies. Results Thirty‐six studies were included. Most of the included studies consisted of small‐scale studies, with 21 case series, 10 cohort studies and only five randomised controlled trials. Outcome assessments varied across the reviewed studies. Most studies assessed measures with subjective self‐report and/or through clinical observations. Spasms and stiffness were assessed in around 60% of studies. Walking ability and pain were evaluated in less than half of studies. Only 10 (28%) studies assessed functional improvement using a valid and reliable tool. The present review highlights the paucity of data and the heterogeneity in SPS treatment responses and underscores the need for individualised therapeutic strategies. Conclusions Standardised assessment methods in clinical practice are necessary to benefit understanding and approval of future therapy strategies.