Natural history in hereditary spastic paraplegias: real-world data from an Austrian cohort

INTRODUCTION: Hereditary spastic paraplegias (HSP) are rare inherited neurodegenerative disorders characterized by progressive lower limb spasticity and weakness. This study aimed to characterize an Austrian HSP cohort and prospectively assess disease progression using the Spastic Paraplegia Rating Scale (SPRS), addressing the knowledge gap regarding its longitudinal capabilities in a real-world setting. METHODS: Data from 126 patients were collected at the Center for Rare Movement Disorders Innsbruck. Baseline clinical data were available for 103 individuals. Follow-up extended up to 5 years (mean 2.3 ± 1.9). Disease severity was assessed with the SPRS, and longitudinal progression analyzed using generalized linear mixed models. RESULTS: The cohort (64.3% male, mean age 47.1 years) included 54.8% patients with complicated HSP. Genetic confirmation was achieved in 54.0%, with SPAST being the most frequent genotype (36.8%). Mean baseline SPRS was 18.2 points. SPRS scores increased significantly with disease duration, with an overall annual progression of 0.9 points (p < 0.001). Progression was faster in complicated versus pure HSP (1.3 vs. 0.6 points/year; p < 0.001). Most patients received symptomatic medication (69.8%) and neurorehabilitation (84.1%). CONCLUSION: This study provides comprehensive real-world data on HSP from an Austrian cohort, including clinical, genetic, management, and imaging findings. We present the first prospective assessment of SPRS progression in a natural history cohort, revealing significant longitudinal change. Taken together, our findings may contribute to the design of future therapeutic trials in HSP.