BACKGROUND: Spinal muscular atrophy (SMA) is a rare neurodegenerative disease that significantly affects multiple systems in children. Nusinersen, the first approved treatment for SMA, enhances SMN protein production by targeting the RNA splicing site of the SMN2 gene, thus improving motor function. However, the high cost of nusinersen treatment raises concerns about its economic feasibility. METHODS: This study retrospectively analyzed clinical data of 42 pediatric SMA patients treated with nusinersen from January 2022 to October 2024 at our hospital. We assessed the efficacy, safety, and economic impact of nusinersen in different SMA types. Motor function was evaluated using the CHOP-INTEND, HINE-2, HFMSE, and RULM scales. Safety was assessed based on adverse reactions and events, and economic evaluation considered total treatment costs and average cost per injection. RESULTS: Nusinersen significantly improved motor function in SMA patients, especially in type I patients, who showed notable increases in CHOP-INTEND and HINE-2 scores. The RULM score had the highest increase among type II patients, while improvements were relatively lower in type III patients. Regarding safety, the incidence of adverse events was 40.48%, with fever being the most common adverse reaction, occurring in 36.36% of cases. Economic analysis indicated that the total treatment cost was highest for type III patients, though the cost differences among types were not statistically significant (P >
0.05). CONCLUSION: Nusinersen demonstrated significant clinical efficacy and favorable safety in pediatric SMA patients, with improved economic feasibility after insurance coverage. Our findings support early SMA screening and presymptomatic nusinersen administration to maximize therapeutic benefits. Further multicenter, large-sample, long-term follow-up studies are warranted to validate and expand upon these findings.