Effect of Nusinersen on Respiratory and Bulbar Function in Children with Spinal Muscular Atrophy: Correspondence

Dear Editor,

We would like to comment on “Effect of Nusinersen on Respiratory and Bulbar Function in Children with Spinal Muscular Atrophy: Real-World Experience from a Single Center.[1]” Studies examining the impact of nusinersen on capillary function and respiration in young patients with spinal muscular atrophy (SMA) are significant breakthroughs in therapy choices, but they are not without limits. One significant limitation is the small sample size of only 28 juvenile patients representing various SMA subtypes. Small sample sizes increase the danger of sampling bias and limit the generalizability of the results. The disproportionate number of type 1 SMA patients, who make up the vast majority, raises questions about the data's applicability throughout the full SMA spectrum. Future research should attempt to recruit larger and more balanced samples, including a more equitable mix of SMA types, to enhance the data-driven results. Furthermore, establishing causal correlations is difficult due to the study's observational design. Although the study demonstrated that starting nusinersen earlier resulted in better outcomes, it did not account for confounding variables that could have influenced clinical outcomes, such as differences in standard care practices or patients' underlying medical conditions. These uncontrollable variables could bias the results. This makes it difficult to say whether the reported improvements are due to nusinersen or other environmental causes. Future research could use a randomized controlled trial comparing nusinersen to a placebo group to improve the validity of the study outcomes.

Furthermore, the study noted that the vascular head's function, particularly swallowing and eating, remained stable during the monitoring time. Given the importance of vascular head function in SMA patients' quality of life, it highlights the necessity for additional research into this component of patient care. Future research should focus on identifying specific interventions or care strategies that can support vascular function in conjunction with nusinersen treatment, not only assessing patient-reported quality of life outcomes, but also investigating the role of speech and functional therapy in conjunction with pharmacological interventions.

Finally, while the absence of deaths during the research period is reassuring, it does not provide a whole picture of nusinersen's long-term safety and effectiveness. A minimum 24-month follow-up is insufficient to determine the durability of outcomes, including potential adverse effects and long-term implications on growth and development in the pediatric population. Future research should include a longer follow-up period to better understand the long-term consequences of nusinersen treatment. It would be beneficial to investigate the drug's impact on physical growth, brain function, and overall health in children with SMA. Such long-term research may provide insights into the best timing to start treatment, guiding clinical decision-making, and improving patient outcomes.

Artificial Intelligence Declaration

The author use language editing computational tool in preparation of the article.

Authors' Contribution

H.P.: 50% ideas, writing, analyzing, approval; V.W. 50% ideas, supervision, approval.

Publication History

Received: 10 September 2024

Accepted: 03 October 2024

Article published online:
22 October 2024

• Reference

• 1 Gaboli M, López Lobato M, Valverde Fernández J. et al. Effect of nusinersen on respiratory and bulbar function in children with spinal muscular atrophy: real-world experience from a single center. Neuropediatrics 2024;