Impact of Early Pharmacological Interventions on Scoliosis Progression in Type II SMA

A recent study has shed new light on the potential impact of early pharmacological interventions on scoliosis progression in individuals with Type II spinal muscular atrophy (SMA). Scoliosis, affecting up to 90% of Type II SMA cases, poses a significant challenge, and while treatments have shown improvements in motor function, their effect on scoliosis remains uncertain. This study was published in the Journal Of Neurology Neurosurgery and Psychiatry by Giorgia Coratti and colleagues.

Study Objectives and Methods

The study aimed to investigate differences in scoliosis progression between treated and untreated Type II SMA patients. Researchers analyzed the effect of treatment on Cobb’s angle annual changes and the likelihood of reaching a critical 50° Cobb angle in patients with a minimum 1.5-year follow-up. The study utilized a sliding cut-off approach to identify the optimal treatment subpopulation based on age, initial Cobb angle, and Hammersmith Functional Motor Scale Expanded at the initial visit. The Mann-Whitney U-test assessed statistical significance.

Key Findings

Comparing a cohort of 46 untreated individuals with 39 treated patients, the study initially found no significant differences in baseline characteristics. However, when analyzing the impact of pharmacological treatment on scoliosis progression, intriguing patterns emerged:

• The mean Cobb angle variation did not significantly differ between the treated and untreated groups initially.
• Upon exploring optimal cut-off values for a better outcome, the treated group, especially those with a Cobb angle <26° or an age <4.5 years, demonstrated a significantly lower mean Cobb angle variation.
• The treated group showed a lower mean Cobb variation compared to the untreated group (5.61 (SD 4.72) degrees/year vs 10.05 (SD 6.38) degrees/year; p=0.01).
• Cox-regression analysis indicated a protective effect of treatment in preventing patients from reaching a 50° Cobb angle, particularly pronounced in patients younger than 4.5 years old (p=0.016).

Conclusion

The study's results underscore a potential correlation between early pharmacological treatment initiation and slowed scoliosis progression in Type II SMA patients. These findings emphasize the importance of early intervention, particularly in individuals under 4.5 years old or those with a lower initial Cobb angle, suggesting a more favorable response to treatment. However, researchers caution that larger-scale studies are imperative to delve deeper into the efficacy of individual pharmacological treatments on scoliosis progression in this patient population.

Reference

Coratti, G., Lenkowicz, J., Pera, M. C., D’Amico, A., Bruno, C., Gullì, C., Brolatti, N., Pedemonte, M., Antonaci, L., Ricci, M., Capasso, A., Cicala, G., Cutrona, C., de Sanctis, R., Carnicella, S., Forcina, N., Cateruccia, M., Damasio, M. B., Labianca, L., … Mercuri, E. Early treatment of type II SMA slows rate of progression of scoliosis. Journal of Neurology, Neurosurgery, and Psychiatry, 2023, jnnp-2023-332084. https://doi.org/10.1136/jnnp-2023-332084