Bulbar function in children with spinal muscular atrophy type 1 treated with nusinersen

Area of Science:

• Neurology
• Pediatrics
• Pharmacology

Background:

• Spinal muscular atrophy (SMA) type 1 is a severe neuromuscular disorder affecting bulbar function.
• Nusinersen is a disease-modifying treatment (DMT) for SMA, but its effect on bulbar function requires detailed assessment.
• Understanding bulbar function trajectories is crucial for evaluating treatment efficacy in SMA patients.

Purpose of the Study:

• To describe bulbar function trajectories in pediatric patients with SMA type 1 treated with nusinersen.
• To evaluate the performance of the Children's Eating and Drinking Ability Scale (CEDAS) and the Oral and Swallowing Ability Tool (OrSAT) in capturing these changes.

Main Methods:

• Retrospective observational cohort study of 44 patients with SMA type 1 treated with nusinersen in the UK and Italy.
• Data collected every 6 months for 2 years, assessing bulbar function using CEDAS (a revised Paediatric Functional Oral Intake Scale [p-FOIS]) and OrSAT.
• Patients were categorized based on symptom onset: Group 1b (onset >2 weeks and <3 months) and Group 1c (onset <6 months).

Main Results:

• Over 2 years, p-FOIS/CEDAS showed lack of bulbar improvement in Group 1b (40% stable, 45% declined) and stability in Group 1c (71%).
• OrSAT indicated improvement in 47% of Group 1b and 43% of Group 1c at 2 years.
• OrSAT improvements were partly attributed to age-appropriateness issues with feeding viscosity and speech acquisition items at baseline.

Conclusions:

• CEDAS (p-FOIS) and OrSAT capture complementary information on nusinersen's effect on bulbar function in SMA type 1.
• Further research is needed to clarify bulbar function trajectories in symptomatic and presymptomatic SMA cohorts receiving various DMTs.