Evolution of bulbar function in spinal muscular atrophy type 1 treated with nusinersen

Area of Science:

• Neurology
• Pediatrics
• Genetics

Background:

• Spinal muscular atrophy type 1 (SMA1) is a severe genetic neuromuscular disorder.
• Bulbar dysfunction significantly impacts swallowing and feeding in SMA1 patients.
• Nusinersen is a treatment approved for SMA, but its effect on bulbar function requires further investigation.

Purpose of the Study:

• To evaluate the longitudinal changes in bulbar function among SMA1 patients treated with nusinersen.
• To assess the utility of the Paediatric Functional Oral Intake Scale (p-FOIS) in monitoring bulbar function in this population.

Main Methods:

• A retrospective analysis of 24 SMA1 patients treated with nusinersen.
• Validated and adapted the p-FOIS scale to assess bulbar function.
• Collected data on SMA1 subtype, nutritional support, CHOP INTEND, and p-FOIS scores at baseline and 6, 12, and 24 months.

Main Results:

• Most patients experienced persistent bulbar impairment despite nusinersen treatment.
• The median p-FOIS score decreased from 3 at baseline to 2 at 12 and 24 months.
• Four patients (type 1c SMA) maintained oral feeding at 24 months, while median CHOP INTEND scores improved.

Conclusions:

• Bulbar dysfunction remains a significant challenge in nusinersen-treated SMA1 patients.
• The p-FOIS scale is a valuable tool for tracking bulbar function and treatment response.
• Further prospective studies are needed to understand the long-term effects of nusinersen on bulbar function.