Swallowing Assessment in Spinal Muscular Atrophy Type 1: a Real-World Study of Dysphagia in Children Receiving Disease-Modifying Therapies

Spinal muscular atrophy type 1 (SMA type 1) is a severe neuromuscular disorder characterized by early-onset muscle weakness and bulbar dysfunction. Although disease-modifying therapies (DMTs) have markedly improved motor outcomes, swallowing function in treated children with SMA type 1 remains poorly characterized. This study aimed to retrospectively describe the common features of dysphagia in this population, explore associations with motor function and clinical features, and conduct a preliminary comparison of swallowing abilities among children treated with different DMTs. We included 53 patients, assessed between September 2021 and December 2025, using the Mealtime Assessment Scale (MAS), the Oral and Swallowing Abilities Tool (OrSAT), the Food Intake LEVEL Scale (FILS), and the paediatric Functional Oral Intake Scale (p-FOIS). Motor function was assessed using the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) and the Hammersmith Infant Neurological Examination motor milestone module (HINE-2). A distinctive dysphagia profile emerged. All swallowing scales showed strong correlations (r = 0.733-0.964, p < 0.001). Safety and efficiency were positively correlated with motor scores (p < 0.05); swallowing function was higher in sitters than in non-sitters; and differences were observed among DMTs. Based on our findings, routine swallowing assessment should be implemented in all patients with SMA type 1.