O perfil respiratório de crianças com atrofia muscular espinhal tipo I em uso de terapias modificadoras da doença

Abstract

Introduction: Spinal Muscular Atrophy (SMA) is a disease characterized by muscle atrophy secondary to the degeneration of motor neurons, leading to progressive muscle weakness with significant respiratory involvement. Type 1 is the most severe and prevalent form. Over the past decade, disease-modifying therapies (DMTs) have shown promising results in increasing survival and improving motor function. However, few studies have focused on the effects of these therapies on respiratory function. Objective: To describe the respiratory function characteristics of children with SMA type 1 undergoing DMT (nusinersen, risdiplam, or onasemnogene abeparvovec). Methods: This is a descriptive, ambidirectional, longitudinal study conducted at the Instituto de Puericultura e Pediatria Martagão Gesteira (IPPMG) of the Federal University of Rio de Janeiro (UFRJ), between September 2022 and August 2025. participants were stratified according to the type of respiratory support at baseline, non-invasive ventilation (NIV) or invasive mechanical ventilation (IMV) and evaluated at three time points over 24 months of treatment. Variables included daily hours of ventilatory support, frequency of respiratory infections, home respiratory care, and motor function using the CHOP INTEND scale. Descriptive statistics were used for sample and variable analysis. An exploratory analysis was conducted to assess changes after DMT initiation and to explore differences between subgroups. Results: Thirteen participants were included: 8 (62%) female, 11 (85%) with SMA subtype 1B, 8 (62%) in the NIV group and 5 (38%) in the IMV group. No deaths or changes in the type of ventilatory support were observed during the study period. Participants in the NIV group had a lower mean age at DMT initiation (20 ± 36 months) and fewer daily hours of ventilatory support across all three time points. However, no differences were observed between groups in the occurrence of respiratory infections or hospitalizations. Conclusions: The findings demonstrate respiratory stabilization at different stages of disease progression and a reduction in daily ventilatory support time in five participants from the NIV group. These results highlight the need for broader investigations into the impact of early DMT initiation on ventilatory dependence and the factors influencing the incidence of respiratory infections. This is one of the few Brazilian studies to address this topic.