Obstructive Sleep Disordered Breathing

The tongue plays a key role in maintaining upper airway patency during sleep, mainly through the genioglossus, the principal pharyngeal dilator muscle. Its dysfunction may be linked to the development of obstructive sleep-disordered breathing (oSDB), a condition affecting more than one in ten children and associated with cardiovascular and cognitive consequences. Although adenotonsillectomy remains the treatment of choice, it fails in a substantial proportion of cases because of persistent obstruction at other sites, the tongue base being involved in one third of these cases. Therefore, a better characterization of the tongue in children with oSDB is needed, since the extent to which its structure and function contribute to upper airway obstruction in this population remains largely unknown. Our team has established the reproducibility of tongue function measurements in healthy children and is currently building a reference database. What is still lacking is an assessment of tongue structure and function in children with oSDB. Such data would allow comparison with healthy children, thereby improving the understanding of oSDB pathophysiology and informing clinical management. Primary objective: To describe tongue structure and function in children with oSDB. Secondary objective: To compare tongue structure and function between children with oSDB and healthy children, using data from a previous study conducted in healthy children (TMAC study, UCLouvain).

Obstructive sleep-disordered breathing, including obstructive sleep apnea (OSA), represents a significant yet underdiagnosed condition in the pediatric population, particularly among adolescents with obesity. The tongue is a central anatomical contributor to upper airway collapsibility; however, its biomechanical properties have been investigated almost exclusively in adult populations, leaving a critical gap in knowledge regarding younger individuals. This study aims to assess tongue biomechanical and echographic characteristics using quantitative ultrasound modalities - shear-wave elastography (SWE), acoustic attenuation, and echo intensity - in adolescents aged 12 to 18 years with obesity and obstructive sleep disorders. The study adopts a mixed design combining (1) an observational cross-sectional comparison between participants with obesity and OSDB and age- and sex-matched healthy controls at baseline, and (2) a prospective longitudinal cohort component evaluating changes in tongue ultrasound characteristics over the course of a 30-week multidisciplinary inpatient weight-loss program delivered as standard care at the Zeepreventorium (De Haan, Belgium). An additionnal methodological objective consists in determining intra-rater and inter-rater reliability of the ultrasound acquisition protocol providing a reproducible framework for future studies.

This study investigates the hypothesis that, in children, tongue motor functions can predict both the anatomical site and the degree of upper airway obstruction contributing to obstructive sleep-disordered breathing.