Effect of surgical obstructive sleep apnea treatment on periodic limb movements of sleep in pediatric patients

INTRODUCTION: The relationship between obstructive sleep apnea (OSA) and periodic limb movements of sleep (PLMS) is not completely understood, especially among children. This study evaluates the effect of surgical OSA treatment on PLMS in pediatric patients. METHODS: This retrospective record review included children aged 1-18 years who underwent polysomnography (PSG) prior to and after airway surgery between 1/1/2010 and 7/31/2022. Only patients with OSA (obstructive apnea-hypopnea index (OAHI) ≥ 1.5/hour) and any pre-treatment or post-treatment PSG with PLMS elevation (PLM Index (PLMI) ≥ 5/hour) were included. PLMI and OAHI changes after OSA treatment were evaluated by mixed effect linear models. RESULTS: 198 children met inclusion criteria. The average age was 5.3 ± 3.8 years at pre-treatment PSG. Adenotonsillectomy was the most common surgery (n = 136). OAHI decreased from 12.3 ± 15.3 to 5.3 ± 8.1/hour (p < 0.01) and PLMI increased from 5.5 ± 8.5 to 7.0 ± 8.7/hour after treatment, with an average PLMI increase of 1.5/hour (SE = 0.7, p = 0.04). Children with decreased OAHI after surgery (n = 152) showed an average PLMI increase of 2.3/hour (SE = 0.8, p = 0.004), while children with increased OAHI (n = 44) showed no significant PLMI change. 74 children (37.4%) had post-surgical PLMS elevation not observed on pre-surgery PSG, while 36 children (18.2%) had PLMS elevation on pre- and post-surgery PSG. CONCLUSIONS: Effective OSA treatment led to increased PLMI among most children, highlighting possible PLMS unmasking in some children with OSA. Furthermore, over one third developed PLMS elevation after OSA treatment, suggesting a sub-group of children with OSA and a possible sleep-related movement disorder phenotype that may not become apparent until OSA treatment.