Key insights:
1. Elevated periodic limb movements are relatively common in pediatric OSA – and are associated with more severe disease. Nearly 10% of children with OSA had an elevated periodic limb movement index (PLMI), with higher rates seen in children with moderate to severe OSA. This suggests clinicians should recognize PLMI as a frequent comorbidity when evaluating pediatric sleep-disordered breathing.
2. Adenotonsillectomy resolves elevated PLMI in most children with OSA. Among children who had both pre- and postoperative sleep studies, 85% experienced resolution of elevated PLMI, with mean PLMI decreasing from 11.9 to 2.9 movements per hour. These findings support that limb movements often improve following treatment of the underlying airway obstruction.
3. Persistent limb movements after surgery warrant further evaluation – not automatic treatment.Residual PLMI may indicate persistent OSA or another sleep disorder, so postoperative management should be guided by ongoing symptoms. Repeat polysomnography, ferritin testing, or referral to pediatric sleep medicine should be considered when clinically indicated, rather than routinely treating PLMI as a separate condition.
Intro: Periodic limb movements and OSA
Some children with obstructive sleep apnea (OSA) also have periodic limb movements during sleep. Evidence on whether these movements improve after adenotonsillectomy has been limited and conflicting.
Seeking greater clarity, researchers at Children’s Health℠ retrospectively reviewed the records of 1,159 children with OSA who underwent adenotonsillectomy. The objective was to see how often these movements occurred and whether surgery reduced them. The resulting study, published in The Laryngoscope, provides useful guidance toward more consistent care.
In the Q&A below, three Children’s Health experts discuss the study findings and what they mean for pediatric care.
Ron Mitchell, M.D., Division Director of Pediatric Otolaryngology at Children's Health and Professor at UT Southwestern.
Seckin Ulualp, M.D., Pediatric Otolaryngologist at Children's Health and Professor at UT Southwestern.
S. Kamal Naqvi, M.D., Pediatric Pulmonologist/Sleep Medicine Specialist at Children's Health and Professor at UT Southwestern.
Why do periodic limb movements matter in children with OSA?
Dr. Ulualp: Periodic limb movements during sleep are involuntary movements of the limbs, typically the legs, that occur at regular intervals during sleep. We measure these movements with the periodic limb movement index (PLMI); a PLMI above five movements per hour is considered elevated in children. Families of children with OSA often notice these movements but may assume they're a normal part of sleep.
Dr. Naqvi: Frequent movements can disrupt sleep, and the effects aren’t confined to the night. Poor-quality sleep can show up during the day as trouble with attention, behavior or school performance.
How common was elevated PLMI and which children were more likely to have it?
Dr. Ulualp: Elevated PLMI occurred in nearly 1 in 10 children in our study – that’s 114 of 1,159. Children with moderate or severe OSA were more likely to have it than children with mild OSA. Elevated PLMI was more common in preschoolers, grade-school children and teenagers than in toddlers, a pattern we're still working to understand. We found no significant differences based on sex, race, ethnicity or weight category.
What happened after adenotonsillectomy?
Dr. Mitchell: Measuring whether surgery affects PLMI requires a sleep study both before and after the operation. Of the 114 children with elevated PLMI, 54 had both studies. In that subgroup, elevated PLMI resolved in 46 children, (85%), and mean PLMI fell from 11.9 to 2.9 movements per hour. The other 60 didn't have a post-operative study because it isn't routine unless symptoms persist.
Dr. Ulualp: We also found that children with residual OSA had a higher postoperative PLMI than those whose OSA resolved. This finding suggests that OSA may play a role in PLMI, although the study wasn’t designed to establish whether the two are causally linked or simply occur together.
How should these findings shape treatment decisions?
Dr. Mitchell: Adenotonsillectomy and observation may both be reasonable options for children with mild sleep-disordered breathing. Elevated PLMI may tip the scale when a child already has OSA and enlarged tonsils or adenoids, but it’s the airway findings – not the limb movements – that indicate surgery. And some reassuring news for families: for most children, limb movements resolve after surgery.
Dr. Naqvi: The real question after surgery is whether the limb movements are a distinct problem. The next step is to reassess the child’s sleep and daytime functioning, rather than assuming at the outset that the movements require separate treatment.
What should providers do if sleep concerns or elevated PLMI persist?
Dr. Naqvi: Ask whether the child’s sleep and daytime concerns – such as sleepiness, attention, behavior or school difficulties – have improved. Persistent concerns may reflect residual OSA or another sleep disorder.
Depending on a child’s symptoms, next steps may include a repeat sleep study, ferritin testing or referral to pediatric sleep medicine. Ferritin testing can help determine whether iron supplementation may benefit a symptomatic child who has low iron stores. These steps aren’t routine for every child after surgery.
What’s on the horizon for your research?
Dr. Ulualp: This study moves us closer to the evidence needed to guide care for children with OSA and elevated PLMI. We’re continuing to study why elevated PLMI varies by age and persists in some children after adenotonsillectomy. We also hope that other pediatric centers will replicate our findings in broader patient populations so we can develop more consistent evaluation and treatment pathways.
What makes Children’s Health stand out in pediatric sleep care?
Children’s Health has one of the largest groups of pediatric ENT physicians in North Texas, including clinicians who lead research and care for children with airway conditions that affect sleep. Pediatric otolaryngologists work closely with pulmonologists and sleep medicine specialists, coordinating care based on whether a child needs airway treatment, further sleep evaluation or both. This approach connects referring providers with surgical and nonsurgical expertise as their patients’ needs evolve.
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