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Periodic limb movements in children: prevalence in a referred population
1Division of Respiratory Medicine, Department of Pediatrics, University of Calgary, Calgary, Alberta, Canada. val.kirk@calgaryhealthregion.ca
Insights
Periodic limb movements of sleep (PLMS) are uncommon in children, affecting only 1.2% of those evaluated for sleep disorders. Isolated PLMS, without other conditions like obstructive sleep apnea, is rare in pediatric sleep evaluations.
Area of Science:
- Pediatric Sleep Medicine
- Neurology
- Respiratory Medicine
Background:
- Periodic limb movements of sleep (PLMS) are characterized by repetitive limb movements during sleep.
- PLMS can be associated with sleep disruption and daytime symptoms.
- The prevalence of PLMS in children referred for sleep evaluations is not well-established.
Purpose of the Study:
- To determine the prevalence of periodic limb movements of sleep (PLMS) in children referred for evaluation of sleep disorders.
- To assess the co-occurrence of PLMS with other sleep conditions, such as obstructive sleep apnea (OSA).
- To investigate the prevalence of isolated PLMS in this pediatric population.
Main Methods:
- Retrospective analysis of overnight polysomnograms (PSG) from a tertiary-level pediatric care facility.
- Inclusion criteria: all children undergoing PSG between October 1999 and March 2003.
- Data extracted included PLM index, PLM with arousal index, apnea-hypopnea index (AHI), and patient demographics.
Main Results:
- A total of 591 PSG studies were reviewed.
- 5.6% of children had evidence of PLMS (> 5 per hour).
- 1.2% of children had isolated PLMS without other comorbidities; 60% of those with PLMS also had obstructive sleep apnea.
Conclusions:
- Periodic limb movements of sleep (PLMS) are uncommon in children referred for sleep disorder evaluations.
- The prevalence of isolated PLMS in this pediatric population is low (1.2%).
- PLMS frequently co-occurs with other sleep disorders, particularly obstructive sleep apnea.
Study Objectives:
To determine the prevalence of periodic limb movements of sleep (PLMS) in children referred for evaluation of sleep disorders.
Design:
A retrospective analysis of all overnight polysomnograms (PSG) performed at a tertiary-level pediatric care facility.
Setting:
All PSG studies were performed in the pediatric sleep laboratory associated with the Alberta Children's Hospital in Calgary, AB, Canada. The pediatric sleep laboratory was situated in the Foothills Hospital Alberta Lung Association Sleep Center until August 2002. At that time, the pediatric sleep laboratory was relocated to the Alberta Children's Hospital.
Participants:
All children of any age undergoing PSG for any reason between October 1999 and March 2003.
Measurements And Results:
All PSG records were reviewed, and the following data was extracted: periodic limb movement index (PLM index), periodic limb movements with arousal index (PLM w/arousal index), apnea-hypopnea index (AHI), and patient demographics (age, sex, comorbidities). A total of 591 PSG studies were reviewed. Thirty-three of the 591 children (5.6%) had evidence of PLMs > 5 per hour. Twenty of the 33 (60.0%) had coexistent obstructive sleep apnea (AHI > 1/hour). Only 7 of the 591 children studied (1.2%) had evidence of PLM > 5 per hour with no other comorbidity. Two of 13 children with PLM > 5 per hour and no evidence of obstructive sleep apnea had attention-deficit/hyperactivity disorder. The prevalence of PLMS in the 28 of the 591 subjects with a preexisting diagnosis of ADHD was increased at 7.1%.
Conclusions:
PLMS is an uncommon disorder of childhood. In a select population at increased risk for having a sleep disorder, the prevalence of isolated PLMS is only 1.2%.
