title: Periodic limb movements and restless legs syndrome in children with a history of prematurity.
abstract: Little is known about the pediatric population at an increased risk of restless legs syndrome (RLS) and periodic limb movement disorder (PLMD). Polysomnographic data from the Caffeine for Apnea of Prematurity-Sleep (CAPS) study showed a high prevalence of elevated periodic limb movement index (PLMI) in a cohort of ex-preterm children, but the clinical importance of this finding, such as association with RLS, is unknown. We hypothesized that ex-preterm children would have a high prevalence of RLS and PLMD.
  
  
  
  Ex-preterm children enrolled in CAPS, now aged 5-12 years, completed home polysomnography (PSG) and standardized questionnaires. A diagnosis of RLS or PLMD was established by participants meeting the International Classification of Sleep Disorders, 3rd edition, criteria based on questionnaires and polysomnograms. The clinically available serum ferritin levels were assessed.
  
  
  
  In total, 167 participants underwent polysomnography and completed all questionnaires. The overall prevalence of RLS was 14/167 (8.4%). An additional 13 subjects (7.8%) were found to have PLMD. Of the 26 participants who had PLMI > 5/h, seven (26.9%) had RLS and 13 (50%) had PLMD. The serum ferritin levels were <50 mcg/L (range -38.4) for all eight participants referred for testing.
  
  
  
  Children with a history of prematurity have a high prevalence of RLS, particularly those with elevated periodic limb movements. Iron deficiency likely contributes to RLS and PLMD symptoms in this population. Clinicians evaluating ex-preterm children with sleep disturbances should evaluate for RLS and PLMD. Further studies including serum ferritin evaluation are required to confirm these findings.
authors.affiliation: Sleep Center, Children's Hospital of Philadelphia and the University of Pennsylvania School of Medicine, Philadelphia, PA, USA. Electronic address: cieloc@email.chop.edu.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Cielo
authors.affiliation: Sleep Center, Children's Hospital of Philadelphia and the University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Lourdes M
authors.initials: LM
authors.lastname: DelRosso
authors.affiliation: Sleep Center, Children's Hospital of Philadelphia and the University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Ignacio E
authors.initials: IE
authors.lastname: Tapia
authors.affiliation: The Ritchie Centre, Hudson Institute of Medical Research, Department of Paediatrics, Monash University, Melbourne, Victoria, Australia.
authors.forename: Sarah N
authors.initials: SN
authors.lastname: Biggs
authors.affiliation: The Ritchie Centre, Hudson Institute of Medical Research, Department of Paediatrics, Monash University, Melbourne, Victoria, Australia.
authors.forename: Gillian M
authors.initials: GM
authors.lastname: Nixon
authors.affiliation: Department of Pediatrics, National Jewish Health, Denver, CO, USA.
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Meltzer
authors.affiliation: Sleep Center, Children's Hospital of Philadelphia and the University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Joel
authors.initials: J
authors.lastname: Traylor
authors.affiliation: Clinical and Translational Research Center, Children's Hospital of Philadelphia and the University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Sleep Center, Children's Hospital of Philadelphia and the University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
authors.forename: Carole L
authors.initials: CL
authors.lastname: Marcus
mesh_terms: D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005293:Ferritins / Q000097:blood; D006801:Humans; D008297:Male; D020189:Nocturnal Myoclonus Syndrome / Q000453:epidemiology*; D011247:Pregnancy; D047928:Premature Birth; D015995:Prevalence; D012148:Restless Legs Syndrome / Q000453:epidemiology*
chemical_list: D005293:Ferritins
keywords: Children; Periodic limb movement disorder; Prematurity; Restless legs syndrome