Improvement of Parasomnias After Treatment of Restless Leg Syndrome/ Periodic Limb Movement Disorder in Children

J Clin Sleep Med. 2019 May 15;15(5):743-748. doi: 10.5664/jcsm.7766.


Study objectives: Previous studies have shown that non-rapid eye movement (NREM) sleep parasomnias commonly coexist with restless legs syndrome (RLS) and periodic limb movement disorder (PLMD) in children, leading to speculation that RLS/PLMD may precipitate or worsen parasomnias. However, there are limited data about the effect of the treatment of RLS/PLMD on parasomnias in children. Hence, we performed this study to determine whether the treatment of RLS/PLMD with oral iron therapy is associated with improvement of parasomnias in children.

Methods: A retrospective database was created for children with RLS/PLMD who were treated with iron therapy. These participants were followed for at least 1 year at Cincinnati Children's Hospital Medical Center. All participants had ferritin level testing and were treated with iron therapy. In addition, all participants underwent polysomnography before starting iron therapy for RLS/PLMD except for one participant who was already on iron but required a higher dose. Most participants underwent polysomnography after iron therapy.

Results: A total of 226 participants were identified with the diagnosis of RLS/PLMD. Of these, 50 had parasomnias and 30 of them were treated with iron therapy. Of the 30 participants, RLS symptoms improved in 15 participants (50%) and resolution of parasomnias was noted in 12 participants (40%) participants after iron therapy. Repeat polysomnography after iron therapy was performed in 21 participants (70%). After iron therapy, there was a significant decrease in periodic limb movement index (17.2 ± 8.8 [before] versus 6.7 ± 7.3 [after] events/h, P < .001). In addition, there were significant decreases in PLMS (24.52 ± 9.42 [before] versus 7.50 ± 7.18 [after] events/h, P < .0001), PLMS-related arousals (4.71 ± 1.81 [before] versus 1.35 ± 1.43 [after] events/h, P < .0001), and total arousals (11.65 ± 5.49 [before] versus 8.94 ± 3.65 [after] events/h, P < .01) after iron therapy.

Conclusions: Parasomnias are common in our cohort of children with RLS/PLMD. Iron therapy was associated with a significant improvement in periodic limb movement index, RLS symptoms, and resolution of a significant proportion of NREM sleep parasomnias, suggesting that RLS/PLMD may precipitate NREM sleep parasomnia.

Keywords: parasomnias; periodic limb movement disorder; restless leg syndrome.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Child
  • Cohort Studies
  • Female
  • Humans
  • Iron / therapeutic use*
  • Male
  • Nocturnal Myoclonus Syndrome / complications*
  • Nocturnal Myoclonus Syndrome / drug therapy*
  • Nocturnal Myoclonus Syndrome / physiopathology
  • Parasomnias / complications
  • Parasomnias / drug therapy
  • Parasomnias / physiopathology
  • Polysomnography / methods
  • Restless Legs Syndrome / complications*
  • Restless Legs Syndrome / drug therapy*
  • Restless Legs Syndrome / physiopathology
  • Retrospective Studies
  • Treatment Outcome


  • Iron