title: Vagus nerve stimulation therapy induces changes in heart rate of children during sleep.
abstract: OBJECTIVE
  This study analyzed changes in the heart rates of children receiving vagus nerve stimulation (VNS) therapy for pharmacoresistant epilepsy.
  
  
  METHODS
  Changes in the heart rates of ten children receiving VNS therapy for pharmacoresistant epilepsy were evaluated with polysomnographic recordings, including electrocardiogram (ECG), EEG, thoraco-abdominal distension, nasal airflow, and VNS artifacts. Measurements during stimulation were compared with those at baseline for each patient.
  
  
  RESULTS
  While the VNS therapy pulse generator was delivering stimulation, the heart rates of four children increased significantly (p < 0.01), decreased for one child, and increased at the end of the stimulation for one child. The heart rates of four children did not change. Changes in heart rate varied during VNS, within stimulation cycles for individual children and from one child to another. Changes in heart rate differed between rapid eye movement (REM) and non-REM (NREM) sleep states. Respiratory changes (increases in frequency and decreases in amplitude) were concomitant with the changes in heart rate.
  
  
  CONCLUSIONS
  In this case series of children with pharmacoresistant epilepsy, cardiorespiratory variations occurred while the VNS therapy pulse generator was delivering stimulation. Understanding these variations may allow further optimization of VNS parameters.
authors.affiliation: GRAMFC, Faculté de Médecine, Amiens, France. boubker.zaaimi@u-picardie.fr
authors.forename: Boubker
authors.initials: B
authors.lastname: Zaaimi
authors.forename: Reinhard
authors.initials: R
authors.lastname: Grebe
authors.forename: Patrick
authors.initials: P
authors.lastname: Berquin
authors.forename: Fabrice
authors.initials: F
authors.lastname: Wallois
mesh_terms: D000293:Adolescent; D016477:Artifacts; D002648:Child; D004351:Drug Resistance; D004599:Electric Stimulation Therapy; D004562:Electrocardiography / Q000706:statistics & numerical data; D004569:Electroencephalography / Q000706:statistics & numerical data; D004827:Epilepsy / Q000628:therapy*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D017286:Polysomnography / Q000706:statistics & numerical data; D012143:Respiratory Physiological Phenomena; D012890:Sleep / Q000502:physiology*; D012894:Sleep Stages / Q000502:physiology; D012895:Sleep, REM / Q000502:physiology; D014630:Vagus Nerve / Q000502:physiology*