title: Periictal activity in cooled asphyxiated neonates with seizures.
abstract: OBJECTIVE
  Seizures are common in critically ill neonates. Both seizures and antiepileptic treatments may lead to short term complications and worsen the outcomes. Predicting the risks of seizure reoccurrence could enable individual treatment regimens and better outcomes. We aimed to identify EEG signatures of seizure reoccurrence by investigating periictal electrographic features and spectral power characteristics in hypothermic neonates with hypoxic-ischemic encephalopathy (HIE) with or without reoccurrence of seizures on rewarming.
  
  
  METHODS
  We recruited five consecutive HIE neonates, submitted to continuous EEG monitoring, with high seizure burden (>20% per hour) while undergoing therapeutic hypothermia. Two of them had reoccurrence of seizures on rewarming. We performed quantitative analysis of fifteen artifact-free consecutive seizures to appreciate spectral power changes between the interictal, preictal and ictal periods, separately for each patient. Visual analysis allowed description of electrographic features associated with ictal events.
  
  
  RESULTS
  Every patient demonstrated a significant increase in overall spectral power from the interictal to preictal and ictal periods (p<0.01). Alpha power increase was more pronounced in the two patients with reoccurrence of seizures on rewarming and significant when comparing both interictal-to-preictal and interictal-to-ictal periods. This alpha activity increase could be also appreciated using visual analysis and distinguished neonates with and without seizure reoccurrence.
  
  
  CONCLUSIONS
  This distinct alpha activity preceding ictal onset could represent a biomarker of propensity for seizure reoccurrence in neonates. Future studies should be performed to confirm whether quantitative periictal characteristics and electrographic features allow predicting the risks of seizure reoccurrence in HIE neonates and other critically ill patients.
authors.affiliation: Division of Neurology, CHU Sainte Justine, Department of Neurosciences and Paediatrics, University of Montreal, Montreal, Canada; CHU Sainte-Justine Research Center, Montreal, Canada.
authors.forename: Philippe
authors.initials: P
authors.lastname: Major
authors.affiliation: Division of Neurology, CHU Sainte Justine, Department of Neurosciences and Paediatrics, University of Montreal, Montreal, Canada.
authors.forename: Anne
authors.initials: A
authors.lastname: Lortie
authors.affiliation: Department of Radiology, CHU Sainte Justine, University of Montreal, Montreal, Canada; CHU Sainte-Justine Research Center, Montreal, Canada.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Dehaes
authors.affiliation: Neonatology, CHU Sainte Justine, Department of Paediatrics, University of Montreal, Montreal, Canada; CHU Sainte-Justine Research Center, Montreal, Canada.
authors.forename: Gregory Anton
authors.initials: GA
authors.lastname: Lodygensky
authors.affiliation: Department of Psychology, University of Montreal, Montreal, Canada; CHU Sainte-Justine Research Center, Montreal, Canada.
authors.forename: Anne
authors.initials: A
authors.lastname: Gallagher
authors.affiliation: Division of Neurology, CHU Sainte Justine, Department of Neurosciences and Paediatrics, University of Montreal, Montreal, Canada; CHU Sainte-Justine Research Center, Montreal, Canada.
authors.forename: Lionel
authors.initials: L
authors.lastname: Carmant
authors.affiliation: Division of Neurology, CHU Sainte Justine, Department of Neurosciences and Paediatrics, University of Montreal, Montreal, Canada; CHU Sainte-Justine Research Center, Montreal, Canada. Electronic address: ala.birca@gmail.com.
authors.forename: Ala
authors.initials: A
authors.lastname: Birca
mesh_terms: D001921:Brain / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced; D020925:Hypoxia-Ischemia, Brain / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy*; D007231:Infant, Newborn; D008297:Male; D011379:Prognosis; D012189:Retrospective Studies; D012640:Seizures / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy*
keywords: Critically ill neonates; Hypoxic-ischemic encephalopathy; Seizure prediction; Seizure reoccurrence; Spectral power; Therapeutic hypothermia