title: Neonatal somatosensory evoked potentials persist during hypothermia.
abstract: OBJECTIVE
  Treatment with therapeutic hypothermia has challenged the use of amplitude-integrated electroencephalography in predicting outcomes after perinatal asphyxia. In this study, we assessed the feasibility and gain of somatosensory evoked potentials (SEP) during hypothermia.
  
  
  METHODS
  This retrospective study comprised neonates from 35 + 6 to 42 + 2 gestational weeks and treated for asphyxia or hypoxic-ischaemic encephalopathy at Helsinki University Hospital between 14 February 2007 and 23 December 2009. This period was partly before the introduction of routine therapeutic hypothermia, which enabled us to include normothermic neonates who would these days receive hypothermia treatment. We analysed SEPs from 47 asphyxiated neonates and compared the results between 23 normothermic and 24 hypothermic neonates.
  
  
  RESULTS
  Our data showed that hypothermia led to SEP latencies lengthening by a few milliseconds, but the essential gain for predicting outcomes by SEPs was preserved during hypothermia. Of the 24 hypothermic neonates, bilaterally absent SEPs were associated with poor outcome in 2/2 neonates, normal SEPs were associated with good outcomes in 13/15 neonates and 5/7 neonates with unilaterally absent or grossly delayed SEPs had a poor outcome.
  
  
  CONCLUSIONS
  Our findings indicated that SEPs were a reliable tool for evaluating the somatosensory system in asphyxiated neonates in both normothermic and hypothermic conditions.
authors.affiliation: Department of Clinical Neurophysiology, Children's Hospital, HUS Medical Imaging Center, University of Helsinki and Helsinki University Hospital (HUH), Helsinki, Finland.
authors.forename: Päivi
authors.initials: P
authors.lastname: Nevalainen
authors.affiliation: Department of Clinical Neurophysiology, Children's Hospital, HUS Medical Imaging Center, University of Helsinki and Helsinki University Hospital (HUH), Helsinki, Finland.
authors.forename: Leena
authors.initials: L
authors.lastname: Lauronen
authors.affiliation: Department of Pediatrics, Children's Hospital, University of Helsinki and HUH, Helsinki, Finland.
authors.forename: Marjo
authors.initials: M
authors.lastname: Metsäranta
authors.affiliation: Department of Child Neurology, Children's Hospital, University of Helsinki and HUH, Helsinki, Finland.
authors.forename: Tuula
authors.initials: T
authors.lastname: Lönnqvist
authors.affiliation: Department of Clinical Neurophysiology, Children's Hospital, HUS Medical Imaging Center, University of Helsinki and Helsinki University Hospital (HUH), Helsinki, Finland.
authors.forename: Eero
authors.initials: E
authors.lastname: Ahtola
authors.affiliation: Department of Clinical Neurophysiology, Children's Hospital, HUS Medical Imaging Center, University of Helsinki and Helsinki University Hospital (HUH), Helsinki, Finland.
authors.forename: Sampsa
authors.initials: S
authors.lastname: Vanhatalo
mesh_terms: D001238:Asphyxia Neonatorum / Q000628:therapy*; D005073:Evoked Potentials, Somatosensory; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D006979:Hyperthermia, Induced; D020925:Hypoxia-Ischemia, Brain / Q000628:therapy*; D007231:Infant, Newborn; D008297:Male; D012189:Retrospective Studies
keywords: Asphyxia; Brain monitoring; Hypoxic-ischaemic encephalopathy; Newborn infant; Somatosensory evoked potentials