title: The relationship between nociceptive brain activity, spinal reflex withdrawal and behaviour in newborn infants.
abstract: Measuring infant pain is complicated by their inability to describe the experience. While nociceptive brain activity, reflex withdrawal and facial grimacing have been characterised, the relationship between these activity patterns has not been examined. As cortical and spinally mediated activity is developmentally regulated, it cannot be assumed that they are predictive of one another in the immature nervous system. Here, using a new experimental paradigm, we characterise the nociceptive-specific brain activity, spinal reflex withdrawal and behavioural activity following graded intensity noxious stimulation and clinical heel lancing in 30 term infants. We show that nociceptive-specific brain activity and nociceptive reflex withdrawal are graded with stimulus intensity (p < 0.001), significantly correlated (r = 0.53, p = 0.001) and elicited at an intensity that does not evoke changes in clinical pain scores (p = 0.55). The strong correlation between reflex withdrawal and nociceptive brain activity suggests that movement of the limb away from a noxious stimulus is a sensitive indication of nociceptive brain activity in term infants. This could underpin the development of new clinical pain assessment measures.
authors.affiliation: Department of Paediatrics, University of Oxford, OX3 9DU, UK.
authors.forename: Caroline
authors.initials: C
authors.lastname: Hartley
authors.affiliation: Nuffield Department of Clinical Neurosciences, University of Oxford, OX3 9DU, UK.
authors.forename: Sezgi
authors.initials: S
authors.lastname: Goksan
authors.affiliation: Nuffield Department of Clinical Neurosciences, University of Oxford, OX3 9DU, UK.
authors.forename: Ravi
authors.initials: R
authors.lastname: Poorun
authors.affiliation: Department of Paediatrics, University of Oxford, OX3 9DU, UK.
authors.forename: Kelly
authors.initials: K
authors.lastname: Brotherhood
authors.affiliation: Department of Paediatrics, University of Oxford, OX3 9DU, UK.
authors.forename: Gabriela Schmidt
authors.initials: GS
authors.lastname: Mellado
authors.affiliation: Department of Paediatrics, University of Oxford, OX3 9DU, UK.
authors.forename: Fiona
authors.initials: F
authors.lastname: Moultrie
authors.affiliation: Nuffield Department of Anaesthesia, John Radcliffe Hospital, OX3 9DU, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Rogers
authors.affiliation: Department of Paediatrics, University of Oxford, OX3 9DU, UK.
authors.forename: Eleri
authors.initials: E
authors.lastname: Adams
authors.affiliation: Department of Paediatrics, University of Oxford, OX3 9DU, UK.
authors.forename: Rebeccah
authors.initials: R
authors.lastname: Slater
mesh_terms: D001921:Brain / Q000502:physiology*; D004569:Electroencephalography; D004576:Electromyography; D006801:Humans; D007231:Infant, Newborn; D059225:Nociception / Q000502:physiology*; D033281:Nontherapeutic Human Experimentation; D010812:Physical Stimulation; D012018:Reflex / Q000502:physiology*; D013116:Spinal Cord / Q000502:physiology