title: The effect of sleep restriction on laser evoked potentials, thermal sensory and pain thresholds and suprathreshold pain in healthy subjects.
abstract: OBJECTIVE
  Sleep restriction seems to change our experience of pain and reduce laser evoked potential (LEP) amplitudes. However, although LEP-habituation abnormalities have been described in painful conditions with comorbid sleep impairment, no study has previously measured the effect of sleep restriction on LEP-habituation, pain thresholds, and suprathreshold pain.
  
  
  METHODS
  Sixteen males and seventeen females (aged 18-31years) were randomly assigned to either two nights of delayed bedtime and four hours sleep (partial sleep deprivation) or nine hours sleep. The study subjects slept at home, and the sleep was measured with actigraphy both nights and polysomnography the last night. LEP, thermal thresholds and suprathreshold pain ratings were obtained the day before and the day after intervention. The investigator was blinded. ANOVA was used to evaluate the interaction between sleep restriction and day for each pain-related variable.
  
  
  RESULTS
  LEP-amplitude decreased after sleep restriction (interaction p=0.02) compared to subjects randomized to nine hours sleep. LEP-habituation was similar in both groups. Thenar cold pain threshold decreased after sleep restriction (interaction p=0.009). Supra-threshold heat pain rating increased temporarily 10s after stimulus onset after sleep restriction (interaction p=0.01), while it did not change after nine hours sleep.
  
  
  CONCLUSIONS
  Sleep restriction reduced the CNS response to pain, while some of the subjective pain measures indicated hyperalgesia.
  
  
  CONCLUSIONS
  Since LEP-amplitude is known to reflect both CNS-pain-specific processing and cognitive attentive processing, our results suggest that hyperalgesia after sleep restriction might partly be caused by a reduction in cortical cognitive or perceptual mechanisms, rather than sensory amplification.
authors.affiliation: Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, MTFS, N-7489 Trondheim, Norway. Electronic address: siv.steinsmo@gmail.com.
authors.forename: Siv Steinsmo
authors.initials: SS
authors.lastname: Ødegård
authors.affiliation: Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, MTFS, N-7489 Trondheim, Norway.
authors.forename: Petter Moe
authors.initials: PM
authors.lastname: Omland
authors.affiliation: Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, MTFS, N-7489 Trondheim, Norway; Department of Work Psychology and Physiology, National Institute of Occupational Health, Oslo, Norway; Department of Neurology, Section for Clinical Neurophysiology, Oslo University Hospital - Ullevål, Oslo, Norway.
authors.forename: Kristian Bernhard
authors.initials: KB
authors.lastname: Nilsen
authors.affiliation: Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, MTFS, N-7489 Trondheim, Norway; Norwegian National Headache Centre, Section of Neurology, St. Olavs Hospital, N-7006 Trondheim, Norway.
authors.forename: Marit
authors.initials: M
authors.lastname: Stjern
authors.affiliation: Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, MTFS, N-7489 Trondheim, Norway; Norwegian National Headache Centre, Section of Neurology, St. Olavs Hospital, N-7006 Trondheim, Norway.
authors.forename: Gøril Bruvik
authors.initials: GB
authors.lastname: Gravdahl
authors.affiliation: Department of Neuroscience, Faculty of Medicine, Norwegian University of Science and Technology, MTFS, N-7489 Trondheim, Norway; Norwegian National Headache Centre, Section of Neurology, St. Olavs Hospital, N-7006 Trondheim, Norway.
authors.forename: Trond
authors.initials: T
authors.lastname: Sand
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D066331:Laser-Evoked Potentials / Q000502:physiology*; D008297:Male; D010146:Pain / Q000175:diagnosis / Q000503:physiopathology*; D010147:Pain Measurement / Q000379:methods*; D017288:Pain Threshold / Q000502:physiology*; D017286:Polysomnography / Q000379:methods; D012892:Sleep Deprivation / Q000175:diagnosis / Q000503:physiopathology*; D013697:Thermosensing / Q000502:physiology*; D055815:Young Adult
keywords: Evoked potentials; Habituation; LEP; Laser evoked potential; Pain thresholds; Partial sleep deprivation; Sleep restriction; Suprathreshold pain