title: Respiratory hypoalgesia? Breath-holding, but not respiratory phase modulates nociceptive flexion reflex and pain intensity.
abstract: Several observations suggest that respiratory phase (inhalation vs. exhalation) and post-inspiratory breath-holds could modulate pain and the nociceptive reflex. This experiment aimed to investigate the role of both mechanisms. Thirty-two healthy participants received supra-threshold electrocutaneous stimulations to elicit both the Nociceptive Flexion Reflex (NFR) and pain, either during spontaneous inhalations or exhalations, or during three types of instructed breath-holds: following exhalation, at mid-inhalation and at full-capacity inhalation. Whether the electrocutaneous stimulus was applied during inhalation or exhalation did not affect the NFR or pain. Self-reported pain was reduced and the NFR was increased during breath-holding compared to spontaneous breathing. Whereas the type of breath-hold did not impact on self-reported pain, breath-holds at full-capacity inhalation and following exhalation were associated with a lower NFR amplitude compared to breath-holds at mid-inhalation. The present findings confirm that breath-holding can modulate pain (sensitivity) and suggest that both attentional distraction and changes in vagal activity may underlie the observed effects.
authors.affiliation: University of Leuven, Health Psychology, Leuven, Belgium. Electronic address: Hassan.Jafari@ppw.kuleuven.be.
authors.forename: Hassan
authors.initials: H
authors.lastname: Jafari
authors.affiliation: University of Leuven, Health Psychology, Leuven, Belgium.
authors.forename: Karlien
authors.initials: K
authors.lastname: Van de Broek
authors.affiliation: Institute of Neuroscience (IoNS), Université catholique de Louvain, Brussels, Belgium.
authors.forename: Léon
authors.initials: L
authors.lastname: Plaghki
authors.affiliation: University of Leuven, Health Psychology, Leuven, Belgium; Department of Clinical Psychological Science, Maastricht University, The Netherlands.
authors.forename: Johan W S
authors.initials: JW
authors.lastname: Vlaeyen
authors.affiliation: University of Leuven, Health Psychology, Leuven, Belgium.
authors.forename: Omer
authors.initials: O
authors.lastname: Van den Bergh
authors.affiliation: University of Leuven, Health Psychology, Leuven, Belgium.
authors.forename: Ilse
authors.initials: I
authors.lastname: Van Diest
mesh_terms: D000293:Adolescent; D000328:Adult; D062485:Breath Holding; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D009619:Nociceptors / Q000502:physiology*; D010146:Pain / Q000517:prevention & control*; D059408:Pain Management / Q000379:methods; D010147:Pain Measurement / Q000379:methods; D017288:Pain Threshold / Q000502:physiology*; D012018:Reflex / Q000502:physiology*; D015656:Respiratory Mechanics / Q000502:physiology*; D055815:Young Adult
keywords: Breath-hold; Breathing; Hypoalgesia; Nociceptive flexion reflex; Pain; Respiration