title: Focal Mechanical Vibration Does not Change Laser-Pain Perception and Laser-Evoked Potentials: A Pilot Study.
abstract: Nonpainful tactile and electrical stimulation of the large myelinated fibers reduces spontaneous pain and the amplitude of laser-evoked potentials (LEPs), which represent the most reliable technique to assess the nociceptive pathway function. Focal mechanical vibration stimulates the Aβ afferents selectively; thus, it is conceivable its action on nociceptive pathways.
  
  
  
  The aim of this study was to investigate the effect of vibratory stimuli, activating either both muscle and skin receptors or cutaneous afferents only on the LEPs and subjective laser-pain rating.
  
  
  
  Ten healthy volunteers were studied. The subjects were evaluated in two different sessions to test muscle and skin receptors or cutaneous afferents only. In each session, LEPs were recorded to stimulation of the dorsal hand skin in radial and ulnar territory bilaterally, while the vibratory stimulus was delivered on the radial territory of the right forearm.
  
  
  
  The results showed a substantial stability of the potential N1 and N2/P2 after the two protocols, with a declining trend from the initial to the last test of the same session, probably due to habituation. Accordingly, the laser-pain perception did not change during the experimental setting.
  
  
  
  We conclude that a vibratory stimulus is ineffective in reducing the laser-evoked potentials and laser-pain perception.
authors.affiliation: Department of Neurorehabilitation, Don Carlo Gnocchi Onlus Foundation, Milan, Italy.
authors.forename: Costanza
authors.initials: C
authors.lastname: Pazzaglia
authors.affiliation: Physical Medicine and Rehabilitation Division, Umberto I Hospital, Sapienza University, Rome, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Camerota
authors.affiliation: Physical Medicine and Rehabilitation Division, Umberto I Hospital, Sapienza University, Rome, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Celletti
authors.affiliation: Department of Geriatric, Neuroscience and Orthopaedic, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Ileana
authors.initials: I
authors.lastname: Minciotti
authors.affiliation: Department of Geriatric, Neuroscience and Orthopaedic, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Testani
authors.affiliation: Department of Neurorehabilitation, Don Carlo Gnocchi Onlus Foundation, Milan, Italy.|Department of Geriatric, Neuroscience and Orthopaedic, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Padua
authors.affiliation: Department of Neurology, Pediatric Hospital Bambino Gesù, Rome, Italy.|Center for Sensory-motor Interaction, Aalborg University, Aalborg, Denmark.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Valeriani
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D066331:Laser-Evoked Potentials; D008297:Male; D010146:Pain / Q000503:physiopathology; D010147:Pain Measurement; D058748:Pain Perception / Q000502:physiology*; D010865:Pilot Projects; D014732:Vibration; D055815:Young Adult
keywords: experimental pain model; focal mechanical vibration; laser-evoked potentials; pain perception