Experimental Brain Research

, Volume 144, Issue 4, pp 475–482

Temporal summation of pain from skin, muscle and joint following nociceptive ultrasonic stimulation in humans

Authors

  • A. Wright
    • School of PhysiotherapyCurtin University of Technology
    • Laboratory for Experimental Pain Research, Center for Sensory-Motor InteractionAalborg University
  • I. I. Davies
    • School of PharmacyThe Queen’s University of Belfast
  • L. Arendt-Nielsen
    • Laboratory for Experimental Pain Research, Center for Sensory-Motor InteractionAalborg University
Research Article

DOI: 10.1007/s00221-002-1062-4

Cite this article as:
Wright, A., Graven-Nielsen, T., Davies, I.I. et al. Exp Brain Res (2002) 144: 475. doi:10.1007/s00221-002-1062-4

Abstract

This study investigated the phenomenon of temporal summation in response to repetitive focused ultrasound stimulation of skin, muscle and joint in human volunteers. Stimulation was carried out using a customdesigned, focused ultrasonic stimulator with a resonant frequency of 1.66 MHz. A series of stand-off attachments were used to ensure that the focal region of the ultrasound beam projected either cutaneousely, within the distal interphalangeal joint of the index finger, or within the first dorsal interosseous muscle. Stimulation was carried out using single pulses and trains of five pulses of different pulse durations (25 ms, 50 ms, 75 ms, 100 ms), and using single pulses and trains of five pulses (50 ms duration) at different frequencies (0.5 Hz, 1 Hz, 2 Hz, 3 Hz, 4 Hz, 5 Hz). Tactile perception thresholds, pain thresholds and summation pain thresholds were recorded. Temporal summation of pain could be elicited by stimulation of both skin, joint and muscle, although the influence of temporal summation appeared to be more pronounced for muscle stimulation. Muscle stimulation also required greater ultrasound intensity compared with joint and skin stimulation. Temporal summation could not be elicited by tactile, low-intensity stimulation. Focused ultrasound is a potent, noninvasive technique with which to investigate temporal summation from somatic structures. A number of factors may account for the higher intensities required to elicit pain in muscle and the increased rate of temporal summation. It is clear, however, that if temporal summation is more pronounced in muscle than other tissues then this may be an important factor contributing to pain in musculoskeletal syndromes.

Keywords

Muscle painSkin painJoint painFocused ultrasoundTemporal summation

Copyright information

© Springer-Verlag 2002