A novel method of eliciting pain-related potentials by transcutaneous electrical stimulation.
BACKGROUND
Electrophysiological techniques such as laser and contact heat evoked pain-related potentials are very useful for studying trigeminal and somatic pain transmission in humans. These methods are, however, partly invasive, expensive, and therefore not available for broad clinical use. We recently proposed a novel technique of noninvasive transcutaneous electrical stimulation.


OBJECTIVE
To elicit pain-related evoked potentials (PREP) by using a concentric planar electrode and demonstrate their nociceptive specificity.


METHODS
We registered PREP following stimulation of the forehead and hand in 14 healthy volunteers. Latencies, peak-to-peak amplitudes, and conduction velocities of nociceptive fibers have been estimated. Effects of temporal and spatial summation and of cutaneous anesthesia were evaluated.


RESULTS
Stimulation with the concentric planar electrode produced pinprick-like painful sensation. Cutaneous anesthesia led to abolishment of PREP responses. Estimated mean conduction velocity was 11.61 +/- 5.12 m/s, which corresponded well with conduction via A-delta fibers. Spatial as well as temporal summation resulted in a parallel increase of perceived pain intensity and PREP amplitudes.


CONCLUSIONS
The technique is noninvasive, affordable, and easy to perform and allows quantitative assessment of human nociceptive pathways.
Katsarava
Zaza
Z
University of Essen, Department of Neurology, Germany.
Ayzenberg
Ilya
I
Sack
Florian
F
Limmroth
Volker
V
Diener
Hans-Christoph
HC
Kaube
Holger
H
D000328:Adult; D000772:Anesthesia, Local; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009431:Neural Conduction / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology; D009619:Nociceptors / Q000502:physiology; D010146:Pain / Q000503:physiopathology*; D010147:Pain Measurement; D004561:Transcutaneous Electric Nerve Stimulation