Transcranial direct current stimulation over somatosensory cortex decreases experimentally induced acute pain perception.
OBJECTIVE
Multiple cortical areas including the primary somatosensory cortex are known to be involved in nociception. The aim of this study was to investigate the effect of transcranial direct current stimulation (tDCS) that modulates the cortical excitability painlessly and noninvasively, over somatosensory cortex on acute pain perception induced with a Tm:YAG laser.


METHODS
Subjective pain rating scores and amplitude changes of the N1, N2, and P2 components of laser-evoked potentials of 10 healthy participants were analyzed before and after anodal, cathodal, and sham tDCS.


RESULTS
Our results demonstrate that cathodal tDCS significantly diminished pain perception and the amplitude of the N2 component when the contralateral hand to the side of tDCS was laser-stimulated, whereas anodal and sham stimulation conditions had no significant effect.


CONCLUSIONS
Our study highlights the antinociceptive effect of this technique and may contribute to the understanding of the mechanisms underlying pain relief. The pharmacologic prolongation of the excitability-diminishing after-effects would render the method applicable to different patient populations with chronic pain.
Antal
Andrea
A
Department of Clinical Neurophysiology, Georg-August University, Robert Koch Strasse 40, 37075 Göttingen, Germany. AAntal@gwdg.de
Brepohl
Nadine
N
Poreisz
Csaba
C
Boros
Klara
K
Csifcsak
Gabor
G
Paulus
Walter
W
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D003627:Data Interpretation, Statistical; D004558:Electric Stimulation; D004569:Electroencephalography; D004594:Electrophysiology; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007834:Lasers; D008297:Male; D010146:Pain / Q000503:physiopathology / Q000523:psychology*; D011601:Psychophysics; D013003:Somatosensory Cortex / Q000502:physiology*