title: Pergolide increases the efficacy of cathodal direct current stimulation to reduce the amplitude of laser-evoked potentials in humans.
abstract: Transcranial direct current stimulation (tDCS) was recently reintroduced as a tool for inducing relatively long-lasting changes in cortical excitability in focal brain regions. Anodal stimulation over the primary motor cortex enhances cortical excitability, whereas cathodal stimulation decreases it. Prior studies have shown that enhancement of D2 receptor activity by pergolide consolidates tDCS-generated excitability diminution for up to 24 hours and that cathodal stimulation of the primary motor cortex diminishes experimentally induced pain sensation and reduces the N2-P2 amplitude of laser-evoked potentials immediately poststimulation. In the present study, we investigated the effect of pergolide and cathodal tDCS over the primary motor cortex on laser-evoked potentials and acute pain perception induced with a Tm:YAG laser in a double-blind, randomized, placebo-controlled, crossover study. The amplitude changes of laser-evoked potentials and subjective pain rating scores of 12 healthy subjects were analyzed prior to and following 15 minutes cathodal tDCS combined with pergolide or placebo intake at five different time points. Our results indicate that the amplitude of the N2 component was significantly reduced following cathodal tDCS for up to two hours. Additionally, pergolide prolonged the effect of the cathodal tDCS for up to 24 hours, and a significantly lowered pain sensation was observed for up to 40 minutes. Our study is a further step toward clinical application of cathodal tDCS over the primary motor cortex using pharmacological intervention to prolong the excitability-diminishing effect on pain perception for up to 24 hours poststimulation. Furthermore, it demonstrates the potential for repetitive daily stimulation therapy for pain patients.
authors: Department of Clinical Neurophysiology, Georg-August University, Göttingen, Germany. daniellaterney@yahoo.co.uk
authors: Daniella
authors: D
authors: Terney
authors: Inga
authors: I
authors: Bergmann
authors: Csaba
authors: C
authors: Poreisz
authors: Leila
authors: L
authors: Chaieb
authors: Klára
authors: K
authors: Boros
authors: Michael Andreas
authors: MA
authors: Nitsche
authors: Walter
authors: W
authors: Paulus
authors: Andrea
authors: A
authors: Antal
mesh_terms: D000328:Adult; D018491:Dopamine Agonists / Q000008:administration & dosage; D004558:Electric Stimulation / Q000379:methods*; D004566:Electrodes; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects* / Q000502:physiology*; D005260:Female; D006801:Humans; D007834:Lasers; D008297:Male; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology*; D010479:Pergolide / Q000008:administration & dosage*
chemical_list: D018491:Dopamine Agonists; D010479:Pergolide