Premium
Deep continuous theta burst stimulation of the operculo‐insular cortex selectively affects Aδ‐fibre heat pain
Author(s) -
Lenoir Cédric,
Algoet Maxime,
Mouraux André
Publication year - 2018
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jp276359
Subject(s) - ctbs , neuromodulation , insular cortex , stimulation , transcranial magnetic stimulation , neuroscience , deep transcranial magnetic stimulation , nociception , somatosensory system , psychology , motor cortex , medicine , primary motor cortex , receptor
Key points Deep continuous theta burst stimulation (cTBS) of the right operculo‐insular cortex delivered with a double cone coil selectively impairs the ability to perceive thermonociceptive input conveyed by Aδ‐fibre thermonociceptors without concomitantly affecting the ability to perceive innocuous warm, cold or vibrotactile sensations. Unlike deep cTBS, superficial cTBS of the right operculum delivered with a figure‐of‐eight coil does not affect the ability to perceive thermonociceptive input conveyed by Aδ‐fibre thermonociceptors. The effect of deep operculo‐insular cTBS on the perception of Aδ‐fibre input was present at both the contralateral and the ipsilateral hand. The magnitude of the increase in Aδ‐heat detection threshold induced by the deep cTBS was significantly correlated with the intensity of the cTBS pulses. Deep cTBS delivered over the operculo‐insular cortex is associated with a risk of transcranial magnetic stimulation‐induced seizure.Abstract Previous studies have suggested a pivotal role of the insular cortex in nociception and pain perception. Using a double‐cone coil designed for deep transcranial magnetic stimulation, our objective was to assess (1) whether continuous theta burst stimulation (cTBS) of the operculo‐insular cortex affects differentially the perception of different types of thermal and mechanical somatosensory inputs, (2) whether the induced after‐effects are lateralized relative to the stimulated hemisphere, and (3) whether the after‐effects are due to neuromodulation of the insula or neuromodulation of the more superficial opercular cortex. Seventeen participants took part in two experiments. In Experiment 1, thresholds and perceived intensity of Aδ‐ and C‐fibre heat pain elicited by laser stimulation, non‐painful cool sensations elicited by contact cold stimulation and mechanical vibrotactile sensations were assessed at the left hand before, immediately after and 20 min after deep cTBS delivered over the right operculo‐insular cortex. In Experiment 2, Aδ‐fibre heat pain and vibrotactile sensations elicited by stimulating the contralateral and ipsilateral hands were evaluated before and after deep cTBS or superficial cTBS delivered using a flat figure‐of‐eight coil. Only the threshold to detect Aδ‐fibre heat pain was significantly increased 20 min after deep cTBS. This effect was present at both hands. No effect was observed after superficial cTBS. Neuromodulation of the operculo‐insular cortex using deep cTBS induces a bilateral reduction of the ability to perceive Aδ‐fibre heat pain, without concomitantly affecting the ability to perceive innocuous warm, cold or vibrotactile sensations.