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Updated: Jun 12, 2026
Corticospinal Excitability Modulation During Action Observation
Published on: December 31, 2013
Exploring pain-motor dynamics: preliminary insights through exploration of descending inhibition and corticospinal
Arnaud Duport1,2,3, Hervé Devanne3, Guillaume Léonard1,2
1Research Centre on Aging, CIUSSS de l'Estrie-CHUS, Sherbrooke, QC, Canada.
Introduction:
Previous studies have linked endogenous pain modulation and corticospinal excitability (CSE), but methodological limitations and overlooking psychological factors may have constrained interpretations. This study aimed to evaluate the interaction between CSE excitability in different muscles and endogenous pain modulation, and to determine whether kinesiophobia and pain catastrophizing modulate this interaction.
Methods:
Twenty-one pain-free participants completed questionnaires on kinesiophobia and pain catastrophizing. Conditioned pain modulation (CPM) was used to assess endogenous pain modulation. Transcranial magnetic stimulation was used to assess the pain-induced modulation in CSE excitability, focusing on slope, S50 and the maximum response parameters of input-output curves (plateau) for the anterior deltoid (AD) and first dorsal interosseous (FDI) muscles, first in pain-free then in painful condition induced by the application of capsaicin cream to the shoulder.
Results:
A significant correlation was found between the plateau of the AD input-output curves measured at baseline (pain-free condition) and CPM responses (rS = .56, p = 0.01), suggesting that higher maximal corticospinal output is associated with more effective endogenous pain modulation. Pain-induced changes in FDI slope and CPM responses were strongly correlated (rS = -.75, p < 0.001), indicating that individuals with the most effective endogenous pain inhibition mechanisms were those with the greatest increase in CSE. Finally, kinesiophobia was found to alter the association between pain-induced changes in CSE in AD (S50 shift) and CPM response, shedding new light on the influence of psychological factors on pain-induced CSE alterations and their link with descending pain inhibition.
Discussion:
These findings underscore the complex interplay between corticospinal projections, pain modulation, and psychological factors, reinforcing the need for further investigation.
