Experimental Pain Decreases Corticomuscular Coherence in a Force- But Not a Position-Control Task

Peter C Poortvliet; Kylie J Tucker; Simon Finnigan; Dion Scott; Paul W Hodges

doi:10.1016/j.jpain.2018.08.012

Experimental Pain Decreases Corticomuscular Coherence in a Force- But Not a Position-Control Task

J Pain. 2019 Feb;20(2):192-200. doi: 10.1016/j.jpain.2018.08.012. Epub 2018 Sep 25.

Authors

Peter C Poortvliet¹, Kylie J Tucker², Simon Finnigan³, Dion Scott⁴, Paul W Hodges⁵

Affiliations

¹ Centre for Clinical Research Excellence in Spinal Pain, Injury and Health, School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Australia; Centre for Sensorimotor Performance, School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, Australia; Asia-Pacific Centre for Neuromodulation, Queensland Brain Institute, The University of Queensland, Brisbane, Australia.
² Centre for Clinical Research Excellence in Spinal Pain, Injury and Health, School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Australia; School of Biomedical Sciences, The University of Queensland, Brisbane, Australia.
³ Centre for Clinical Research, Royal Brisbane & Women's Hospital, The University of Queensland, Brisbane, Australia.
⁴ Centre for Clinical Research Excellence in Spinal Pain, Injury and Health, School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Australia.
⁵ Centre for Clinical Research Excellence in Spinal Pain, Injury and Health, School of Health and Rehabilitation Sciences, The University of Queensland, Brisbane, Australia. Electronic address: p.hodges@uq.edu.au.

PMID: 30266268
DOI: 10.1016/j.jpain.2018.08.012

Abstract

Differences in neural drive could explain variation in adaptation to acute pain between postural and voluntary motor actions. We investigated whether cortical contributions, quantified by corticomuscular coherence, are affected differently by acute experimental pain in more posturally focused position-control tasks and voluntary focused force-control tasks. Seventeen participants performed position- and force-control contractions with matched loads (10% maximum voluntary contraction) before and during pain (injection of hypertonic saline into the infrapatellar fat pad of the knee). Surface electromyography (EMG) of right knee extensor and flexor muscles was recorded. Electroencephalography (EEG) was recorded using a 128-channel sensor net. Corticomuscular coherence was calculated between 4 EEG electrodes that approximated the contralateral motor cortical area, and EMG. Coherence, EEG, EMG, and target performance accuracy were compared between task types and pain states. Before pain, coherence EEG and EMG did not differ between tasks. During pain, EMG increased in both tasks, but the force-control task showed greater pain interference (decreased coherence, higher EEG frequencies, and increased force fluctuations). Neural substrates of motor performance of postural functions are changed uniquely by experimental pain, which might be explained by differences in cortical demands. Our results provide new insights into the mechanisms of motor adaptations during acute pain. PERSPECTIVE: Understanding of the mechanisms underlying adaptations to motor function in acute pain is incomplete. Experimental work almost exclusively focuses on voluntary motor actions, but these adaptations may be inappropriate for postural actions. Our results show less pain-related interference in brain activity and its relationship to muscle activation during position-control tasks.

Keywords: Corticomuscular coherence; electroencephalography; electromyography; experimental pain; postural control.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Electroencephalography
Electromyography
Female
Humans
Male
Motor Activity / physiology*
Motor Cortex / physiology*
Muscle, Skeletal / physiology*
Postural Balance / physiology*