Cerebral responses to innocuous somatic pressure stimulation following aerobic exercise rehabilitation in chronic pain patients: a functional magnetic resonance imaging study

Abstract

Objective The purpose of this research was to assess the functional brain activity and perceptual rating of innocuous somatic pressure stimulation before and after exercise rehabilitation in patients with chronic pain. Materials and methods Eleven chronic pain patients and eight healthy pain-free controls completed 12 weeks of supervised aerobic exercise intervention. Perceptual rating of standardized somatic pressure stimulation (2 kg) on the right anterior mid-thigh and brain responses during functional magnetic resonance imaging (fMRI) were assessed at pre- and postexercise rehabilitation. Results There was a significant difference in the perceptual rating of innocuous somatic pressure stimulation between the chronic pain and control groups ( P =0.02) but no difference following exercise rehabilitation. Whole brain voxel-wise analysis with correction for multiple comparisons revealed trends for differences in fMRI responses between the chronic pain and control groups in the superior temporal gyrus (chronic pain > control, corrected P =0.30), thalamus, and caudate (control > chronic, corrected P =0.23). Repeated measures of the regions of interest (5 mm radius) for blood oxygen level-dependent signal response revealed trend differences for superior temporal gyrus ( P =0.06), thalamus ( P =0.04), and caudate ( P =0.21). Group-by-time interactions revealed trend differences in the caudate ( P =0.10) and superior temporal gyrus ( P =0.29). Conclusion Augmented perceptual and brain responses to innocuous somatic pressure stimulation were shown in the chronic pain group compared to the control group; however, 12-weeks of exercise rehabilitation did not significantly attenuate these responses.

Does Conservative Treatment Change the Brain in Patients with Chronic Musculoskeletal Pain? A Systematic Review

“…The study of Micalos et al (33) did not show any statistically significant pressure-induced brain activity changes following exercise therapy in a sample of chronic musculoskeletal pain patients. Only group by time trends towards activity changes in the superior temporal gyrus and caudate nucleus were shown.…”

“…Two of the included studies applied physical exercise therapy (30,33). Flodin et al (30) included fibromyalgia patients, which were evaluated by restingstate functional connectivity of 6 predefined seed regions.…”

“…Becerra et al (28) evaluated the changes in multiple resting-state networks pre-to-post-treatment, Simons et al (36) investigated functional connectivity changes, and Erpelding et al (35) looked at gray matter morphological changes as well as functional connectivity changes. Lastly, 2 studies applied exercise therapy; Flodin et al (30) evaluated the effects of exercise therapy with resting-state fMRI within fibromyalgia patients and Micalos et al (33) evaluated the effects of exercise therapy with pressureinduced fMRI in chronic musculoskeletal pain patients.…”

Endurance Performance is Influenced by Perceptions of Pain and Temperature: Theory, Applications and Safety Considerations

“…Indeed, an improvement in pain tolerance has been an outcome of aerobic training programs in previously untrained individuals [23][24][25], which the authors attributed predominantly to psychological adaptations to training (although this was not measured). The increased pain tolerance could have arisen as a result of diminished signalling in response to the noxious stimulus [26][27][28], but this desensitisation of the nociceptors is hard to measure and unlikely given that these studies also observed no change in pain threshold. A more likely explanation is that exposure to frequent and unpleasant sensory experiences during aerobic training permits the participants to develop a means of coping and a tolerance to these sensations.…”

Differential pain response at local and remote muscle sites following aerobic cycling exercise at mild and moderate intensity

“…Hypoalgesic effects have been shown with exercise duration of 30 min but not at 10 min (Hoffman et al 2004 ). Research on the effect of exercise on pain response is of interest due to evaluating changes in the function of the pain inhibitory system (Micalos et al 2014 ). Understanding the function of the pain inhibitory system is beneficial for improving the prescription of exercise in chronic pain therapy (Carbonell-Baeza et al 2010 ).…”