Cognitive Inhibition Correlates with Exercise-Induced Hypoalgesia After Aerobic Bicycling in Pain-Free Participants.

PURPOSE: Exercise-induced hypoalgesia (EIH) is the short-term reduction of pain sensitivity after a single bout of exercise. Descending pain inhibition has been proposed to at least partly underlie EIH. Cognitive inhibition is the ability to inhibit a pre-potent response and has in turn been associated with descending pain inhibition, as indexed by conditioned pain modulation. Therefore, we hypothesized that cognitive inhibition is associated with higher EIH. METHODS: In this cross-sectional study, 37 pain-free participants (16 male, age 27.75 ± 9.91) completed a stop-signal task assessing cognitive inhibition ability and a control condition in the first session. In the second session, pre-post-test design EIH was assessed by means of aerobic bicycling (15 min., 75% VO2max) and isometric knee extension (90 sec, 30% MVC). EIH was assessed with pressure pain thresholds (PPT) and temporal summation of pain (TSP), each at the hand and at the leg. Correlational analyses quantified the associations between cognitive inhibition and EIH change scores. RESULTS: Better cognitive inhibition correlated with EIH change scores in PPTs after aerobic bicycling at the hand (r = -0.35, 95% CI: -0.57; -0.08, p =0.021), but not at the leg (rho = -0.10, 95% CI: -0.36; 0.18, p = 0.277). No correlations between cognitive inhibition and change in PPTs after isometric knee extension at the hand (rho = -0.03, 95% CI: -0.30; 0.25, p = 0.857) nor at the leg (rho = -0.03, 95% CI: -0.25; 0.30, p = 0.857) were observed. There were no EIH effects after isometric exercise and, generally, no effects of exercise on TSP. CONCLUSION: This study provides preliminary evidence for the notion that cognitive inhibition might play a supportive role in EIH. Although these results are clearly in need of replication, they accord well with previously reported associations between cognitive inhibition, experimental pain and descending pain inhibition.

Brain structural alterations associated with dysfunctional cognitive control of pain in patients with low back pain.

BACKGROUND: Recent evidence has shown that chronic back pain (CBP) can lead to functional alterations in the circuitry underlying the cognitive control of pain. Thought suppression (TS) is a common type of cognitive control of pain. Previous research has shown that TS has paradoxical effects that may increase the awareness of pain. Pain-related TS may also increase individuals' attention to pain, which may also increase pain sensation, but thus far, the relationship between pain-related TS and structural brain alterations is unknown. METHODS: In this study, we investigated a group of 30 patients 6 months after lumbar disc surgery by applying voxel-based morphometry (VBM) to identify brain regions correlated with TS scores. RESULTS: Since pain-related TS has been positively correlated with depression, all calculations were controlled for depression and age. VBM revealed a negative correlation between the TS score and regional grey matter volume (GMV) in the left superior temporal gyrus (LSTG) and the left middle temporal gyrus (L MTG), which is part of the left temporoparietal junction (L TPJ). In addition, a mediation analysis revealed a significant mediation effect of the pain-related TS on the association between GMV of the left TPJ and reported pain intensity in the last 7 days. CONCLUSIONS: These findings are consistent with previous research on the dysfunctional cognitive control of pain and may therefore provide potential insights into the neural substrates of obstructive cognitive control in chronic low back pain, with a special emphasis on pain-related TS. SIGNIFICANCE: The link between pain-related thought suppression and brain morphology may provide a new perspective on the understanding of cognitive control of pain in chronic low back pain, which may help improve cognitive behavioural therapy.

[Emotion regulation and pain : Behavioral and neuronal correlates: a transdiagnostic approach]. / Emotionsregulation und Schmerzen : Behaviorale und neuronale Korrelate ­ ein transdiagnostischer Ansatz.

Emotions and emotion regulation are of special importance in the perception and modulation of pain but the mechanisms underlying this reciprocal relationship remain unclear. The transdiagnostic model provides an approach to explain the link between pain and emotion regarding cognitive and neuronal mechanisms and aims to identify mutual processes, which are relevant for both. Structural and functional imaging studies of pain indicate the involvement of specific cortical and subcortical structures, which also play an important role in emotion regulation. While numerous studies have investigated emotion regulation and their correlates in the central nervous system in pathological states, the research on emotion regulation in pain is still young. The purpose of this review is to provide an overview of experimental and clinical studies of neuronal and behavioral correlates of pain-related emotion regulation. The current transdiagnostic approach may be able to enhance pain relief in the future.