Gray matter alteration associated with pain catastrophizing in patients 6 months after lumbar disk surgery: a voxel-based morphometry study

Abstract. Introduction:. Pain catastrophizing (PC), the increased attention to harmful aspects of pain (magnification), and the belief of low controllability (helplessness) has been shown to be important in the maintenance of pain. A growing research on structural alterations in chronic pain revealed an association between PC and brain areas that are involved in affective and cognitive pain processing. However, little is known about a differential effect of the components magnification and helplessness. Objective:. The aim of this study was to identify brain regions associated with overall PC and with the single components of magnification and helplessness. Methods:. We investigated 29 patients 6 months after lumbar disk surgery using voxel-based morphometry. Magnification and helplessness were assessed with subscales of the Avoidance-Endurance Questionnaire (AEQ); overall PC was computed using the sum score. The structural brain imaging data were preprocessed and analyzed using SPM8 and VBM8. Multiple regression analyses were performed with PC scales as predictors and depression as covariate. Results:. Pain catastrophizing was significantly associated with cortical gray matter in brain areas involved in processing attentional, sensory, and affective aspects of pain, including the left posterior cingulate cortex, supplementary motor area, and medial frontal gyrus. In addition, we provide preliminary evidence for brain structure association related to magnification and helplessness. Conclusion:. This study provides evidence for PC-related structural alterations in patients with low back pain, which are consistent with findings from previous research in different chronic pain disorders. This study is the first to evaluate brain changes related to differential domains of PC

Depression and suicidal ideation in high‐performance athletes suffering from low back pain: the role of stress and pain‐related thought suppression

Depression and suicidal ideation are important health problems in athletes suffering from pain. Dysfunctional pain cognitions, that is, pain-related thought suppression (PTS), may play an important role in their aetiology. Thought suppression was shown to increase depressive mood, particularly in highly stressed individuals. This cross-sectional study examines the relationship between PTS and stress on depression and suicidal ideation in athletes with pain.A total of 159 athletes with non-specific low back pain completed a set of questionnaires to measure PTS, depression and stress. Participants were split into groups with high and low stress, and high and low PTS. Two-way ANOVA calculated main effects for PTS, stress and a PTS*stress interaction, with depressive symptoms as dependent. Subsequently, distribution tests were calculated, investigating if the presence of clinically relevant depression and suicidal ideation is dependent of conditions of high/low PTS and stress.A main effect of stress demonstrated higher depression scores in highly stressed athletes. Further, a significant PTS*stress interaction showed elevated depression scores in athletes with high PTS and high stress. Distribution analysis revealed positive associations between PTS, stress and depression, with depression being most frequent among athletes with high PTS and high stress. Suicidal ideation was not significantly associated with PTS and only weakly correlated with stress.Our findings show that PTS is the most common pain response in athletes with pain. The results indicate a higher prevalence of depression and elevated depressive symptoms in athletes experiencing high stress, seemingly more pronounced when highly engaging in PTS.This study contributes to the understanding of depression in athletes with pain, suggesting stress and pain-related thought suppression to increase symptoms and prevalence of depression. As athletes often experience acute or chronic pain, understanding the impact of pain cognitions on health outcomes is an important step in the optimization of treatments

Cognitive inhibition correlates with exercise-induced hypoalgesia after aerobic bicycling in pain-free participants

$\bf Purpose:$ 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. $\bf Methods:$ In this cross-sectional study, 37 pain-free participants (16 male, age 27.75 $\pm$ 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% VO$_2$2max) 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. $\bf Results:$ Better cognitive inhibition correlated with EIH change scores in PPTs after aerobic bicycling at the hand ($\it r$ = − 0.35, 95% CI: − 0.57; − 0.08, ($\it p$ = 0.021), but not at the leg (rho = − 0.10, 95% CI: − 0.36; 0.18, ($\it p$ = 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, ($\it p$ = 0.857) nor at the leg (rho = − 0.03, 95% CI: − 0.25; 0.30, ($\it p$ = 0.857) were observed. There were no EIH effects after isometric exercise and, generally, no effects of exercise on TSP. $\bf Conclusion:$ 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