scholarly journals Does Acetaminophen Activate Endogenous Pain Inhibition in Chronic Fatigue Syndrome/ Fibromyalgia and Rheumatoid Arthritis? A DoubleBlind Randomized Controlled Cross-over Trial

2013 ◽  
Vol 2;16 (2;3) ◽  
pp. E61-E70 ◽  
Author(s):  
Mira Meeus
Keyword(s):  
Temporal Summation ◽  
Chronic Fatigue ◽  
Pain Modulation ◽  
Conditioned Pain Modulation ◽  
Pain Processing ◽  
Central Pain ◽  
Healthy Controls ◽  
Fatigue Syndrome ◽  
Central Pain Processing ◽  
Pain Inhibition

Background: Although enhanced temporal summation (TS) and conditioned pain modulation (CPM), as characteristic for central sensitization, has been proved to be impaired in different chronic pain populations, the exact nature is still unknown. Objectives: We examined differences in TS and CPM in 2 chronic pain populations, patients with both chronic fatigue syndrome (CFS) and comorbid fibromyalgia (FM) and patients with rheumatoid arthritis (RA), and in sedentary, healthy controls, and evaluated whether activation of serotonergic descending pathways by acetaminophen improves central pain processing. Study Design: Double-blind randomized controlled trial with cross-over design. Methods: Fifty-three women (19 CFS/FM patients, 16 RA patients, and 18 healthy women) were randomly allocated to the experimental group (1 g acetaminophen) or the placebo group (1 g dextrose). Participants underwent an assessment of endogenous pain inhibition, consisting of an evaluation of temporal summation with and without conditioned pain modulation (CPM). Seven days later groups were crossed-over. Patients and assessors were blinded for the allocation. Results: After intake of acetaminophen, pain thresholds increased slightly in CFS/FM patients, and decreased in the RA and the control group. Temporal summation was reduced in the 3 groups and CPM at the shoulder was better overall, however only statistically significant for the RA group. Healthy controls showed improved CPM for both finger and shoulder after acetaminophen, although not significant. Limitations: The influence of acetaminophen on pain processing is inconsistent, especially in the patient groups examined. Conclusion: This is the first study comparing the influence of acetaminophen on central pain processing in healthy controls and patients with CFS/FM and RA. It seems that CFS/ FM patients present more central pain processing abnormalities than RA patients, and that acetaminophen may have a limited positive effect on central pain inhibition, but other contributors have to be identified and evaluated. Key words: Chronic pain, sensitization, acetaminophen, conditioned pain modulation, temporal summation, chronic fatigue syndrome, fibromyalgia, rheumatoid arthritis

The effect of one dry needling session on pain, central pain processing, muscle co-contraction and gait characteristics in patients with knee osteoarthritis: a randomized controlled trial

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sophie Vervullens ◽  
Lotte Meert ◽  
Isabel Baert ◽  
Nicolas Delrue ◽  
Christiaan H. W. Heusdens ◽  
...  
Keyword(s):  
Knee Osteoarthritis ◽  
Controlled Trial ◽  
Pain Modulation ◽  
Group Differences ◽  
Conditioned Pain Modulation ◽  
Pain Processing ◽  
Central Pain ◽  
Dry Needling ◽  
Spatiotemporal Parameters ◽  
Central Pain Processing

Abstract Objectives To assess the immediate and three days postintervention effect of one dry needling session compared to one sham needling session on pain, central pain processing, muscle co-contraction and spatiotemporal parameters during gait in knee osteoarthritis patients. Methods A double-blind randomized controlled trial was conducted. Sixty-one knee osteoarthritis patients were randomly assigned to the dry needling or sham needling group. Primary outcomes were pain and central pain processing. Secondary outcomes included muscle co-contraction and spatiotemporal parameters during gait. Patients were assessed at baseline and 15 min after the intervention, and pain also three days after the intervention. Linear mixed models were used to examine between- and within-group differences. Results No significant between-group differences for pain were found, but within-group scores showed a significant decrease 15 min after sham needling and three days after dry needling. The mean conditioned pain modulation effect measured at the m. Trapezius worsened significantly 15 min after sham needling compared to after dry needling (between-group difference). However, individual conditioned pain modulation percentage scores remained stable over time. Various significant within-group differences were found 15 min after sham needling: a decrease of conditioned pain modulation measured at m. Quadriceps and m. Trapezius and stride- and step-time scores, and an increase in step length and widespread pain pressure threshold. A significant decrease in muscle co-contraction index of the m. Vastus Medialis and Semitendinosus was found as within-group difference 15 min after dry needling. Conclusions Dry needling has no larger effect on pain, central pain processing, muscle co-contraction and gait pattern 15 min and three days postintervention compared to sham needling. Mean conditioned pain modulation scores worsened after sham needling compared to after dry needling. Further research remains necessary.

scholarly journals Central inhibition of pain is augmented in women with self-injurious behavior

2021 ◽  
Author(s):  
Maria Lalouni ◽  
Jens Fust ◽  
Johan Bjureberg ◽  
Granit Kastrati ◽  
Robin Fondberg ◽  
...  
Keyword(s):  
Temporal Summation ◽  
Pain Modulation ◽  
Pain Tolerance ◽  
Conditioned Pain Modulation ◽  
Heat Pain ◽  
Healthy Controls ◽  
Down Regulation ◽  
Pain Thresholds ◽  
Pressure Pain ◽  
Pressure Pain Thresholds

Individuals who engage in nonsuicidal self-injury (NSSI) have demonstrated higher pain thresholds and tolerance compared with individuals without NSSI. The objective of the study was to assess which aspects of the pain regulatory system that account for this augmented pain perception. In a cross-sectional design, 81 women, aged 18-35 (mean [SD] age, 23.4 [3.9]), were included (41 with NSSI and 40 healthy controls). A quantitative sensory testing protocol, including heat pain thresholds, heat pain tolerance, pressure pain thresholds, conditioned pain modulation (assessing central down-regulation of pain), and temporal summation (assessing facilitation of pain signals) was used. Thermal pain stimuli were assessed during fMRI scanning and NSSI behaviors and clinical symptoms were self-assessed. NSSI participants demonstrated higher pain thresholds during heat and pressure pain compared to controls. During conditioned pain modulation, NSSI participants showed a more effective central down-regulation of pain for NSSI participants. Temporal summation did not differ between the groups. There were no correlations between pain outcomes and NSSI behaviors or clinical characteristics. The fMRI analyses revealed increased activity in the primary and secondary somatosensory cortex in NSSI participants, compared to healthy controls, which are brain regions implicated in sensory aspects of pain processing. The findings suggest segregated inhibitory mechanisms for pain and emotion in NSSI, as pain insensitivity was linked to enhanced inhibitory control of pain in spite of significant impairments in emotion regulation. This may represent an endophenotype associated with a greater risk for developing self-injurious behavior.

scholarly journals Cerebral Blood Flow and Heart Rate Variability in Chronic Fatigue Syndrome: A Randomized Cross-Over Study

2018 ◽  
Vol 1 (21;1) ◽  
pp. E13-E24 ◽  
Author(s):  
Anneleen Malfliet
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Heart Rate Variability ◽  
Physical Exercise ◽  
Temporal Summation ◽  
Chronic Fatigue ◽  
Pain Modulation ◽  
Control Group ◽  
P Values ◽  
Fatigue Syndrome

Background: Pain, fatigue, and concentration difficulties are typical features of chronic fatigue syndrome (CFS). The exact underlying mechanisms of these symptoms are still unknown, but available evidence suggests an important role for impaired pain modulation. As evidence also suggests that pain modulation is related to cardiovascular mechanisms, it seems logical to investigate whether cerebral blood flow (CBF) and heart rate variability (HRV) are altered in these patients. Objectives: We aimed to investigate the role of the cardiovascular system in pain modulation and symptoms of CFS; the response of CBF and HRV to physical stress and their relation to the change in temporal summation (TS) of pressure pain and selfreported symptoms was evaluated. Study Design: A controlled, randomized cross-over trial. Setting: University Hospital Brussels. Methods: Twenty CFS patients and 20 sedentary healthy controls were included in this study. In both of the groups, the change in TS of pressure pain, CBF (using transcranial Doppler), and HRV (using finger plethysmography) was examined during physical and emotional stress (to control for potential bias), as well as their association mutually and with self-reported symptoms of pain, fatigue, and concentrations difficulties. Results: There was no significant interaction or group (F-values ranging from .100 to 1.862, P-values ranging from .754 to .181) effect in CBF or HRV parameters. HRV and CBF did change during physical exercise, but the changes did not differ between patients and controls. While pain scores during TS at the trapezius site reduced in the control group after the physical exercise protocol (P = .037), they did not change in the CFS group (P = .108), suggesting impaired pain modulation. There were no significant correlations between CBF, HRV, TS, and self-reported symptoms (all P-values of correlation analyses > .01). Limitations: Although effect sizes were medium to large, the study sample was relatively low. Also, the mild nature of the exercise bout is discussable. Nonetheless, this mild exercise was able to provoke endogenous pain modulation in the control group, which endorsed a proper execution of the cycling exercise. Moreover, mild exercises are more applicable to daily physical activities in CFS patients than vigorous exercises. Conclusion: These results seem to refute the previously suggested alterations of CBF/ HRV in CFS patients. These cardiovascular parameters appear not to explain pain before, during, and following exercise. Key words: Chronic pain, physical exercise, emotional stress, pain modulation, cardiovascular systems, temporal summation, pain pressure thresholds, transcranial Doppler, plethysmography

The inhibitory effect of conditioned pain modulation on temporal summation in low-back pain patients

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Søren O’Neill ◽  
Liam Holm ◽  
Johanne Brinch Filtenborg ◽  
Lars Arendt-Nielsen ◽  
Casper Glissmann Nim
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Test Stimulus ◽  
Temporal Summation ◽  
Pain Modulation ◽  
Conditioned Pain Modulation ◽  
Low Back ◽  
Pressure Pain ◽  
Pain Patients ◽  
Pain Inhibition

Abstract Objectives The literature on conditioned pain modulation (CPM) is inconclusive in relation to low-back pain and it is unclear how CPM affects temporal summation as a proxy of central pain integration. The aim of this study was to examine whether the CPM effect would be different on pain induced by temporal summation than single stimuli in a group of low back pain patients. Methods A total of 149 low-back pain patients were included. CPM was examined using single, repeated and temporal summation (repeated-single difference) of mechanical pressure pain as test stimuli at an individualized, fixed supra-pain-threshold force, before and after 2 min of cold pressor test (0–2 degrees Celsius). Participants were categorized as CPM responders or non-responders according to three different criteria: simple (any pain inhibition), strict (pain inhibition of more than 10VAS) and reversed (pain inhibition or facilitation of less than 10VAS). Clinical data on back pain was collected for correlation and descriptive purposes. Results Significant modulation was observed for all three test stimuli. Effects sizes were comparable in relative terms, but repeated pressure pain modulation was greater in absolute terms. No correlations to clinical data were observed, for any measure. Conclusions The current data suggests that repeated pressure pain may be better suited as the CPM test stimuli, than single pressure pain and temporal summation of pressure pain, as the CPM effect in absolute terms was greater. Employing temporal summation as the test stimulus in a CPM paradigm may be more sensitive than a single test stimulus.

The development of a novel questionnaire assessing alterations in central pain processing in people with and without chronic pain

2020 ◽  
Vol 20 (2) ◽  
pp. 407-417
Author(s):  
Philip D. Austin ◽  
Ali Asghari ◽  
Daniel S.J. Costa ◽  
Philip J. Siddall
Keyword(s):  
Chronic Pain ◽  
Factor Analysis ◽  
Exploratory Factor Analysis ◽  
Pain Modulation ◽  
Self Report ◽  
Pain Processing ◽  
Central Pain ◽  
Item Questionnaire ◽  
Excellent Internal Consistency ◽  
Central Pain Processing

AbstractBackground and aimsThe purpose of this study was to (a) develop and (b) conduct exploratory factor analysis on a novel self-report instrument for symptoms associated with altered central pain processing.MethodsWe first developed a 25-item questionnaire based on previous literature identifying symptoms and behaviours that may reflect altered spinal and supraspinal pain processing. We then administered this questionnaire to 183 people with chronic pain (n = 99) and healthy individuals (n = 84). Exploratory factor analysis was conducted to identify the factor structure of the questionnaire.ResultsOur results support a two-factor solution for the 25-item questionnaire that accounted for 57.2% of the total variance of responses in people with and without chronic pain. Factor one (11 items) included items related to alterations in sensation of pain, while factor two (seven items) included items associated with emotional and fatigue symptoms. Seven items showed weak factor loadings and were eliminated. Reliability was excellent, while both factors showed strong correlations with previously-validated self-report Instruments: (pain catastrophising, mood, vigilance, pain self-efficacy) and conditioned pain modulation, providing evidence for their validity.ConclusionsWe have developed a questionnaire containing two factors that appear to be related to two different symptom clusters, one of which is specifically related to pain and one of which contains other health-related symptoms related to mood and fatigue. These factors show excellent internal consistency and validity. This questionnaire may be a quick, easy and reliable instrument to assess central pain processing in clinical settings.

Differential central pain processing following repetitive intramuscular proton/prostaglandin E2 injections in female fibromyalgia patients and healthy controls

2011 ◽  
Vol 15 (7) ◽  
pp. 716-723 ◽  
Author(s):  
Martin Diersl ◽  
Marcus T. Schleyl ◽  
Mariela Rancel ◽  
Pinar Yilmazl ◽  
Lydia Lauerl ◽  
...  
Keyword(s):  
Prostaglandin E2 ◽  
Pain Processing ◽  
Central Pain ◽  
Healthy Controls ◽  
Central Pain Processing

scholarly journals Endogenous Pain Facilitation Rather Than Inhibition Differs Between People with Chronic Fatigue Syndrome, Multiple Sclerosis, and Controls: An Observational Study

2017 ◽  
Vol 4 (20;4) ◽  
pp. E489-E497
Author(s):  
Kelly Ickman
Keyword(s):  
Multiple Sclerosis ◽  
Chronic Fatigue Syndrome ◽  
Central Sensitization ◽  
Temporal Summation ◽  
Cuff Pressure ◽  
Experimental Pain ◽  
Chronic Fatigue ◽  
Pain Modulation ◽  
Fatigue Syndrome ◽  
Pressure Threshold

Background: Commonalities in the core symptoms of fatigue and cognitive dysfunction experienced by chronic fatigue syndrome (CFS, also known as ME) and multiple sclerosis (MS) patients have been described. Many CFS and MS patients also experience chronic pain, which has been attributed to central sensitization in both groups of patients. However, the characteristics of pain in CFS and MS patients have not been compared. Objectives: To compare experimental pain measurements in patients with CFS or MS and healthy controls. Study design: Observational study. Setting: This study took place in Belgium at Vrije Universiteit Brussel and the University of Antwerp. Methods: Pressure pain thresholds, temporal summation, conditioned pain modulation, and occlusion cuff pressure thresholds rated as painful (1st cuff pressure threshold) and as 3/10 on a verbal numerical scale (2nd cuff pressure threshold) were measured in patients with CFS (n = 48), MS (n = 19) and healthy pain-free controls (n = 30). Adjusted between-group differences were estimated using linear regression models. Results: Finger pain pressure thresholds of patients with CFS, compared with patients with MS, were 25% lower (difference ratio 0.75 [95% CI 0.59, 0.95], P = 0.02) and shoulder pain pressure thresholds were 26% lower (difference ratio 0.74 [0.52, 1.04], P = 0.08). Compared with patients with MS, patients with CFS had 29% lower first cuff pressure threshold (difference ratio 0.71 [0.53, 0.94], P = 0.02) and 41% lower 2nd cuff pressure threshold (0.59 [0.41, 0.86], P = 0.006). Finger temporal summation was higher in patients with CFS than in patients with MS (mean difference 1.15 [0.33, 1.97], P = 0.006), but there were no differences in shoulder temporal summation or conditioned pain modulation at either site. Differences between patients with CFS and MS tended to be greater than between either patient group and healthy controls. Pain pressure thresholds and cuff pressure thresholds tended to be positively correlated, and temporal summation negatively correlated, with higher physical function and lower fatigue in both groups of patients. Subjective pain in patients with CFS but not in patients with MS was strongly negatively correlated with pain pressure thresholds and cuff pressure thresholds, and positively correlated with temporal summation. Limitations: The main limitations of our study are the relatively small sample sizes, its crosssectional design, and its exploratory nature. Conclusions: We found differences in the characteristics of pain symptoms reported by patients with CFS and patients with MS, which suggest different underlying mechanisms. Specifically, overactive endogenous pain facilitation was characteristic of pain in patients with CFS but not in patients with MS, suggesting a greater role for central sensitization in CFS. Keywords: Chronic fatigue syndrome, CFS/ME, multiple sclerosis, experimental pain, central sensitization

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