F126 RELIABILITY OF “CONDITIONED PAIN MODULATION” TESTING USING SUBJECTIVE PAIN INTENSITY AND THE NOCICEPTIVE FLEXION REFLEX AMPLITUDE

Abstract Background Conditioned pain modulation (CPM) evaluates the effect of a painful conditioning stimulus (CS) on a painful test stimulus (TS). Using painful cutaneous electrical stimulation (PCES) as TS and painful cold water as CS, the pain relief was paralleled by a decrease in evoked potentials (PCES-EPs). We now aimed to compare the effect of CPM with cognitive distraction on PCES-induced pain and PCES-EP amplitudes. Methods PCES was performed using surface electrodes inducing a painful sensation of 60 (NRS 0–100) on one hand. In a crossover design healthy subjects (included: n = 38, analyzed: n = 23) immersed the contralateral hand into 10 °C cold water (CS) for CPM evaluation and performed the 1-back task for cognitive distraction. Before and during the CS and 1-back task, respectively, subjects rated the pain intensity of PCES and simultaneously cortical evoked potentials were recorded. Results Both CPM and cognitive distraction significantly reduced PCES-EP amplitudes (CPM: 27.6 ± 12.0 μV to 20.2 ± 9.5 μV, cognitive distraction: 30.3 ± 14.2 µV to 13.6 ± 5.2 μV, p < 0.001) and PCES-induced pain (on a 0–100 numerical rating scale: CPM: 58 ± 4 to 41.1 ± 12.3, cognitive distraction: 58.3 ± 4.4 to 38.0 ± 13.0, p < 0.001), though the changes in pain intensity and PCES-amplitude did not correlate. The changes of the PCES-EP amplitudes during cognitive distraction were more pronounced than during CPM (p = 0.001). Conclusions CPM and cognitive distraction reduced the PCES-induced pain to a similar extent. The more pronounced decrease of PCES-EP amplitudes after distraction by a cognitive task implies that both conditions might not represent the general pain modulatory capacity of individuals, but may underlie different neuronal mechanisms with the final common pathway of perceived pain reduction.

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Not just a matter of pain intensity: Effects of three different conditioning stimuli on conditioned pain modulation effects

Neurophysiologie Clinique ◽

10.1016/j.neucli.2018.06.078 ◽

2018 ◽

Vol 48 (5) ◽

pp. 287-293 ◽

Cited By ~ 5

Author(s):

Valquíria Aparecida da Silva ◽

Ricardo Galhardoni ◽

Manoel Jacobsen Teixeira ◽

Daniel Ciampi de Andrade

Keyword(s):

Pain Intensity ◽

Pain Modulation ◽

Conditioned Pain Modulation ◽

Conditioning Stimuli

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Reliability of Subjective Pain Ratings and Nociceptive Flexion Reflex Responses as Measures of Conditioned Pain Modulation

Pain Research and Management ◽

10.1155/2014/698246 ◽

2014 ◽

Vol 19 (2) ◽

pp. 93-96 ◽

Cited By ~ 22

Author(s):

Carlo Jurth ◽

Benno Rehberg ◽

Falk von Dincklage

Keyword(s):

Intraclass Correlation ◽

Pain Modulation ◽

Hot Water ◽

Conditioned Pain Modulation ◽

Good Test ◽

Retest Reliability ◽

Reflex Responses ◽

Pain Ratings ◽

Subjective Pain ◽

Test Retest Reliability

BACKGROUND: The endogenous modulation of pain can be assessed through conditioned pain modulation (CPM), which can be quantified using subjective pain ratings or nociceptive flexion reflexes. However, to date, the test-retest reliability has only been investigated for subjective pain ratings.OBJECTIVE: To compare the test-retest reliability of CPM-induced changes, measured using subjective pain ratings and nociceptive flexion reflexes, to provide a reliable scoring parameter for future studies.METHOD: A total of 40 healthy volunteers each received painful electrical stimuli to the sural nerve to elicit nociceptive flexion reflexes. Reflex sizes and subjective pain ratings were recorded before and during the immersion of the contralateral hand in hot water to induce CPM as well as innocuous water as control. Measurements were repeated in a retest 28 days later.RESULTS: Intraclass correlation coefficients showed good test-retest reliabilities of CPM during the hot water stimulus for both scoring parameters. Subjective pain ratings also correlated between test and retest during the control stimulus.CONCLUSIONS: Subjective pain ratings and nociceptive flexion reflexes show comparable test-retest reliabilities, but they reflect different components of CPM. While subjective pain ratings appear to incorporate cognitive influences to a larger degree, reflex responses appear to reflect spinal nociception more purely.

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Distraction by a cognitive task has a higher impact on electrophysiological measures compared with conditioned pain modulation

10.21203/rs.3.rs-26882/v4 ◽

2020 ◽

Author(s):

A. T. Lisa Do ◽

Elena Enax-Krumova ◽

Özüm Özgül ◽

Lynn B. Eitner ◽

Stefanie Heba ◽

...

Keyword(s):

Evoked Potentials ◽

Pain Intensity ◽

Rating Scale ◽

Cold Water ◽

Cognitive Task ◽

Pain Modulation ◽

Conditioned Pain Modulation ◽

Cognitive Distraction ◽

Painful Sensation ◽

Back Task

Abstract BackgroundConditioned pain modulation (CPM) evaluates the effect of a painful conditioning stimulus (CS) on a painful test stimulus (TS). Using painful cutaneous electrical stimulation (PCES) as TS and painful cold water as CS, the pain relief was paralleled by a decrease in evoked potentials (PCES-EPs). We now aimed to compare the effect of CPM with cognitive distraction on PCES-induced pain and PCES-EP amplitudes. MethodsPCES was performed using surface electrodes inducing a painful sensation of 60 (NRS 0-100) on one hand. In a crossover design healthy subjects (included: n=38, analyzed: n=23) immersed the contralateral hand into 10°C cold water (CS) for CPM evaluation and performed the 1-back task for cognitive distraction. Before and during the CS and 1-back task, respectively, subjects rated the pain intensity of PCES and simultaneously cortical evoked potentials were recorded. ResultsBoth CPM and cognitive distraction significantly reduced PCES-EP amplitudes (CPM: 27.6±12.0μV to 20.2±9.5μV, cognitive distraction: 30.3±14.2µV to 13.6±5.2μV, p<0.001) and PCES-induced pain (on a 0–100 numerical rating scale: CPM: 58±4 to 41.1±12.3, cognitive distraction: 58.3±4.4 to 38.0±13.0, p<0.001), though the changes in pain intensity and PCES-amplitude did not correlate. The changes of the PCES-EP amplitudes during cognitive distraction were more pronounced than during CPM (p=0.001).ConclusionsCPM and cognitive distraction reduced the PCES-induced pain to a similar extent. The more pronounced decrease of PCES-EP amplitudes after distraction by a cognitive task implies that both conditions might not represent the general pain modulatory capacity of individuals, but may underlie different neuronal mechanisms with the final common pathway of perceived pain reduction.

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The Potential Clinical Utility of Pressure-Based vs. Heat-Based Paradigms to Measure Conditioned Pain Modulation in Healthy Individuals and Those With Chronic Pain

Frontiers in Pain Research ◽

10.3389/fpain.2021.784362 ◽

2021 ◽

Vol 2 ◽

Author(s):

Rima El-Sayed ◽

Camille Fauchon ◽

Junseok A. Kim ◽

Shahrzad Firouzian ◽

Natalie R. Osborne ◽

...

Keyword(s):

Chronic Pain ◽

Pain Intensity ◽

Pain Treatment ◽

Detection Threshold ◽

Conditioning Stimulus ◽

Pain Modulation ◽

Conditioned Pain Modulation ◽

Healthy Individuals ◽

Significant Difference ◽

Clinical Adoption

Conditioned pain modulation (CPM) is a physiological measure thought to reflect an individual's endogenous pain modulation system. CPM varies across individuals and provides insight into chronic pain pathophysiology. There is growing evidence that CPM may help predict individual pain treatment outcome. However, paradigm variabilities and practical issues have impeded widespread clinical adoption of CPM assessment. This study aimed to compare two CPM paradigms in people with chronic pain and healthy individuals. A total of 30 individuals (12 chronic pain, 18 healthy) underwent two CPM paradigms. The heat CPM paradigm acquired pain intensity ratings evoked by a test stimulus (TS) applied before and during the conditioning stimulus (CS). The pressure CPM paradigm acquired continuous pain intensity ratings of a gradually increasing TS, before and during CS. Pain intensity was rated from 0 (no pain) to 100 (worst pain imaginable); Pain50 is the stimulus level for a response rated 50. Heat and pressure CPM were calculated as a change in TS pain intensity ratings at Pain50, where negative CPM scores indicate pain inhibition. We also determined CPM in the pressure paradigm as change in pressure pain detection threshold (PDT). We found that in healthy individuals the CPM effect was significantly more inhibitory using the pressure paradigm than the heat paradigm. The pressure CPM effect was also significantly more inhibitory when based on changes at Pain50 than at PDT. However, in individuals with chronic pain there was no significant difference in pressure CPM compared to heat or PDT CPM. There was no significant correlation between clinical pain measures (painDETECT and Brief Pain Inventory) and paradigm type (heat vs. pressure), although heat-based CPM and painDETECT scores showed a trend. Importantly, the pressure paradigm could be administered in less time than the heat paradigm. Thus, our study indicates that in healthy individuals, interpretation of CPM findings should consider potential modality-dependent effects. However, in individuals with chronic pain, either heat or pressure paradigms can similarly be used to assess CPM. Given the practical advantages of the pressure paradigm (e.g., short test time, ease of use), we propose this approach to be well-suited for clinical adoption.

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Divergent effects of conditioned pain modulation on subjective pain and nociceptive-related brain activity

Experimental Brain Research ◽

10.1007/s00221-019-05545-8 ◽

2019 ◽

Vol 237 (7) ◽

pp. 1735-1744 ◽

Cited By ~ 2

Author(s):

Sergiu Albu ◽

Mary W. Meagher

Keyword(s):

Brain Activity ◽

Pain Modulation ◽

Conditioned Pain Modulation ◽

Subjective Pain

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