Association between temporal summation and conditioned pain modulation in chronic low back pain: baseline results from 2 clinical trials

Abstract

Introduction: Temporal summation (TS) and conditioned pain modulation (CPM) represent different aspects of central pain processing. Their relationship and differential performance within distinct body locations are not well understood. Objectives: To examine the association between TS and CPM in chronic low back pain and the influence of testing location on this relationship. Methods: We analyzed baseline data from 2 clinical trials on participants with chronic low back pain (n 5 264; 47.3% female; mean age 5 41 years, SD 5 12; mean pain 5 5.3/10, SD 5 1.4). Measures used included questionnaires assessing pain and negative affect, phasic thermal TS at the hand (thenar) and the lower back (lumbar), followed by CPM that included a thermal testing stimulus (Heat-6, the temperature where pain rating is 6/10) and a cold-pressor conditioning stimulus. Nonparametric, proportional odds logistic regression was used to model thenar, and separately, lumbar TS, using CPM, Heat-6, negative affect, and demographics. Results: Our models revealed a small association (bs 5 0.17, P 5 0.01) between reduced CPM and heightened TS at both testing sites, regardless of demographics or negative affect. Conclusion: Results suggest a modest association between TS and CPM, irrespective of anatomical testing location, demographics, and negative affect. These findings will help improve the methodology and interpretation of TS and CPM measurement in clinical pain populations.

Exploration of Somatosensory Function of Patients With Acute Nonspecific Neck Pain, Through Quantitative Sensory Testing and Self-reported Symptoms

“…37 Dysfunctional CPM is previously identified in chronic NNP 10 and chronic pain in general. 38 The presence of increased TS and impaired CPM, which are commonly associated, 39 is highly suggestive of altered central pain processing early in NNP. Recent research has identified correlations between PPT and TS in chronic widespread musculoskeletal pain.…”

Effects of a multidimensional approach based on exercise and mindfulness on pain, disability, quality of life, mental health, and gait parameters in patients with non-specific chronic low back pain: the BACKFIT randomized controlled trial.

“…Two measurements will be conducted twice bilaterally. Each measure will be assessed in the middle side between L1-L5, 5 cm apart from the lumbar spinal processes [7,[42][43][44].…”

“…It is a 20-item self-administered questionnaire which patients are asked to indicate the score from 0 to 3 that best indicates how they feel at the time they are lling in the questionnaire. The range of score is 20-80: no anxiety (≤ 20), mild (21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39), moderate (40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59), and severe anxiety (60-80).…”

Harnessing the power of endogenous pain control mechanisms for novel therapeutics: how might innovations in neuroimaging help?

“…CPM is suggested to test the integrity of DNIC mechanisms only, so is unlikely to be informative of alterations in other descending control systems, such as those involved in stress-induced analgesia [11 ▪▪ ]. Other psychophysical tests, including quantitative sensory testing (QST) offset analgesia or temporal summation of pain [18][19][20][21] offer varying levels of sensitivity to detect pathology in different pain phenotypes, but they are similarly unlikely to be sufficient in isolation, nor are they expressly intended to probe descending control mechanisms. Multimodal convergent operations approaches to understanding complex behaviour are not new [22] and recent reports indicate their potential in pain research.…”