Dynamic Quantitative Sensory Testing to Characterize Central Pain Processing

Abstract

Central facilitation and modulation of incoming nociceptive signals play an important role in the perception of pain. Disruption in central pain processing is present in many chronic pain conditions and can influence responses to specific therapies. Thus, the ability to precisely describe the state of central pain processing has profound clinical significance in both prognosis and prediction. Because it is not practical to record neuronal firings directly in the human spinal cord, surrogate behavior tests become an important tool to assess the state of central pain processing. Dynamic QST is one such test, and can probe both the ascending facilitation and descending modulation of incoming nociceptive signals via TS and CPM, respectively. Due to the large between-individual variability in the sensitivity to noxious signals, standardized TS and CPM tests may not yield any meaningful data in up to 50% of the population due to floor or ceiling effects. We present methodologies to individualize TS and CPM so we can capture these measures in a broader range of individuals than previously possible. We have used these methods successfully in several studies at the lab, and data from one ongoing study will be presented to demonstrate feasibility and potential applications of the methods.

Effect of Electroacupuncture vs Sham Treatment on Change in Pain Severity Among Adults With Chronic Low Back Pain

“…The 14 prespecified potential factors associated with response with details of their measurement 24 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 are presented in Table 1 . Both PROMIS pain and RMDQ scores were collected at the pretreatment and posttreatment visits, approximately 2 weeks before the first treatment session and 2 weeks after the last treatment session.…”

<p>Multisensory Sensitivity is Related to Deep-Tissue but Not Cutaneous Pain Sensitivity in Healthy Individuals</p>

“…For example, prior studies report mixed findings on the relationships between thermal pain sensitivity and non-noxious sensory sensitivity. 11,13,21 However, if MSS is related to chronic pain due to underlying shared central mechanisms as previously suggested, 11,12,14 then one might expect MSS to be more closely related to dynamic QST and referred pain, both associated with central mechanisms, [5][6][7]22 than to static QST or local pain. Unfortunately, studies are lacking that consider multiple QST modalities (eg, thermal and mechanical) using both static (thresholds) and dynamic (temporal summation or conditioned pain modulation) assessments or controlled experimentally induced pain models.…”

“…4,5 Because central mechanisms and nociplastic changes cannot be assessed directly in humans, they are typically inferred as greater pain sensitivity using dynamic quantitative sensory testing (QST) relative to healthy individuals. [4][5][6][7][8] More specifically, dynamic QST includes assessment of temporal summation of pain (TSP) and conditioned pain modulation (CPM). TSP refers to a wind-up response of C fibers to repetitive activation in animal models 9 and has been well accepted as a psychophysical measure of net central facilitation of human pain in clinical settings.…”

“…TSP refers to a wind-up response of C fibers to repetitive activation in animal models 9 and has been well accepted as a psychophysical measure of net central facilitation of human pain in clinical settings. 6,7 Similarly, CPM, which is psychophysically associated with diffuse noxious inhibitory controls, 10 has been widely accepted as a measure of net endogenous descending inhibition of human pain in practice. 6,7 Emerging evidence suggests multisensory sensitivity (MSS) could potentially serve as an additional marker to reflect the status of CNS sensitivity as elevated MSS has been theorized to be attributable to a sensitized CNS.…”

“…6,7 Similarly, CPM, which is psychophysically associated with diffuse noxious inhibitory controls, 10 has been widely accepted as a measure of net endogenous descending inhibition of human pain in practice. 6,7 Emerging evidence suggests multisensory sensitivity (MSS) could potentially serve as an additional marker to reflect the status of CNS sensitivity as elevated MSS has been theorized to be attributable to a sensitized CNS. [11][12][13][14] Indeed, a review showed pre-morbid assessments of high sensory sensitivity using QST were predictors of central sensitization.…”