Determinants of endogenous analgesia magnitude in a diffuse noxious inhibitory control (DNIC) paradigm: Do conditioning stimulus painfulness, gender and personality variables matter? Pain

Faculty of Social Welfare and Health Studies, University of Haifa, Israel.
Pain (Impact Factor: 5.21). 06/2008; 136(1-2):142-9. DOI: 10.1016/j.pain.2007.06.029
Source: PubMed

ABSTRACT Descending modulation of pain can be demonstrated psychophysically by dual pain stimulation. This study evaluates in 31 healthy subjects the association between parameters of the conditioning stimulus, gender and personality, and the endogenous analgesia (EA) extent assessed by diffuse noxious inhibitory control (DNIC) paradigm. Contact heat pain was applied as the test stimulus to the non-dominant forearm, with stimulation temperature at a psychophysical intensity score of 60 on a 0-100 numerical pain scale. The conditioning stimulus was a 60s immersion of the dominant hand in cold (12, 15, 18 degrees C), hot (44 and 46.5 degrees C), or skin temperature (33 degrees C) water. The test stimulus was repeated on the non-dominant hand during the last 30s of the conditioning immersion. EA extent was calculated as the difference between pain scores of the two test stimuli. State and trait anxiety and pain catastrophizing scores were assessed prior to stimulation. EA was induced only for the pain-generating conditioning stimuli at 46.5 degrees C (p=0.011) and 12 degrees C (p=0.003). EA was independent of conditioning pain modality, or personality, but a significant gender effect was found, with greater EA response in males. Importantly, pain scores of the conditioning stimuli were not correlated with EA extent. The latter is based on both our study population, and on additional 82 patients, who participated in another study, in which EA was induced by immersion at 46.5 degrees C. DNIC testing, thus, seems to be relatively independent of the stimulation conditions, making it an easy to apply tool, suitable for wide range applications in pain psychophysics.

Download full-text


Available from: Michal Granot, Mar 04, 2015
16 Reads
    • "Several studies have shown positive relationships between CS pain intensity and CPM (van Wijk and Veldhuijzen, 2010), whilst others have been inconclusive (Pud et al., 2009). Granot et al. (2008) suggested a mild CS may evoke CPM, and it may be possible to elicit inhibitory effects on a TS using an innocuous CS (Treister et al., 2010). Lewis et al. (2012) found no difference in CPM effect size with greater CS pain intensity. "
    [Show abstract] [Hide abstract]
    ABSTRACT: People with chronic pain may exhibit pro-nociceptive phenotypes characterised partly by reduced conditioned pain modulation (CPM). Characterising variability in CPM in people with chronic low back pain (CLBP) may inform management. To investigate pro/anti-nociceptive effects of a CPM protocol in age/sex-matched healthy controls (HCs) and people with CLBP. Case-controlled trial (64 participants/group). The CPM protocol involved: test stimulus (TS) (noxious pressure applied by algometer to lumbar region); conditioning stimulus (CS) (noxious heat applied by thermode to dorsal hand). CPM recruitment was measured by the change in pain intensity (rated on a numeric rating scale (NRS)) of the TS in the presence and absence of the CS. Responses to this CPM protocol were variable for both groups with measures consistent with either inhibitory or facilitatory effects. A significantly greater proportion of facilitatory responses were seen in the CLBP cohort compared to HCs (73% versus 31%). In response to the CS, participants with CLBP demonstrated a mean increase in NRS scores (mean 1.3 points; p < 0.001), while HCs did not (mean -0.2 points; p = 0.35) and the between-group difference in change scores was significant (mean 1.4 points; p < 0.001; effect size (Hedges' g): 1.03). In HCs and participants with CLBP this CPM protocol elicited responses consistent with varying pro/anti-nociceptive effects. The higher proportion of participants with CLBP demonstrating a facilitatory response suggests a pro-nociceptive phenotype may characterise this cohort. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Manual therapy 03/2015; 101. DOI:10.1016/j.math.2015.02.011 · 1.71 Impact Factor
  • Source
    • "However, as argued by some authors, it could also be that less efficient CPM systems may enhance the intensity of a painful experience, which in turn could cause higher catastrophizing [28]. In line with other studies [27], [29], we found no association between CPM response and catastrophizing. This indicates that pain catastrophizing is an independent psychological predictor of increased acute postoperative pain. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Variability in patients' postoperative pain experience and response to treatment challenges effective pain management. Variability in pain reflects individual differences in inhibitory pain modulation and psychological sensitivity, which in turn may be clinically relevant for the disposition to acquire pain. The aim of this study was to investigate the effects of conditioned pain modulation and situational pain catastrophizing on postoperative pain and pain persistency. Preoperatively, 42 healthy males undergoing funnel chest surgery completed the Spielberger's State-Trait Anxiety Inventory and Beck's Depression Inventory before undergoing a sequential conditioned pain modulation paradigm. Subsequently, the Pain Catastrophizing Scale was introduced and patients were instructed to reference the conditioning pain while answering. Ratings of movement-evoked pain and consumption of morphine equivalents were obtained during postoperative days 2-5. Pain was reevaluated at six months postoperatively. Patients reporting persistent pain at six months follow-up (n = 15) were not significantly different from pain-free patients (n = 16) concerning preoperative conditioned pain modulation response (Z = 1.0, P = 0.3) or level of catastrophizing (Z = 0.4, P = 1.0). In the acute postoperative phase, situational pain catastrophizing predicted movement-evoked pain, independently of anxiety and depression (β = 1.0, P = 0.007) whereas conditioned pain modulation predicted morphine consumption (β = -0.005, P = 0.001). Preoperative conditioned pain modulation and situational pain catastrophizing were not associated with the development of persistent postoperative pain following funnel chest repair. Secondary outcome analyses indicated that conditioned pain modulation predicted morphine consumption and situational pain catastrophizing predicted movement-evoked pain intensity in the acute postoperative phase. These findings may have important implications for developing strategies to treat or prevent acute postoperative pain in selected patients. Pain may be predicted and the malfunctioning pain inhibition mechanism as tested with CPM may be treated with suitable drugs augmenting descending inhibition.
    PLoS ONE 02/2014; 9(2):e90185. DOI:10.1371/journal.pone.0090185 · 3.23 Impact Factor
  • Source
    • "conditioning stimulus seems to be more critical (Lautenbacher et al. 2002; Granot et al. 2008). Accordingly, intense and summating conditioning stimuli such as hand immersion in hot or cold water have appeared to be very effective (Lewis et al. 2012). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Unlabelled: Abstract Background: Chemo-somatosensory evoked potentials (CSSEPs) elicited by chemical stimulation (CO₂ gas) of the nasal mucosa have been shown to be sensitive enough to pick up even weak analgesic effects. With the present study we wanted to investigate whether CSSEPs are also a sensitive tool to capture endogenous pain inhibitory mechanisms elicited by conditioned pain modulation (CPM; where a first conditioning stimulus reduces the sensitivity for a second test stimulus) with a conditioning stimulus of rather low noxious load. Methods: Seventeen healthy participants were tested for CPM effects (conditioning stimulus: tonic heat pain with intensities around the pain threshold induced via a thermode; test stimulus: chemonasal stimulation (73% and 78% CO₂)) on CSSEPs and on self-report ratings. Results: We found significant CPM effects in the CSSEPS, with reduced amplitudes and prolonged latencies at several electroencephalogram (EEG) recording positions when using the lower CO₂ concentration (73% CO₂). In contrast to the visible inhibitory effects on the CSSEPs, subjective ratings of the test stimulus did not reflect CPM action. Discussion: The experimental pain model using CO₂ stimuli to elicit CSSEPs proved to be sensitive enough to capture weak CPM effects elicited by a conditioning stimulus of rather low noxious load. The usage of such mild noxious conditioning stimuli-in contrast to stimuli of higher noxious load (e.g., cold pressor test)-has the advantage that the activation of other types of pain inhibitory mechanisms in parallel (like attentional distraction, stress-induced analgesia) can be avoided.
    Somatosensory & Motor Research 02/2014; 31(2). DOI:10.3109/08990220.2014.887562 · 0.64 Impact Factor
Show more