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Rouhi S, Egorova-Brumley N, Jordan AS. Chronic sleep deficiency and its impact on pain perception in healthy females. J Sleep Res 2024:e14284. [PMID: 38972675 DOI: 10.1111/jsr.14284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 06/19/2024] [Accepted: 06/25/2024] [Indexed: 07/09/2024]
Abstract
Acute sleep deprivation in experimental studies has been shown to induce pain hypersensitivity in females. However, the impact of natural sleep deficiency and fluctuations across the week on pain perception remains unclear. A sleep-monitoring headband and self-reports were utilized to assess objective and subjective sleep in longer (> 6 hr) and short sleepers (< 6 hr). Pain sensitivity measures including heat, cold, pressure pain thresholds, pain inhibition (conditioned pain modulation) and facilitation (tonic pain summation) were assessed on Mondays and Fridays. Forty-one healthy young (23.9 ± 0.74 years) women participated. Short sleepers slept on average 2 hr less than longer sleepers (297.9 ± 8.2 min versus 418.5 ± 10.9 min) and experienced impaired pain inhibitory response (mean = -21.14 ± 7.9°C versus mean = 15.39 ± 9.5°C; p = 0.005). However, no effect was observed in pain thresholds and pain summation (p > 0.05). Furthermore, pain modulatory responses differed between Mondays and Fridays. Chronic sleep deficiency (< 6 hr) compromises pain responses, notably on Mondays. Maintaining a consistent sleep pattern with sufficient sleep (> 6 hr) throughout the week may protect against pain sensitization and the development of chronic pain in females. Further research is needed, especially in patients with chronic pain.
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Affiliation(s)
- Shima Rouhi
- The University of Melbourne, Melbourne, Victoria, Australia
| | | | - Amy S Jordan
- The University of Melbourne, Melbourne, Victoria, Australia
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Bakken AG, Axén I, Eklund A, Warnqvist A, O'Neill S. Temporal stability and responsiveness of a conditioned pain modulation test. Scand J Pain 2023; 23:571-579. [PMID: 36869854 DOI: 10.1515/sjpain-2022-0084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 02/22/2023] [Indexed: 03/05/2023]
Abstract
OBJECTIVES Conditioned pain modulation is a commonly used quantitative sensory test, measuring endogenous pain control. The temporal stability of the test is questioned, and there is a lack of agreement on the effect of different pain conditions on the conditioned pain modulation response. Thus, an investigation of the temporal stability of a conditioned pain modulation test among patients suffering from persistent or recurrent neck pain is warranted. Further, an investigation into the difference between patients experiencing a clinically important improvement in pain and those not experiencing such an improvement will aid the understanding between changes in pain and the stability of the conditioned pain modulation test. METHODS This study is based on a randomized controlled trial investigating the effect of home stretching exercises and spinal manipulative therapy vs. home stretching exercises alone. As no difference was found between the interventions, all participants were studied as a prospective cohort in this study, investigating the temporal stability of a conditioned pain modulation test. The cohort was also divided into responders with a minimally clinically important improvement in pain and those not experiencing such an improvement. RESULTS Stable measurements of conditioned pain modulation were observed for all independent variables, with a mean change in individual CPM responses of 0.22 from baseline to one week with a standard deviation of 1.34, and -0.15 from the first to the second week with a standard deviation of 1.23. An Intraclass Correlation Coefficient (ICC3 - single, fixed rater) for CPM across the three time points yielded a coefficient of 0.54 (p<0.001). CONCLUSIONS Patients with persistent or recurrent neck pain had stable CPM responses over a 2 week course of treatment irrespective of clinical response.
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Affiliation(s)
- Anders Galaasen Bakken
- Department of Environmental Medicine, Unit of Intervention and Implementation Research for Worker Health, Karolinska Institutet, Stockholm, Sweden
| | - Iben Axén
- Department of Environmental Medicine, Unit of Intervention and Implementation Research for Worker Health, Karolinska Institutet, Stockholm, Sweden
| | - Andreas Eklund
- Department of Environmental Medicine, Unit of Intervention and Implementation Research for Worker Health, Karolinska Institutet, Stockholm, Sweden
| | - Anna Warnqvist
- Division of Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Søren O'Neill
- Spine Centre of Southern Denmark, University Hospital of Southern Denmark, Middelfart, Denmark
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Uzawa H, Ishii H, Ishida T, Shida T, Furuyama H, Nishida Y. Factors Associated with Low Inter-Session Reliability of Conditioned Pain Modulation in Older People with or Without Chronic Musculoskeletal Pain. J Pain Res 2023; 16:1039-1053. [PMID: 36992922 PMCID: PMC10041985 DOI: 10.2147/jpr.s391943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 03/16/2023] [Indexed: 03/31/2023] Open
Abstract
Purpose Conditioned pain modulation (CPM) is a measurement of the descending pain pathways that inhibit or facilitate afferent noxious stimuli. The reliability of CPM in older individuals with or without chronic musculoskeletal pain has not been sufficiently reported. This study aimed to examine the inter-session reliability of CPM in these cohorts and the factors in CPM reliability. Patients and Methods Individuals aged 65 or older were recruited in Narita, Japan. The measurements were performed on separate days 2 weeks apart (sessions 1 and 2). Each participant's hand was immersed in cold water, and we measured pressure pain threshold (PPT) before and after the immersion. The ratio before and after PPT measurements was presented as CPM index. The autonomic activities (heart rate variability, heart rate, and blood pressure) were simultaneously measured. An absolute reliability of CPM index was analyzed by the adjusted two-way analysis of variance (ANOVA) and the Bland Altman plot, and relative reliability was analyzed by intraclass correlation coefficient (ICC). Spearman's rho correlation and the adjusted multivariate regression analysis were utilized for examining the CPM reliability factors. Results Thirty-two participants were divided into two groups: chronic pain (n=19) and non-chronic pain (n=13) groups. The mean difference between session 1 and 2 in CPM index showed a systematic error in the chronic pain group at 17.3 (confidence interval, CI: 15.0 to 19.7), but none in the non-chronic pain group at 3.7 (CI: -0.02 to 7.4). The adjusted two-way ANOVA for CPM index did not identify any differences. ICC was not significant at p=-0.247 in the non-chronic and 0.167 in chronic pain. Multivariate regression analysis revealed total power and low/high frequencies as significant factors for CPM index. Conclusion This study identified low inter-session reliability in older adults with chronic musculoskeletal pain and autonomic nervous system activities as factors in CPM reliability.
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Affiliation(s)
- Hironobu Uzawa
- Department of Physical Therapy, International University of Health and Welfare, Narita, Chiba, Japan
- Correspondence: Hironobu Uzawa, Department of Physical Therapy, International University of Health and Welfare, 4-3, Kozunomori, Narita, Chiba, 286-8686, Japan, Tel/Fax +81-746-20-7716, Email
| | - Hideaki Ishii
- Department of Physical Therapy, International University of Health and Welfare, Narita, Chiba, Japan
| | - Takeki Ishida
- Department of Physical Therapy, International University of Health and Welfare, Narita, Chiba, Japan
| | - Takashi Shida
- Department of Medical Technology and Science, International University of Health and Welfare, Narita, Chiba, Japan
- Research Team for Promoting Independence and Mental Health, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo, Japan
| | - Hiroto Furuyama
- Department of Rehabilitation, International University of Health and Welfare Narita Hospital, Narita, Chiba, Japan
| | - Yusuke Nishida
- Department of Physical Therapy, International University of Health and Welfare, Narita, Chiba, Japan
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Sex-related differences in experimental pain sensitivity in subjects with painful or painless neuropathy after surgical repair of traumatic nerve injuries. Pain Rep 2022; 7:e1033. [PMID: 36284797 PMCID: PMC9586924 DOI: 10.1097/pr9.0000000000001033] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 05/10/2022] [Accepted: 07/17/2022] [Indexed: 12/01/2022] Open
Abstract
Higher pain intensities at all experimental stimuli but a tendency to faster recovery after cold conditioning stimuli were seen in women with neuropathy in comparison with men. Introduction: Sex-related influences represent a contributor to greater pain sensitivity and have a higher prevalence of many chronic pain conditions, including neuropathic pain (NP), among women. Objectives: The aim was to analyze how differences in ongoing pain, experimental pain intensity, and conditioned pain modulation (CPM) relate to sex in subjects with neuropathy after traumatic nerve injuries. Methods: Endogenous pain modulation was compared between male (n = 77) and female (n = 55) subjects and between subjects with NP (female = 31, male = 39) and pain-free subjects with posttraumatic neuropathy (female = 24, male = 38). Conditioned pain modulation was assessed by pain ratings to pressure stimuli before and after a noxious conditioning stimulus (CS) conducted with one arm submerged in cold water (4°C) for 1 minute. Time of recovery (Time off) of pain intensity from peak VASmaxc after CS was recorded and compared between male and female patients. Results: Greater ongoing pain intensity was found among female patients compared with male patients and more experimental pain after pressure and cold induced pain. Summing all groups together, women had 0.8 times higher odds (20%) of recovering sooner than men after CS (95% CI = 0.65–2.9). No differences in CPM, time off, and psychosocial variables were seen between female and male patients (P < 0.05). Conclusion: Our hypothesis for sex differences in endogenous pain modulation was only supported by a shorter after-sensation time after cold CS in female patients. No sex differences in the magnitude of CPM effect were identified. Increased pain intensity for experimental pain, in both neuropathic pain and neuropathy without pain, was found in female patients.
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Nuwailati R, Bobos P, Drangsholt M, Curatolo M. Reliability of conditioned pain modulation in healthy individuals and chronic pain patients: a systematic review and meta-analysis. Scand J Pain 2022; 22:262-278. [PMID: 35142147 DOI: 10.1515/sjpain-2021-0149] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 01/21/2022] [Indexed: 01/20/2023]
Abstract
OBJECTIVES Conditioned pain modulation (CPM) is a psychophysical parameter that is used to reflect the efficacy of endogenous pain inhibition. CPM reliability is important for research and potential clinical applications. The aim of this systematic review and meta-analysis was to evaluate the reliability of CPM tests in healthy individuals and chronic pain patients. METHODS We searched three databases for peer-reviewed studies published from inception to October 2020: EMBASE, Web of Science and NCBI. Risk of bias and the quality of the included studies were assessed. A meta-analysis with a random effects model was conducted to estimate intraclass correlation coefficients (ICCs). RESULTS Meta-analysis was performed on 25 papers that examined healthy participants (k=21) or chronic pain patients (k=4). The highest CPM intra-session reliability was with pressure as test stimulus (TS) and ischemic pressure (IP) or cold pressor test (CPT) as conditioning stimulus (CS) in healthy individuals (ICC 0.64, 95% CI 0.45-0.77), and pressure as TS with CPT as CS in patients (ICC 0.77, 95% CI 0.70-0.82). The highest inter-session ICC was with IP as TS and IP or CPT as CS (ICC 0.51, 95% CI 0.42-0.59) in healthy subjects. The only data available in patients for inter-session reliability were with pressure as TS and CPT as CS (ICC 0.44, 95% CI 0.11-0.69). Quality ranged from very good to excellent using the QACMRR checklist. The majority of the studies (24 out of 25) scored inadequate in Kappa coefficient reporting item of the COSMIN-ROB checklist. CONCLUSIONS Pressure and CPT were the TS and CS most consistently associated with good to excellent intra-session reliability in healthy volunteers and chronic pain patients. The inter-session reliability was fair or less for all modalities, both in healthy volunteers and chronic pain patients.
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Affiliation(s)
- Rania Nuwailati
- Department of Oral Health Sciences, University of Washington, Seattle, WA, USA
- Department of Oral Medicine, University of Washington, Seattle, WA, USA
| | - Pavlos Bobos
- Applied Health Research Centre (AHRC), The HUB, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada
- Department of Clinical Epidemiology and Health Care Research, Dalla Lana School of Public Health, Institute of Healthy Policy Management and Evaluation, University of Toronto, Toronto, ON, Canada
| | - Mark Drangsholt
- Department of Oral Health Sciences, University of Washington, Seattle, WA, USA
- Department of Oral Medicine, University of Washington, Seattle, WA, USA
| | - Michele Curatolo
- Department of Anesthesiology and Pain Medicine, School of Medicine, University of Washington, Seattle, WA, USA
- Harborview Injury Prevention and Research Center, Seattle, WA, USA
- CLEAR Research Center for Musculoskeletal Disorders, Seattle, WA, USA
- Department of Health Science and Technology, Center for Sensory-Motor Interaction, Aalborg University, Aalborg, Denmark
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Dams L, Haenen V, Van der Gucht E, Devoogdt N, Smeets A, Bernar K, De Vrieze T, De Groef A, Meeus M. Absolute and relative reliability of a comprehensive quantitative sensory testing protocol in women treated for breast cancer. PAIN MEDICINE 2021; 23:1162-1175. [PMID: 34908144 DOI: 10.1093/pm/pnab343] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 11/25/2021] [Accepted: 12/02/2021] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Quantitative sensory testing (QST) are non-invasive psychophysical assessment techniques to evaluate functioning of the somatosensory nervous system. Despite the importance of reliability for correct use of QST results in research and clinical practice, the relative and absolute intra-and inter-rater reliability of a comprehensive QST protocol to evaluate the functioning of both peripheral and central somatosensory nervous system in a breast cancer population, has not yet been investigated. SETTING University Hospitals, Leuven, Belgium. SUBJECTS Thirty women at least six months after unilateral breast cancer surgery. METHODS The protocol included nine static and dynamic QST methods (mechanical detection-pain thresholds, pressure pain thresholds, thermal detection-pain thresholds for heat and cold, temporal summation and conditioned pain modulation (CPM)) performed in the surgical area and more distant regions. Absolute and relative intra (60-minutes interval) and inter-rater (one-week interval) reliability was evaluated using intraclass correlation coefficients, standard error of measurement and Bland-Altman plots. RESULTS A moderate to excellent relative intra- and inter-rater reliability was found for the evaluation of mechanical thresholds, pressure pain thresholds and temporal summation. Reliability of the CPM paradigm was considered weak. Systematic bias between raters was noticed for detection of mechanical and cold stimuli at the non-affected trunk and CPM. CONCLUSIONS Except for the evaluation of CPM, the QST protocol was found suitable for identifying differences between subjects (relative reliability) and individual follow-up after breast cancer surgery (limited systematic bias) during a one-week timeframe. Additional research is required to determine measurement properties that influence CPM test stability in order to establish a more reliable CPM test paradigm.
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Affiliation(s)
- Lore Dams
- University of Antwerp, Faculty of Medicine and Health Sciences, Department of Rehabilitation Sciences and Physiotherapy, MOVANT, Antwerp, Belgium.,KU Leuven-University of Leuven, Department of Rehabilitation Sciences, Leuven, Belgium.,Pain In Motion International research group, www.paininmotion.be
| | - Vincent Haenen
- University of Antwerp, Faculty of Medicine and Health Sciences, Department of Rehabilitation Sciences and Physiotherapy, MOVANT, Antwerp, Belgium.,KU Leuven-University of Leuven, Department of Rehabilitation Sciences, Leuven, Belgium
| | - Elien Van der Gucht
- University of Antwerp, Faculty of Medicine and Health Sciences, Department of Rehabilitation Sciences and Physiotherapy, MOVANT, Antwerp, Belgium.,KU Leuven-University of Leuven, Department of Rehabilitation Sciences, Leuven, Belgium.,Pain In Motion International research group, www.paininmotion.be
| | - Nele Devoogdt
- KU Leuven-University of Leuven, Department of Rehabilitation Sciences, Leuven, Belgium.,Department of Vascular Surgery and Department of Physical Medicine and Rehabilitation, Center for Lymphedema, UZ Leuven-University Hospitals Leuven, Leuven, Belgium
| | - Ann Smeets
- Department of Surgical Oncology, University Hospitals Leuven, Leuven, Belgium
| | - Koen Bernar
- The Leuven Centre for Algology and Pain Management, University Hospitals Leuven, Leuven, Belgium
| | - Tessa De Vrieze
- KU Leuven-University of Leuven, Department of Rehabilitation Sciences, Leuven, Belgium
| | - An De Groef
- University of Antwerp, Faculty of Medicine and Health Sciences, Department of Rehabilitation Sciences and Physiotherapy, MOVANT, Antwerp, Belgium.,KU Leuven-University of Leuven, Department of Rehabilitation Sciences, Leuven, Belgium.,Pain In Motion International research group, www.paininmotion.be
| | - Mira Meeus
- University of Antwerp, Faculty of Medicine and Health Sciences, Department of Rehabilitation Sciences and Physiotherapy, MOVANT, Antwerp, Belgium.,Pain In Motion International research group, www.paininmotion.be.,Ghent University, Faculty of Medicine and Health Sciences, Department of Rehabilitation Sciences and Physiotherapy, Ghent, Belgium
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Kovacevic M, Klicov L, Vuklis D, Neblett R, Knezevic A. Test-retest reliability of pressure pain threshold and heat pain threshold as test stimuli for evaluation of conditioned pain modulation. Neurophysiol Clin 2021; 51:433-442. [PMID: 34304974 DOI: 10.1016/j.neucli.2021.06.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 06/29/2021] [Accepted: 06/29/2021] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVES There is growing interest in conditioned pain modulation (CPM) protocols for evaluating the function of the descending pain-modulatory system in clinical settings. The aim of this study was to evaluate test-retest reliability of a CPM protocol with contact heat as a conditioning stimulus (CS) and two test stimuli (pressure pain threshold (PPT) and heat pain threshold (HPT)), all applied within one session. In addition, gender and age differences were evaluated. METHODS The study included 87 healthy subjects (average age 37.95 ± 12.02 years, 57.5% females). The magnitude of the results of the CPM test was calculated as the difference between subject-reported pain thresholds before and after application of the CS. To assess the reliability of the protocol, a subgroup of 66 subjects underwent re-test after 14±1 days. In order to investigate the influence of age on the CPM magnitude, subjects were divided into subgroups (20-29, 30-39, 40-49, 50-59 years). RESULTS The pain thresholds for both test stimuli (TS) were significantly higher following the application of the CS (p < 0.001). Values of the interclass correlation coefficient (ICC) for the CPM with PPT as the TS indicated good reliability (ICC=0.631, 95% CI:0.365-0.782), while those for the HPT indicated poor reliability (ICC=0.328, 95% CI:-0.067-0.582). Significant differences in CPM between genders were found for both TS. Significant CPM differences were not detected among the four age subgroups for either TS. CONCLUSIONS CPM effects can be successfully induced with both PPT and HPT as a TS, but PPT showed significantly higher reliability.
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Affiliation(s)
| | - Ljiljana Klicov
- Medical Rehabilitation Clinic, Clinical Centre of Vojvodina, Novi Sad, Serbia
| | - Dragana Vuklis
- University of Novi Sad, Faculty of Medicine, Novi Sad, Serbia
| | - Randy Neblett
- PRIDE Research Foundation, Dallas, TX, United States of America
| | - Aleksandar Knezevic
- University of Novi Sad, Faculty of Medicine, Novi Sad, Serbia; Medical Rehabilitation Clinic, Clinical Centre of Vojvodina, Novi Sad, Serbia
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Ramaswamy S, Wodehouse T. Conditioned pain modulation-A comprehensive review. Neurophysiol Clin 2020; 51:197-208. [PMID: 33334645 DOI: 10.1016/j.neucli.2020.11.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 11/25/2020] [Accepted: 11/28/2020] [Indexed: 01/05/2023] Open
Abstract
Conditioned pain modulation (CPM) is a centrally processed measure of the net effect of the descending pain pathway. This comprises both the facilitatory as well as the inhibitory effect. In the past, CPM or similar effects have been previously described using different terminologies such as diffuse noxious inhibitory control (DNIC), heterotopic noxious conditioning stimulation (HNCS) or endogenous analgesia (EA). A variety of patient-related factors such as age, gender, hormones, race, genetic and psychological factors have been thought to influence the CPM paradigms. CPM paradigms have also been associated with a wide range of methodological variables including the mode of application of the 'test' as well as the 'conditioning' stimuli. Despite all these variabilities, CPM seems to reliably lend itself to the pain modulation profile concept and could in future become one of the phenotypic biomarkers for pain and also a guide for mechanism-based treatment in chronic pain. Future research should focus on establishing consistent methodologies for measuring CPM and thereby enhancing the robustness of this emerging biomarker for pain.
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Affiliation(s)
- Shankar Ramaswamy
- 1St Bartholomew's Hospital, Bart's Health NHS Trust, London, EC1A 4AS, UK.
| | - Theresa Wodehouse
- 1St Bartholomew's Hospital, Bart's Health NHS Trust, London, EC1A 4AS, UK
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Tan B, Philipp M, Hill S, Che Muhamed AM, Mündel T. Pain Across the Menstrual Cycle: Considerations of Hydration. Front Physiol 2020; 11:585667. [PMID: 33132918 PMCID: PMC7578918 DOI: 10.3389/fphys.2020.585667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/16/2020] [Indexed: 11/20/2022] Open
Abstract
Chronic pain – pain that persists for more than 3 months – is a global health problem and is associated with tremendous social and economic cost. Yet, current pain treatments are often ineffective, as pain is complex and influenced by numerous factors. Hypohydration was recently shown to increase ratings of pain in men, but studies in this area are limited (n = 3). Moreover, whether hypohydration also affects pain in women has not been examined. In women, changes in the concentrations of reproductive hormones across menstrual phases may affect pain, as well as the regulation of body water. This indicates potential interactions between the menstrual phase and hypohydration on pain, but this hypothesis has yet to be tested. This review examined the literature concerning the effects of the menstrual phase and hypohydration on pain, to explore how these factors may interact to influence pain. Future research investigating the combined effects of hypohydration and menstrual phase on pain is warranted, as the findings could have important implications for the treatment of pain in women, interpretation of previous research and the design of future studies.
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Affiliation(s)
- Beverly Tan
- School of Sport, Exercise and Nutrition, Massey University, Palmerston North, New Zealand
| | - Michael Philipp
- School of Psychology, Massey University, Palmerston North, New Zealand
| | - Stephen Hill
- School of Psychology, Massey University, Palmerston North, New Zealand
| | | | - Toby Mündel
- School of Sport, Exercise and Nutrition, Massey University, Palmerston North, New Zealand
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Effects of Conditioned Pain Modulation on the Nociceptive Flexion Reflex in Healthy People: A Systematic Review. Clin J Pain 2020; 35:794-807. [PMID: 31268892 DOI: 10.1097/ajp.0000000000000724] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVES The nociceptive flexion reflex (NFR) is a spinal reflex induced by painful stimuli resulting in a withdrawal response. Research has shown that the NFR is inhibited through endogenous pain inhibitory mechanisms, which can be assessed by conditioned pain modulation (CPM) paradigms. Although accumulating research suggests that the NFR can be affected by CPM, no clear overview of the current evidence exists. Therefore, the present review aimed at providing such a synthesis of the literature. In addition, the influence of personal factors on the CPM of the NFR was investigated. MATERIALS AND METHODS A systematic review was performed and reported following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Five electronic databases were searched to identify relevant articles. Retrieved articles were screened on eligibility using predefined inclusion criteria. Risk of bias was investigated according to the modified Newcastle-Ottawa Scale. Levels of evidence and strength of conclusion were assigned following the guidelines of the Dutch Institute for Healthcare Improvement. RESULTS Forty articles were included. There is some evidence that CPM produced by thermal or mechanical stimuli induces inhibitory effects on the NFR. However, inconclusive evidence exists with regard to the effect of electrical conditioning stimuli. While several personal factors do not affect CPM of the NFR, increased cognitive interference is associated with reduced NFR inhibition. DISCUSSION The present review demonstrates that certain types of nociceptive conditioning stimuli have the potential to depress, at the spinal level, nociceptive stimuli elicited from distant body regions. Although CPM of the NFR seems to be robust to the influence of several personal factors, it can be affected by cognitive influences.
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Nuwailati R, Curatolo M, LeResche L, Ramsay DS, Spiekerman C, Drangsholt M. Reliability of the conditioned pain modulation paradigm across three anatomical sites. Scand J Pain 2020; 20:283-296. [PMID: 31812949 DOI: 10.1515/sjpain-2019-0080] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 10/24/2019] [Indexed: 01/08/2023]
Abstract
Background and aims Conditioned Pain Modulation (CPM) is a measure of pain inhibition-facilitation in humans that may elucidate pain mechanisms and potentially serve as a diagnostic test. In laboratory settings, the difference between two pain measures [painful test stimulus (TS) without and with the conditioning stimulus (CS) application] reflects the CPM magnitude. Before the CPM test can be used as a diagnostic tool, its reliability on the same day (intra-session) and across multiple days (inter-session) needs to be known. Furthermore, it is important to determine the most reliable anatomical sites for both the TS and the CS. This study aimed to measure the intra-session and inter-session reliability of the CPM test paradigm in healthy subjects with the TS (pressure pain threshold-PPT) applied to three test sites: the face, hand, and dorsum of the foot, and the CS (cold pressor test-CPT) applied to the contralateral hand. Methods Sixty healthy participants aged 18-65 were tested by the same examiner on 3 separate days, with an interval of 2-7 days. On each day, testing was comprised of two identical experimental sessions in which the PPT test was performed on each of the three dominant anatomical sites in randomized order followed by the CPM test (repeating the PPT with CPT on the non-dominant hand). CPM magnitude was calculated as the percent change in PPT. The Intraclass Correlation Coefficient (ICC), Coefficient of Variation (CV), and Bland-Altman analyses were used to assess reliability. Results PPT relative reliability ranged from good to excellent at all three sites; the hand showed an intra-session ICC of 0.90 (0.84, 0.94) before CPT and ICC of 0.89 (0.83, 0.92) during CPT. The PPT absolute reliability was also high, showing a low bias and small variability when performed on all three sites; for example, CV of the hand intra-session was 8.0 before CPT and 8.1 during CPT. The relative reliability of the CPM test, although only fair, was most reliable when performed during the intra-session visits on the hand; ICC of 0.57 (0.37, 0.71) vs. 0.20 (0.03, 0.39) for the face, and 0.22 (0.01, 0.46) for the foot. The inter-session reliability was lower in all three anatomical sites, with the best reliability on the hand with an ICC of 0.40 (0.23, 0.55). The pattern of absolute reliability of CPM was similar to the relative reliability findings, with the reliability best on the hand, showing lower intra-session and inter-session variability (CV% = 43.5 and 51.5, vs. 70.1 and 73.1 for the face, and 75.9 and 78.9 for the foot). The CPM test was more reliable in women than in men, and in older vs. younger participants. Discussion The CPM test was most reliable when the TS was applied to the dominant hand and CS performed on the contralateral hand. These data indicate that using the CS and TS in the same but contralateral dermatome in CPM testing may create the most reliable results.
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Affiliation(s)
- Rania Nuwailati
- Department of Oral Health Sciences, University of Washington, Seattle, WA, USA
| | - Michele Curatolo
- Department of Anesthesiology and Pain Medicine, School of Medicine, University of Washington, Seattle, WA, USA.,Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Linda LeResche
- Department of Oral Health Sciences, University of Washington, Seattle, WA, USA.,Department of Oral Medicine, University of Washington, Seattle, WA, USA
| | - Douglas S Ramsay
- Department of Oral Health Sciences, University of Washington, Seattle, WA, USA.,Department of Orthodontics, University of Washington, Seattle, WA, USA.,Department of Pediatric Dentistry, University of Washington, Seattle, WA, USA
| | - Charles Spiekerman
- Department of Oral Health Sciences, University of Washington, Seattle, WA, USA.,Department of Biostatistics, School of Public Health, University of Washington, Seattle, WA, USA
| | - Mark Drangsholt
- Department of Oral Health Sciences, University of Washington, Seattle, WA, USA.,Department of Oral Medicine, University of Washington, Seattle, WA, USA
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Kennedy DL, Kemp HI, Wu C, Ridout DA, Rice ASC. Determining Real Change in Conditioned Pain Modulation: A Repeated Measures Study in Healthy Volunteers. THE JOURNAL OF PAIN 2019; 21:708-721. [PMID: 31715262 DOI: 10.1016/j.jpain.2019.09.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 08/29/2019] [Accepted: 09/19/2019] [Indexed: 11/17/2022]
Abstract
Conditioned pain modulation (CPM) is a potentially useful biomarker in pain populations; however, a statistically robust interpretation of change scores is required. Currently, reporting of CPM does not consider measurement error. Hence, the magnitude of change representing a "true" CPM effect is unknown. This study determined the standard error of measurement (SEM) and proportion of healthy participants showing a "true" CPM effect with a standard CPM paradigm. Fifty healthy volunteers participated in an intersession reliability study using pressure pain threshold (PPT) test stimulus and contact heat, cold water, and sham conditioning stimuli. Baseline PPTs were used to calculate SEM and >±2 × SEM to determine CPM effect. SEM for PPT was .21 kg/cm2. An inhibitory CPM effect (>+2 SEM) was elicited in 59% of subjects in response to cold stimulus; in 44% to heat. Intrasession and intersession reliability of within-subject CPM response was poor (kappa coefficient <.36). Measurement error is important in determining CPM effect and change over time. Even when using reliable test stimuli, and incorporating measures to limit bias and error, CPM intersession reliability was fair and demonstrated a large degree of within-subject variation. Determining "true" change in CPM will underpin future interrogations of intraindividual differences in CPM. PERSPECTIVE: This study used a distribution-based statistical approach to identify real change in CPM, based on the SEM for the test stimulus. Healthy volunteers demonstrate substantial within-subject variation; CPM effect was paradigm dependent at intrasession testing and unstable to the same paradigm at intersession testing.
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Affiliation(s)
- Donna L Kennedy
- Pain Research Group, Department of Surgery & Cancer, Imperial College London, United Kingdom.
| | - Harriet I Kemp
- Pain Research Group, Department of Surgery & Cancer, Imperial College London, United Kingdom
| | - Chenxian Wu
- Imperial College London School of Medicine, United Kingdom
| | - Deborah A Ridout
- Population, Policy and Practice Programme, UCL Great Ormond Street Institute of Child Health, University College London, United Kingdom
| | - Andrew S C Rice
- Pain Research Group, Department of Surgery & Cancer, Imperial College London, United Kingdom
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Lie MU, Petriu E, Matre D, Hansson P, Andersen OK, Zwart JA, Nilsen KB. Psychophysical or spinal reflex measures when assessing conditioned pain modulation? Eur J Pain 2019; 23:1879-1889. [PMID: 31359580 DOI: 10.1002/ejp.1462] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 07/05/2019] [Accepted: 07/23/2019] [Indexed: 01/31/2023]
Abstract
BACKGROUND Assessing conditioning pain modulation (CPM) with spinal reflex measures may produce more objective and stable CPM effects than using psychophysical measures. The aim of the study was to compare the CPM effect and test-retest reliability between a psychophysical protocol with thermal test-stimulus and a spinal reflex protocol with electrical test-stimulus. METHODS Twenty-five healthy volunteers participated in two identical experiments separated by minimum 1 week. The thermal test-stimulus was a constant heat stimulation of 120 s on the subjects' forearm with continuous ratings of pain intensity on a 10 cm visual analogue scale. The electrical test-stimulus was repeated electrical stimulation on the arch of the foot for 120 s, which elicited a nociceptive withdrawal reflex recorded from the anterior tibial muscle. Conditioning stimulus was a 7°C water bath. Differences in the magnitude and test-retest reliability were investigated with repeated-measures analysis of variance and by relative and absolute reliability indices. RESULTS The CPM effect was -46% and 4.5% during the thermal and electrical test-stimulus (p < 0.001) respectively. Intraclass correlation coefficient of 0.5 and 0.4 was found with the electrical and thermal test-stimulus respectively. Wide limits of agreement were found for both the electrical (-3.4 to 3.8 mA) and the thermal test-stimulus (-3.2 to 3.6 cm). CONCLUSIONS More pronounced CPM effect was demonstrated when using a psychophysical protocol with thermal test-stimulus compared to a spinal reflex protocol with electrical test-stimulus. Fair relative reliability and poor absolute reliability (due to high intraindividual variability) was found in both protocols. SIGNIFICANCE The large difference in CPM effect between the two protocols suggests that the CPM effect relates to pain perception rather than nociception on the spinal level. Due to poor absolute intrarater reliability, we recommend caution and further research before using any of the investigated CPM protocols in clinical decision making on an individual level.
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Affiliation(s)
- Marie Udnesseter Lie
- Research and Communication Unit for Musculoskeletal Health (FORMI), Oslo University Hospital, Oslo, Norway.,Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Elena Petriu
- Faculty of Health Science, Oslo Metropolitan University, Oslo, Norway.,Department of Neurology, Oslo University Hospital, Oslo, Norway
| | - Dagfinn Matre
- Department of Work Psychology and Physiology, National Institute of Occupational Health, Oslo, Norway
| | - Per Hansson
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Department of Pain Management and Research, Division of Emergencies and Critical Care, Oslo University Hospital, Oslo, Norway
| | - Ole Kaeseler Andersen
- Center for Neuroplasticity and Pain (CNAP), SMI®, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - John-Anker Zwart
- Research and Communication Unit for Musculoskeletal Health (FORMI), Oslo University Hospital, Oslo, Norway.,Faculty of Medicine, University of Oslo, Oslo, Norway.,Department of Neurology, Oslo University Hospital, Oslo, Norway
| | - Kristian Bernhard Nilsen
- Research and Communication Unit for Musculoskeletal Health (FORMI), Oslo University Hospital, Oslo, Norway.,Department of Neurology, Oslo University Hospital, Oslo, Norway.,Department of Neuromedicine and Movement Science, Norwegian University of Science and Technology, Trondheim, Norway
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Moana-Filho EJ, Herrero Babiloni A. Endogenous pain modulation in chronic temporomandibular disorders: Derivation of pain modulation profiles and assessment of its relationship with clinical characteristics. J Oral Rehabil 2018; 46:219-232. [DOI: 10.1111/joor.12745] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 09/26/2018] [Accepted: 10/31/2018] [Indexed: 01/14/2023]
Affiliation(s)
- Estephan J. Moana-Filho
- Division of TMD & Orofacial Pain, School of Dentistry; University of Minnesota; Minneapolis Minnesota
| | - Alberto Herrero Babiloni
- Division of TMD & Orofacial Pain, School of Dentistry; University of Minnesota; Minneapolis Minnesota
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15
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Vaegter HB, Lyng KD, Yttereng FW, Christensen MH, Sørensen MB, Graven-Nielsen T. Exercise-Induced Hypoalgesia After Isometric Wall Squat Exercise: A Test-Retest Reliabilty Study. PAIN MEDICINE 2018; 20:129-137. [DOI: 10.1093/pm/pny087] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Henrik Bjarke Vaegter
- Pain Research Group, Pain Center, Department of Anesthesiology and Intensive Care Medicine, University Hospital Odense, Odense, Denmark
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark
| | | | | | | | | | - Thomas Graven-Nielsen
- Department of Health Science and Technology, Faculty of Medicine, Center for Neuroplasticity and Pain (CNAP), SMI, Aalborg University, Aalborg, Denmark
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16
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A tonic heat test stimulus yields a larger and more reliable conditioned pain modulation effect compared to a phasic heat test stimulus. Pain Rep 2017; 2:e626. [PMID: 29392240 PMCID: PMC5741326 DOI: 10.1097/pr9.0000000000000626] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 08/15/2017] [Accepted: 09/13/2017] [Indexed: 11/26/2022] Open
Abstract
Introduction The interest in conditioned pain modulation (CPM) as a clinical tool for measuring endogenously induced analgesia is increasing. There is, however, large variation in the CPM methodology, hindering comparison of results across studies. Research comparing different CPM protocols is needed in order to obtain a standardized test paradigm. Objectives The aim of the study was to assess whether a protocol with phasic heat stimuli as test-stimulus is preferable to a protocol with tonic heat stimulus as test-stimulus. Methods In this experimental crossover study, we compared 2 CPM protocols with different test-stimulus; one with tonic test-stimulus (constant heat stimulus of 120-second duration) and one with phasic test-stimuli (3 heat stimulations of 5 seconds duration separated by 10 seconds). Conditioning stimulus was a 7°C water bath in parallel with the test-stimulus. Twenty-four healthy volunteers were assessed on 2 occasions with minimum 1 week apart. Differences in the magnitude and test-retest reliability of the CPM effect in the 2 protocols were investigated with repeated-measures analysis of variance and by relative and absolute reliability indices. Results The protocol with tonic test-stimulus induced a significantly larger CPM effect compared to the protocol with phasic test-stimuli (P < 0.001). Fair and good relative reliability was found with the phasic and tonic test-stimuli, respectively. Absolute reliability indices showed large intraindividual variability from session to session in both protocols. Conclusion The present study shows that a CPM protocol with a tonic test-stimulus is preferable to a protocol with phasic test-stimuli. However, we emphasize that one should be cautious to use the CPM effect as biomarker or in clinical decision making on an individual level due to large intraindividual variability.
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Abstract
Supplemental Digital Content is Available in the Text. A systematic literature review was undertaken to determine if conditioned pain modulation (CPM) is reliable. Longitudinal, English language observational studies of the repeatability of a CPM test paradigm in adult humans were included. Two independent reviewers assessed the risk of bias in 6 domains; study participation; study attrition; prognostic factor measurement; outcome measurement; confounding and analysis using the Quality in Prognosis Studies (QUIPS) critical assessment tool. Intraclass correlation coefficients (ICCs) less than 0.4 were considered to be poor; 0.4 and 0.59 to be fair; 0.6 and 0.75 good and greater than 0.75 excellent. Ten studies were included in the final review. Meta-analysis was not appropriate because of differences between studies. The intersession reliability of the CPM effect was investigated in 8 studies and reported as good (ICC = 0.6-0.75) in 3 studies and excellent (ICC > 0.75) in subgroups in 2 of those 3. The assessment of risk of bias demonstrated that reporting is not comprehensive for the description of sample demographics, recruitment strategy, and study attrition. The absence of blinding, a lack of control for confounding factors, and lack of standardisation in statistical analysis are common. Conditioned pain modulation is a reliable measure; however, the degree of reliability is heavily dependent on stimulation parameters and study methodology and this warrants consideration for investigators. The validation of CPM as a robust prognostic factor in experimental and clinical pain studies may be facilitated by improvements in the reporting of CPM reliability studies.
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18
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Höffken O, Özgül ÖS, Enax-Krumova EK, Tegenthoff M, Maier C. Evoked potentials after painful cutaneous electrical stimulation depict pain relief during a conditioned pain modulation. BMC Neurol 2017; 17:167. [PMID: 28851323 PMCID: PMC5575837 DOI: 10.1186/s12883-017-0946-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 08/21/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Conditioned pain modulation (CPM) evaluates the pain modulating effect of a noxious conditioning stimulus (CS) on another noxious test stimulus (TS), mostly based solely on subjective pain ratings. We used painful cutaneous electrical stimulation (PCES) to induce TS in a novel CPM-model. Additionally, to evaluate a more objective parameter, we recorded the corresponding changes of cortical evoked potentials (PCES-EP). METHODS We examined the CPM-effect in 17 healthy subjects in a randomized controlled cross-over design during immersion of the non-dominant hand into 10 °C or 24 °C cold water (CS). Using three custom-built concentric surface electrodes, electrical stimuli were applied on the dominant hand, inducing pain of 40-60 on NRS 0-100 (TS). At baseline, during and after CS we assessed the electrically induced pain intensity and electrically evoked potentials recorded over the central electrode (Cz). RESULTS Only in the 10 °C-condition, both pain (52.6 ± 4.4 (baseline) vs. 30.3 ± 12.5 (during CS)) and amplitudes of PCES-EP (42.1 ± 13.4 μV (baseline) vs. 28.7 ± 10.5 μV (during CS)) attenuated during CS and recovered there after (all p < 0.001). In the 10 °C-condition changes of subjective pain ratings during electrical stimulation and amplitudes of PCES-EP correlated significantly with each other (r = 0.5) and with CS pain intensity (r = 0.5). CONCLUSIONS PCES-EPs are a quantitative measure of pain relief, as changes in the electrophysiological response are paralleled by a consistent decrease in subjective pain ratings. This novel CPM paradigm is a feasible method, which could help to evaluate the function of the endogenous pain modulation processes. TRIAL REGISTRATION German Clinical Trials Register DRKS-ID: DRKS00012779 , retrospectively registered on 24 July 2017.
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Affiliation(s)
- Oliver Höffken
- Department of Neurology, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil GmbH, Ruhr-University Bochum, Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Germany.
| | - Özüm S Özgül
- Department of Neurology, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil GmbH, Ruhr-University Bochum, Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Germany
| | - Elena K Enax-Krumova
- Department of Neurology, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil GmbH, Ruhr-University Bochum, Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Germany
| | - Martin Tegenthoff
- Department of Neurology, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil GmbH, Ruhr-University Bochum, Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Germany
| | - Christoph Maier
- Department of Pain Medicine, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil GmbH, Ruhr-University Bochum, Bürkle-de-la-Camp-Platz 1, 44789, Bochum, Germany
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19
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Mackey IG, Dixon EA, Johnson K, Kong JT. Dynamic Quantitative Sensory Testing to Characterize Central Pain Processing. J Vis Exp 2017. [PMID: 28287532 PMCID: PMC5407598 DOI: 10.3791/54452] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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.
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Affiliation(s)
- Ian G Mackey
- Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine
| | - Eric A Dixon
- Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine
| | - Kevin Johnson
- Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine
| | - Jiang-Ti Kong
- Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine;
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20
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Norouzi F, Abareshi A, Asgharzadeh F, Beheshti F, Hosseini M, Farzadnia M, Khazaei M. The effect of Nigella sativa on inflammation-induced myocardial fibrosis in male rats. Res Pharm Sci 2017; 12:74-81. [PMID: 28255317 PMCID: PMC5333483 DOI: 10.4103/1735-5362.199050] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Nigella sativa (NS) (Ranunculaceae) used as a protective and therapeutic traditional medicine. This study evaluates the effect of NS on inflammation-induced myocardial fibrosis, serum and tissue inflammatory markers, and oxidative stress status in male rats. Fifty male Wistar rats were divided into five groups: (1) control; (2) lipopolysaccharide (LPS), 1 mg/kg/day; (3) LPS + NS (hydroalcoholic extract), 100 mg/kg/day; (4) LPS + NS, 200 mg/kg/day; (5) LPS + NS, 400 mg/kg/day (n = 10 in each group). The duration of LPS administration was two weeks. At the end of the experiment, blood samples were taken and ventricles were homogenized and stained for histological evaluation. Serum nitrite levels were lower in LPS group than the control group (22.98 ± 1.03 vs 28.5 ± 0.93 μmol/L), in which they were significantly increased by NS treatment (P < 0.05). Higher levels of heart interlukine-6 (IL-6) and tumor necrosis factor-α (TNF-α) were observed in LPS group compared to the controls (IL-6: 6805 ± 656 vs 4733 ± 691 pg/mL; TNF-α: 6504 ± 501 vs 5309 ± 452 pg/mL), in which they were reduced by NS 400 mg/kg compared to LPS groups (P < 0.05). A significant increment of malondialdehyde and reduction in heart total thiol, superoxide dismutase and catalase concentrations were observed in LPS group (p < 0.05) which significantly restored with treatment by three doses of NS. Histopathological studies showed higher inflammatory cell infiltrates, cardiac fibrosis, and collagen deposition in LPS group, which were reduced by the administration of NS. Treatment by NS reduced myocardial fibrosis in inflammation-induced fibrosis, possibly through improving oxidative/anti-oxidative balance.
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Affiliation(s)
- Fatemeh Norouzi
- Department of Physiology, School of Medicine, Esfarayan Faculty of Medical Sciences, Esfarayan, I.R. Iran; Neurogenic Inflammation Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, I.R. Iran
| | - Azam Abareshi
- Department of Physiology, School of Medicine, Esfarayan Faculty of Medical Sciences, Esfarayan, I.R. Iran
| | - Fereshteh Asgharzadeh
- Neurogenic Inflammation Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, I.R. Iran
| | - Farimah Beheshti
- Neurogenic Inflammation Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, I.R. Iran
| | - Mahmoud Hosseini
- Neurocognitive Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, I.R. Iran
| | - Mehdi Farzadnia
- Department of Pathology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, I.R. Iran
| | - Majid Khazaei
- Neurogenic Inflammation Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, I.R. Iran
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Bossmann T, Brauner T, Lowak H, Anton F, Forster C, Horstmann T. Reliability of conditioned pain modulation for the assessment of endogenous pain control pathways. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.npbr.2016.09.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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22
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Graven-Nielsen T, Izumi M, Petersen KK, Arendt-Nielsen L. User-independent assessment of conditioning pain modulation by cuff pressure algometry. Eur J Pain 2016; 21:552-561. [PMID: 27859944 DOI: 10.1002/ejp.958] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2016] [Indexed: 01/04/2023]
Abstract
BACKGROUND The use of conditioning pain modulation (CPM) is hampered by poor reproducibility and lack of user-independent paradigms. This study refined the CPM paradigm by applying user-independent cuff algometry. METHODS In 20 subjects, the CPM effect of conditioning with cuff stimulation on the arm was investigated by pain test stimuli on the contralateral leg before and in parallel with different cuff conditionings (10, 30, 60 kPa/60 s; 30, 60 kPa/10 s). As test stimulus, another cuff was inflated (1 kPa/s) until the subjects detected the pain tolerance threshold (PTT) during which the pain detection threshold (PDT) and the pressure at a pain intensity of 6 cm on a 10-cm visual analogue scale (PVAS6) were extracted. For comparison, pressure pain thresholds (PPTs) as test stimuli were recorded by the user-dependent handheld pressure algometry. Combinations of cuff locations for conditioning (pain intensity standardized) and contralateral test stimuli were additionally evaluated (leg-arm, leg-leg, arm-thigh). The test-retest reliability in two sessions 1 month apart was assessed in five CPM protocols. RESULTS In all protocols, the PDT, PVAS6 and PTT increased during conditioning compared with baseline (p < 0.05). The CPM effect (i.e. conditioning minus baseline) for PVAS6, PTT and PPT increased for increasing conditioning intensities (p < 0.05). The CPM effects were not significantly different for changes in conditioning durations or conditioning/test stimulus locations. In two sessions, the CPM effects for PVAS6 and PTT assessed after 60 s of conditioning on the leg/thigh showed the highest intra-class correlations (0.47-0.73), where they were 0.04-0.6 for PPTs. CONCLUSIONS The user-independent cuff algometry is reliable for CPM assessment and for supra-pain threshold test stimuli better than the user-dependent technology. SIGNIFICANCE A user-independent CPM technique where the conditioning is controlled by one cuff stimulation, and the test-stimulus is provided by another cuff stimulation. This study shows that cuff algometry is reliable for CPM assessment.
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Affiliation(s)
- T Graven-Nielsen
- Center for Neuroplasticity and Pain (CNAP), SMI, Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Denmark
| | - M Izumi
- Center for Neuroplasticity and Pain (CNAP), SMI, Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Denmark.,Department of Orthopaedic Surgery, Kochi University, Japan
| | - K K Petersen
- Center for Neuroplasticity and Pain (CNAP), SMI, Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Denmark
| | - L Arendt-Nielsen
- Center for Neuroplasticity and Pain (CNAP), SMI, Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Denmark
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Imai Y, Petersen KK, Mørch CD, Arendt Nielsen L. Comparing test-retest reliability and magnitude of conditioned pain modulation using different combinations of test and conditioning stimuli. Somatosens Mot Res 2016; 33:169-177. [PMID: 27650216 DOI: 10.1080/08990220.2016.1229178] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
This study aimed to compare the reliability and magnitude of conditioned pain modulation (CPM) by applying different test stimuli (TS) and conditioning stimuli (CS). Twenty-six healthy male participants were recruited in the study of two identical sessions. In each session, four TS (electrical, heat, handheld, and cuff pressure algometry) were applied before and during CS (cold pressor test (CPT) or cuff algometry). The same procedure was repeated with 45-min intervals, but with the other CS. Five thresholds were measured including four pain detection thresholds from four TS and pain tolerance threshold from cuff TS (cuff PTT). Intraclass correlation coefficient (ICC (3,1)) and coefficient of variation (CV) were calculated as measures of reliability. The reliability of TS before and during CS was good for all combinations (ICC: 0.60-0.96, CV: 2.2-22.9%), but the reliability of the CPM effect varied (ICC: 0.04-0.53, CV: 63.6-503.9%). The most reliable combinations were considered to be the handheld pressure pain threshold with CPT (ICC: 0.49, CV: 63.6%) and the cuff pressure pain threshold with CPT (ICC: 0.44, CV: 107.6%). Significant CPM effects were found for all combinations, except the combinations of electrical and heat pain thresholds with cuff CS, which indicates the novel classification of the CPM mechanism. The combinations of handheld pressure and heat pain threshold with CPT would provide the minimum sample size to detect the significant CPM changes in further studies. It is beneficial to provide and compare both ICC and CV to design further clinical trials.
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Affiliation(s)
- Y Imai
- a Department of Health Science and Technology , Aalborg University , Aalborg , Denmark.,b Clinical Development Department , Asahi Kasei Pharma Corporation , Tokyo , Japan
| | - K K Petersen
- a Department of Health Science and Technology , Aalborg University , Aalborg , Denmark
| | - C D Mørch
- a Department of Health Science and Technology , Aalborg University , Aalborg , Denmark
| | - L Arendt Nielsen
- a Department of Health Science and Technology , Aalborg University , Aalborg , Denmark
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24
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Gehling J, Mainka T, Vollert J, Pogatzki-Zahn EM, Maier C, Enax-Krumova EK. Short-term test-retest-reliability of conditioned pain modulation using the cold-heat-pain method in healthy subjects and its correlation to parameters of standardized quantitative sensory testing. BMC Neurol 2016; 16:125. [PMID: 27495743 PMCID: PMC4974731 DOI: 10.1186/s12883-016-0650-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Accepted: 07/27/2016] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Conditioned Pain Modulation (CPM) is often used to assess human descending pain inhibition. Nine different studies on the test-retest-reliability of different CPM paradigms have been published, but none of them has investigated the commonly used heat-cold-pain method. The results vary widely and therefore, reliability measures cannot be extrapolated from one CPM paradigm to another. Aim of the present study was to analyse the test-retest-reliability of the common heat-cold-pain method and its correlation to pain thresholds. METHODS We tested the short-term test-retest-reliability within 40 ± 19.9 h using a cold-water immersion (10 °C, left hand) as conditioning stimulus (CS) and heat pain (43-49 °C, pain intensity 60 ± 5 on the 101-point numeric rating scale, right forearm) as test stimulus (TS) in 25 healthy right-handed subjects (12females, 31.6 ± 14.1 years). The TS was applied 30s before (TSbefore), during (TSduring) and after (TSafter) the 60s CS. The difference between the pain ratings for TSbefore and TSduring represents the early CPM-effect, between TSbefore and TSafter the late CPM-effect. Quantitative sensory testing (QST, DFNS protocol) was performed on both sessions before the CPM assessment. STATISTICS paired t-tests, Intraclass correlation coefficient (ICC), standard error of measurement (SEM), smallest real difference (SRD), Pearson's correlation, Bland-Altman analysis, significance level p < 0.05 with Bonferroni correction for multiple comparisons, when necessary. RESULTS Pain ratings during CPM correlated significantly (ICC: 0.411…0.962) between both days, though ratings for TSafter were lower on day 2 (p < 0.005). The early (day 1: 16.7 ± 11.7; day 2: 19.5 ± 11.9; ICC: 0.618, SRD: 20.2) and late (day 1: 1.7 ± 9.2; day 2: 7.6 ± 11.5; ICC: 0.178, SRD: 27.0) CPM effect did not differ significantly between both days. Both early and late CPM-effects did not correlate with the pain thresholds. CONCLUSIONS The short-term test-retest-reliability of the early CPM-effect using the heat-cold-pain method in healthy subjects achieved satisfying results in terms of the ICC. The SRD of the early CPM effect showed that an individual change of > 20 NRS can be attributed to a real change rather than chance. The late CPM-effect was weaker and not reliable.
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Affiliation(s)
- Julia Gehling
- Department of Pain Medicine, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil GmbH, Ruhr-University Bochum, Bürkle-de-la-Camp-Platz 1, 44789 Bochum, Germany
| | - Tina Mainka
- Department of Pain Medicine, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil GmbH, Ruhr-University Bochum, Bürkle-de-la-Camp-Platz 1, 44789 Bochum, Germany
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246 Hamburg, Germany
| | - Jan Vollert
- Department of Pain Medicine, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil GmbH, Ruhr-University Bochum, Bürkle-de-la-Camp-Platz 1, 44789 Bochum, Germany
| | - Esther M. Pogatzki-Zahn
- Department of Anaesthesiology, Intensive Care and Pain Medicine, University Hospital Münster, Albert-Schweitzer-Campus 1, GB A1, 48149 Münster, Germany
| | - Christoph Maier
- Department of Pain Medicine, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil GmbH, Ruhr-University Bochum, Bürkle-de-la-Camp-Platz 1, 44789 Bochum, Germany
| | - Elena K. Enax-Krumova
- Department of Neurology, Berufsgenossenschaftliches Universitätsklinikum Bergmannsheil GmbH, Ruhr-University Bochum, Bürkle-de-la-Camp-Platz 1, 44789 Bochum, Germany
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Nahman-Averbuch H, Sprecher E, Jacob G, Yarnitsky D. The Relationships Between Parasympathetic Function and Pain Perception: The Role of Anxiety. Pain Pract 2016; 16:1064-1072. [PMID: 26878998 DOI: 10.1111/papr.12407] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 10/09/2015] [Indexed: 11/28/2022]
Abstract
BACKGROUND Previous studies have identified relationships between autonomic function and pain perception. Anxiety was found to influence both autonomic and pain responses. We examined the effect of anxiety level on parasympathetic function and pain perception as well as on the relationships between these 2 systems. METHODS Thirty healthy females were divided into high- and low-anxiety groups according to their trait anxiety levels. Parasympathetic function was obtained using heart rate variability, deep breathing, and Valsalva ratios. Pain perception parameters of heat pain thresholds, pain rating of supra-thresholds stimulus, mechanical temporal summation, and conditioned pain modulation response were examined. RESULTS The low-anxiety and high-anxiety groups exhibited no significant differences in the parasympathetic function and pain perception parameters. Assessment of the associations revealed that in the high-anxiety group, higher mean ratings of the tonic heat pain stimulus were significantly correlated with higher rMSSD (r2 = 0.358, P = 0.019), but this was not found for the low-anxiety group (P = 0.282). In addition, in the high-anxiety group, efficient conditioned pain modulation response was correlated with higher deep breathing ratio (r2 = 0.363, P = 0.023); however, in the low-anxiety group, the correlation did not reach significance (P = 0.109). CONCLUSIONS This study demonstrates the role of anxiety level on the relationships between parasympathetic function and pain perception. We suggest that a situation of high anxiety leads to higher norepinephrine levels that can influence both parasympathetic function and pain perception, thus explaining the significant relationships found between these 2 systems only in subjects with high anxiety.
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Affiliation(s)
- Hadas Nahman-Averbuch
- The Laboratory of Clinical Neurophysiology, the Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Elliot Sprecher
- The Laboratory of Clinical Neurophysiology, the Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Giris Jacob
- Department of Internal Medicine, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - David Yarnitsky
- The Laboratory of Clinical Neurophysiology, the Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel.,Department of Neurology, Rambam Medical Center, Haifa, Israel
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Granovsky Y, Miller-Barmak A, Goldstein O, Sprecher E, Yarnitsky D. CPM Test-Retest Reliability: "Standard" vs "Single Test-Stimulus" Protocols. PAIN MEDICINE 2016; 17:521-529. [PMID: 26272736 DOI: 10.1111/pme.12868] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVES Assessment of pain inhibitory mechanisms using conditioned pain modulation (CPM) is relevant clinically in prediction of pain and analgesic efficacy. Our objective is to provide necessary estimates of intersession CPM reliability, to enable transformation of the CPM paradigm into a clinical tool. DESIGN Two cohorts of young healthy subjects (N = 65) participated in two dual-session studies. In Study I, a Bath-Thermode CPM protocol was used, with hot water immersion and contact heat as conditioning- and test-stimuli, respectively, in a classical parallel CPM design introducing test-stimulus first, and then the conditioning- and repeated test-stimuli in parallel. Study II consisted of two CPM protocols: 1) Two-Thermodes, one for each of the stimuli, in the same parallel design as above, and 2) single test-stimulus (STS) protocol with a single administration of a contact heat test-stimulus, partially overlapped in time by a remote shorter contact heat as conditioning stimulus. Test-retest reliability was assessed within 3-7 days. RESULTS The STS-CPM had superior reliability intraclass correlation (ICC2 ,: 1 = 0.59) over Bath-Thermode (ICC2 ,: 1 = 0.34) or Two-Thermodes (ICC2 ,: 1 = 0.21) protocols. The hand immersion conditioning pain had higher reliability than thermode pain (ICC2 ,: 1 = 0.76 vs ICC2 ,: 1 = 0.16). Conditioned test-stimulus pain scores were of good (ICC2 ,: 1 = 0.62) or fair (ICC2 ,: 1 = 0.43) reliability for the Bath-Thermode and the STS, respectively, but not for the Two-Thermodes protocol (ICC2 ,: 1 = 0.20). CONCLUSIONS The newly developed STS-CPM paradigm was more reliable than other CPM protocols tested here, and should be further investigated for its clinical relevance. It appears that large contact size of the conditioning-stimulus and use of single rather than dual test-stimulus pain contribute to augmentation of CPM reliability.
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Affiliation(s)
- Yelena Granovsky
- *Department of Neurology, Rambam Health Care Campus .,The Laboratory of Clinical Neurophysiology, Technion Faculty of Medicine, Haifa, Israel
| | - Adi Miller-Barmak
- The Laboratory of Clinical Neurophysiology, Technion Faculty of Medicine, Haifa, Israel
| | - Oren Goldstein
- The Laboratory of Clinical Neurophysiology, Technion Faculty of Medicine, Haifa, Israel
| | - Elliot Sprecher
- *Department of Neurology, Rambam Health Care Campus.,The Laboratory of Clinical Neurophysiology, Technion Faculty of Medicine, Haifa, Israel
| | - David Yarnitsky
- *Department of Neurology, Rambam Health Care Campus.,The Laboratory of Clinical Neurophysiology, Technion Faculty of Medicine, Haifa, Israel
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A Longitudinal Study to Evaluate Pregnancy-Induced Endogenous Analgesia and Pain Modulation. Reg Anesth Pain Med 2016; 41:175-80. [DOI: 10.1097/aap.0000000000000359] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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28
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Physical activity, pain responses to heat stimuli, and conditioned pain modulation in postmenopausal women. Menopause 2015; 22:816-25. [DOI: 10.1097/gme.0000000000000398] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Hermans L, Van Oosterwijck J, Goubert D, Goudman L, Crombez G, Calders P, Meeus M. Inventory of Personal Factors Influencing Conditioned Pain Modulation in Healthy People: A Systematic Literature Review. Pain Pract 2015; 16:758-69. [DOI: 10.1111/papr.12305] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 02/09/2015] [Indexed: 01/19/2023]
Affiliation(s)
- Linda Hermans
- Department of Rehabilitation Sciences and Physiotherapy; Faculty of Medicine and Health Sciences; Ghent University; Ghent Belgium
- Pain in Motion Research Group; Belgium
| | - Jessica Van Oosterwijck
- Department of Rehabilitation Sciences and Physiotherapy; Faculty of Medicine and Health Sciences; Ghent University; Ghent Belgium
- Pain in Motion Research Group; Belgium
| | - Dorien Goubert
- Department of Rehabilitation Sciences and Physiotherapy; Faculty of Medicine and Health Sciences; Ghent University; Ghent Belgium
- Pain in Motion Research Group; Belgium
| | - Lisa Goudman
- Department of Rehabilitation Sciences and Physiotherapy; Faculty of Medicine and Health Sciences; Ghent University; Ghent Belgium
| | - Geert Crombez
- Department of Experimental Clinical and Health Psychology; Ghent University; Ghent Belgium
| | - Patrick Calders
- Department of Rehabilitation Sciences and Physiotherapy; Faculty of Medicine and Health Sciences; Ghent University; Ghent Belgium
| | - Mira Meeus
- Department of Rehabilitation Sciences and Physiotherapy; Faculty of Medicine and Health Sciences; Ghent University; Ghent Belgium
- Pain in Motion Research Group; Belgium
- Department of Rehabilitation Sciences and Physiotherapy; Faculty of Medicine and Health Sciences; University of Antwerp; Antwerp Belgium
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30
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Bernaba M, Johnson KA, Kong JT, Mackey S. Conditioned pain modulation is minimally influenced by cognitive evaluation or imagery of the conditioning stimulus. J Pain Res 2014; 7:689-97. [PMID: 25473310 PMCID: PMC4251756 DOI: 10.2147/jpr.s65607] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Conditioned pain modulation (CPM) is an experimental approach for probing endogenous analgesia by which one painful stimulus (the conditioning stimulus) may inhibit the perceived pain of a subsequent stimulus (the test stimulus). Animal studies suggest that CPM is mediated by a spino-bulbo-spinal loop using objective measures such as neuronal firing. In humans, pain ratings are often used as the end point. Because pain self-reports are subject to cognitive influences, we tested whether cognitive factors would impact on CPM results in healthy humans. METHODS We conducted a within-subject, crossover study of healthy adults to determine the extent to which CPM is affected by 1) threatening and reassuring evaluation and 2) imagery alone of a cold conditioning stimulus. We used a heat stimulus individualized to 5/10 on a visual analog scale as the testing stimulus and computed the magnitude of CPM by subtracting the postconditioning rating from the baseline pain rating of the heat stimulus. RESULTS We found that although evaluation can increase the pain rating of the conditioning stimulus, it did not significantly alter the magnitude of CPM. We also found that imagery of cold pain alone did not result in statistically significant CPM effect. CONCLUSION Our results suggest that CPM is primarily dependent on sensory input, and that the cortical processes of evaluation and imagery have little impact on CPM. These findings lend support for CPM as a useful tool for probing endogenous analgesia through subcortical mechanisms.
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Affiliation(s)
- Mario Bernaba
- Stanford Systems Neuroscience and Pain Laboratory, Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Kevin A Johnson
- Stanford Systems Neuroscience and Pain Laboratory, Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Jiang-Ti Kong
- Stanford Systems Neuroscience and Pain Laboratory, Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Sean Mackey
- Stanford Systems Neuroscience and Pain Laboratory, Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA
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Biurrun Manresa JA, Fritsche R, Vuilleumier PH, Oehler C, Mørch CD, Arendt-Nielsen L, Andersen OK, Curatolo M. Is the conditioned pain modulation paradigm reliable? A test-retest assessment using the nociceptive withdrawal reflex. PLoS One 2014; 9:e100241. [PMID: 24950186 PMCID: PMC4065000 DOI: 10.1371/journal.pone.0100241] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 05/24/2014] [Indexed: 11/18/2022] Open
Abstract
The aim of this study was to determine the reliability of the conditioned pain modulation (CPM) paradigm assessed by an objective electrophysiological method, the nociceptive withdrawal reflex (NWR), and psychophysical measures, using hypothetical sample sizes for future studies as analytical goals. Thirty-four healthy volunteers participated in two identical experimental sessions, separated by 1 to 3 weeks. In each session, the cold pressor test (CPT) was used to induce CPM, and the NWR thresholds, electrical pain detection thresholds and pain intensity ratings after suprathreshold electrical stimulation were assessed before and during CPT. CPM was consistently detected by all methods, and the electrophysiological measures did not introduce additional variation to the assessment. In particular, 99% of the trials resulted in higher NWR thresholds during CPT, with an average increase of 3.4 mA (p<0.001). Similarly, 96% of the trials resulted in higher electrical pain detection thresholds during CPT, with an average increase of 2.2 mA (p<0.001). Pain intensity ratings after suprathreshold electrical stimulation were reduced during CPT in 84% of the trials, displaying an average decrease of 1.5 points in a numeric rating scale (p<0.001). Under these experimental conditions, CPM reliability was acceptable for all assessment methods in terms of sample sizes for potential experiments. The presented results are encouraging with regards to the use of the CPM as an assessment tool in experimental and clinical pain. Trial registration: Clinical Trials.gov NCT01636440.
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Affiliation(s)
- José A. Biurrun Manresa
- Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Raphael Fritsche
- University Department of Anaesthesiology and Pain Therapy, Inselspital, Bern, Switzerland
| | - Pascal H. Vuilleumier
- Department of Anaesthesiology and Pain Medicine, University of Washington, Seattle, United States of America
| | - Carmen Oehler
- University Department of Anaesthesiology and Pain Therapy, Inselspital, Bern, Switzerland
| | - Carsten D. Mørch
- Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Lars Arendt-Nielsen
- Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Ole K. Andersen
- Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Michele Curatolo
- Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
- Department of Anaesthesiology and Pain Medicine, University of Washington, Seattle, United States of America
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