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Pain Jan 2023Processing spatially distributed nociceptive information is critical for survival. The conditioned pain modulation (CPM) response has become a common psychophysical test... (Review)
Review
Processing spatially distributed nociceptive information is critical for survival. The conditioned pain modulation (CPM) response has become a common psychophysical test to examine pain modulation capabilities related to spatial filtering of nociceptive information. Neuroimaging studies have been conducted to elucidate the neural mechanisms underlying the CPM response in health and chronic pain states, yet their findings have not been critically reviewed and synthesized before. This narrative review presents a simplified overview of MRI methodology in relation to CPM assessments and summarizes the findings of neuroimaging studies on the CPM response. The summary includes functional MRI studies assessing CPM responses during scanning as well as functional and structural MRI studies correlating indices with CPM responses assessed outside of the scanner. The findings are discussed in relation to the suggested mechanisms for the CPM response. A better understanding of neural mechanisms underlying spatial processing of nociceptive information could advance both pain research and clinical use of the CPM response as a marker or a treatment target.
Topics: Humans; Chronic Pain; Pain Measurement; Neuroimaging; Magnetic Resonance Imaging; Physical Examination; Pain Threshold
PubMed: 36017881
DOI: 10.1097/j.pain.0000000000002716 -
International Journal of Environmental... Feb 2022Differences in pain perception in athletes have recently been highlighted in the literature.
BACKGROUND
Differences in pain perception in athletes have recently been highlighted in the literature.
OBJECTIVES
To compare gender ratings of perceived pain in athletes with low and high agonistic experiences (N = 200) using the Cold Pressor Test (CPT).
METHODS
A three-way repeated measures ANOVA to assess both the effects of the athletes' gender and lower vs. higher agonistic experiences in the intensity of perceived pain at the beginning of the cold box hand immersion (L) and after a 90 s interval (L).
RESULTS
There was a statistically significant interaction effect between the level of the agonistic experience and gender in the two moments: < 0.001; η = 0.266; F(1,49) = 9.771. Simple main effects analysis showed a significative difference for females at L: F(1,99) = 93.567, < 0.025, partial η = 0.302) and for males at L: F(1,99) = 173.420, < 0.025, partial η = 0.666. At the initial moment of CPT, the female athletes showed significantly higher perceived intensity than males, regardless of their experience level. After a 90 s interval, a significantly lower pain perception effect associated with the increased competitive experience of male athletes was observed. Female athletes did not appear to benefit from the experience effect on their pain tolerance.
CONCLUSIONS
The study confirmed a significant difference in pain perception associated with the athletes' gender and agonistic experience. Separate explanations related to the pattern of pain inhibition and the acquired reduction in pain sensitivity are reported.
Topics: Athletes; Cold Temperature; Female; Humans; Male; Pain; Pain Measurement; Pain Perception; Pain Threshold
PubMed: 35206523
DOI: 10.3390/ijerph19042336 -
PloS One 2014The effect of acupuncture on sensory perception has never been systematically reviewed; although, studies on acupuncture mechanisms are frequently based on the idea that... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The effect of acupuncture on sensory perception has never been systematically reviewed; although, studies on acupuncture mechanisms are frequently based on the idea that changes in sensory thresholds reflect its effect on the nervous system.
METHODS
Pubmed, EMBASE and Scopus were screened for studies investigating the effect of acupuncture on thermal or mechanical detection or pain thresholds in humans published in English or German. A meta-analysis of high quality studies was performed.
RESULTS
Out of 3007 identified articles 85 were included. Sixty five studies showed that acupuncture affects at least one sensory threshold. Most studies assessed the pressure pain threshold of which 80% reported an increase after acupuncture. Significant short- and long-term effects on the pressure pain threshold in pain patients were revealed by two meta-analyses including four and two high quality studies, respectively. In over 60% of studies, acupuncture reduced sensitivity to noxious thermal stimuli, but measuring methods might influence results. Few but consistent data indicate that acupuncture reduces pin-prick like pain but not mechanical detection. Results on thermal detection are heterogeneous. Sensory threshold changes were equally frequent reported after manual acupuncture as after electroacupuncture. Among 48 sham-controlled studies, 25 showed stronger effects on sensory thresholds through verum than through sham acupuncture, but in 9 studies significant threshold changes were also observed after sham acupuncture. Overall, there is a lack of high quality acupuncture studies applying comprehensive assessments of sensory perception.
CONCLUSIONS
Our findings indicate that acupuncture affects sensory perception. Results are most compelling for the pressure pain threshold, especially in pain conditions associated with tenderness. Sham acupuncture can also cause such effects. Future studies should incorporate comprehensive, standardized assessments of sensory profiles in order to fully characterize its effect on sensory perception and to explore the predictive value of sensory profiles for the effectiveness of acupuncture.
Topics: Acupuncture Therapy; Databases, Bibliographic; Humans; Pain Threshold
PubMed: 25502787
DOI: 10.1371/journal.pone.0113731 -
PloS One 2017To investigate whether pressure pain threshold (PPT), determined by pressure algometry, can be used as an objective measure of perceived stress and job strain.
OBJECTIVE
To investigate whether pressure pain threshold (PPT), determined by pressure algometry, can be used as an objective measure of perceived stress and job strain.
METHODS
We used cross-sectional base line data collected during 1994 to 1995 within the Project on Research and Intervention in Monotonous work (PRIM), which included 3123 employees from a variety of Danish companies. Questionnaire data included 18 items on stress symptoms, 23 items from the Karasek scale on job strain, and information on discomfort in specified anatomical regions was also collected. Clinical examinations included pressure pain algometry measurements of PPT on the trapezius and supraspinatus muscles and the tibia. Associations of stress symptoms and job strain with PPT of each site was analyzed for men and women separately with adjustment for age body mass index, and discomfort in the anatomical region closest to the point of pressure algometry using multivariable linear regression.
RESULTS
We found significant inverse associations between perceived stress and PPT in both genders in models adjusting for age and body mass index: the higher level of perceived stress, the lower the threshold. For job strain, associations were weaker and only present in men. In men all associations were attenuated when adjusting for reported discomfort in regions close to the site of pressure algometry. The distributions of PPT among stressed and non-stressed persons were strongly overlapping.
CONCLUSIONS
Despite significant associations between perceived stress and PPT, the discriminative capability of PPT to distinguish individuals with and without stress is low. PPT measured by pressure algometry seems not applicable as a diagnostic tool of a state of mental stress.
Topics: Adult; Female; Humans; Male; Muscles; Pain Threshold; Pressure; Self Report; Stress, Psychological; Tibia; Work
PubMed: 28052089
DOI: 10.1371/journal.pone.0167257 -
Biological Psychology May 2022Poor sleep quality is often comorbid with chronic pain. Research has also shown that poor and disrupted sleep may increase risk for chronic pain by promoting...
Poor sleep quality is often comorbid with chronic pain. Research has also shown that poor and disrupted sleep may increase risk for chronic pain by promoting pronociceptive processes. This could occur through disrupted emotional modulation of pain since poor sleep can impact emotional experience and emotional experience modulates pain and nociception. To assess the pain system, nociceptive flexion reflexes (spinal level), pain-evoked potentials (supraspinal level), and perceived pain were recorded during an emotional picture-viewing task in which 37 healthy individuals received painful electric stimulations. The Pittsburgh Sleep Quality Index assessed sleep quality. Individuals with poor sleep quality were unable to inhibit signals at the spinal level in response to positive pictures, whereas emotional modulation of supraspinal nociception and pain perception remained unaffected by sleep quality. This suggests poor sleep quality may promote pronociception by impairing descending, emotional modulation of spinal nociception.
Topics: Chronic Pain; Electric Stimulation; Emotions; Humans; Nociception; Pain Measurement; Pain Threshold; Sleep Quality
PubMed: 35569574
DOI: 10.1016/j.biopsycho.2022.108352 -
Scientific Reports May 2023Recent research on transcutaneous electrical stimulation has shown that inhibiting nerve conduction with a kilohertz frequency is both effective and safe. This study...
Recent research on transcutaneous electrical stimulation has shown that inhibiting nerve conduction with a kilohertz frequency is both effective and safe. This study primarily aims to demonstrate the hypoalgesic effect on the tibial nerve using transcutaneous interferential-current nerve inhibition (TINI), which injects the kilohertz frequency produced by the interferential currents. Additionally, the secondary objective was to compare the analgesic effect and comfort of TINI and transcutaneous electrical nerve stimulation (TENS). Thirty-one healthy adults participated in this cross-over repeated measures study. The washout period was set to 24 h or more. Stimulus intensity was set just below the pain threshold level. TINI and TENS were applied for 20 min each. The ankle passive dorsiflexion range of motion, pressure pain threshold (PPT), and tactile threshold were measured at the baseline, pre-test, test (immediately before ceasing intervention), and post-test (30 min after ceasing intervention) sessions. After the interventions, the participants evaluated the level of discomfort for TINI and TENS on a 10 cm visual analog scale (VAS). As the results, PPT significantly increased compared to baseline in test and posttest sessions of TINI, but not in those of TENS. Also, participants reported that TENS was 36% more discomfort than TINI. The hypoalgesic effect was not significantly different between TINI and TENS. In conclusion, we found that TINI inhibited mechanical pain sensitivity and that the inhibitory effect persisted long after electrical stimulation ceased. Our study also shows that TINI provides the hypoalgesic effect more comfortably than TENS.
Topics: Adult; Humans; Transcutaneous Electric Nerve Stimulation; Pain Threshold; Pain; Pain Management; Pain Measurement
PubMed: 37244893
DOI: 10.1038/s41598-023-35489-7 -
The Journal of Manual & Manipulative... Feb 2023Correction of scapular alignment is advocated as a component for alleviating symptoms for patients with neck pain. (Randomized Controlled Trial)
Randomized Controlled Trial
Effects of active scapular correction on cervical range of motion, pain, and pressure pain threshold in patients with chronic neck pain and depressed scapula: a randomized controlled trial.
BACKGROUND
Correction of scapular alignment is advocated as a component for alleviating symptoms for patients with neck pain.
OBJECTIVE
The study aimed to examine the effect of active scapular correction on cervical range of motion (ROM), pain, and pressure pain threshold (PPT) in patients with chronic neck pain with depressed scapula.
METHODS
A randomized control trial research design was conducted. Twenty-eight participants with chronic neck pain and depressed scapula were randomly assigned to either the intervention (n = 14) or control (n = 14) group. Active cervical rotation ROM, pain at maximum cervical rotation, and PPT over the upper trapezius muscle region were measured at baseline and post active scapular correction.
RESULTS
The participants in the intervention group showed significantly greater active cervical rotation ROM and less pain at maximum cervical rotation than the control group, both on the ipsilateral ( < 0.01) and contralateral ( < 0.05) sides of the depressed scapula. No significant difference in PPT between the groups was demonstrated ( = 0.194).
CONCLUSION
Active scapular correction intervention resulted in an immediate increase in active cervical rotation ROM and a decrease in neck pain at maximum cervical rotation.
Topics: Humans; Pain Threshold; Neck Pain; Chronic Pain; Range of Motion, Articular; Scapula
PubMed: 35588354
DOI: 10.1080/10669817.2022.2077515 -
Pain Medicine (Malden, Mass.) Aug 2022To assess the potential relationship of demographic (age, gender, body mass index, height, weight), clinical (affected side, duration of symptoms, health-related quality...
OBJECTIVE
To assess the potential relationship of demographic (age, gender, body mass index, height, weight), clinical (affected side, duration of symptoms, health-related quality of life), psychological (depressive levels), or neurophysiological (pressure pain sensitivity and number of trigger points) variables with foot function and pain intensity in patients with unilateral plantar heel pain (PHP).
METHODS
Fifty-four patients with PHP (48% females) were recruited. Data on demographics, months with pain, time in standing position, depression, pressure pain thresholds (PPTs), number of trigger points, health-related quality of life, function, and pain intensity were collected. A multivariable correlation analysis was performed to determine the associations among the variables, and a regression analysis was conducted to explain the variance in function and pain intensity.
RESULTS
Pain intensity was negatively correlated with symptom duration and calcaneus bone PPT and positively associated with gender, time in standing position, and number of trigger points. Function was negatively correlated with PPTs on the calcaneus bone, the flexor digitorum brevis muscle, and the abductor hallucis muscle and with quality of life and was positively correlated with age, gender, and depressive levels. Stepwise regression analyses revealed that 60.8% of pain intensity was explained by female gender, calcaneus PPTs, time in a standing position, and function. Furthermore, gender, quality of life, age, depressive levels, and calcaneus bone PPTs explained 52.4% of function variance.
CONCLUSIONS
This study found that demographic, clinical, psychological, and neurophysiological variables can mutually interact to affect function and pain intensity in patients with unilateral PHP. These findings could guide clinicians in the identification, prevention, and treatment of PHP risk factors.
Topics: Female; Heel; Humans; Male; Pain; Pain Measurement; Pain Threshold; Quality of Life
PubMed: 35089360
DOI: 10.1093/pm/pnac018 -
Physical Therapy Mar 2021Evidence suggests altered pronociceptive and antinociceptive mechanisms in many chronic pain conditions. Knowledge about these mechanisms in nonspecific chronic neck... (Comparative Study)
Comparative Study
OBJECTIVE
Evidence suggests altered pronociceptive and antinociceptive mechanisms in many chronic pain conditions. Knowledge about these mechanisms in nonspecific chronic neck pain (NSNP) would improve understanding of the causes and the design of more effective treatments. Pressure pain threshold (PPT) is often used to assess presence of altered nociceptive processing in NSNP; however, its usefulness to detect this is yet to be established. The purpose of this study was to determine the functional status of temporal summation of second pain (TSSP) and conditioned pain modulation (CPM) in NSNP and to characterize the association of both measures with PPT and clinical features of NSNP.
METHODS
Thirty-two participants with NSNP (mean [SD] age = 44 [11] years; 27 female) and 32 age- and sex-matched healthy controls were recruited. TSSP was assessed using an electrical stimulus at the dorsum of the hand, and CPM was evaluated with the Cold Pressor Test. PPT was assessed bilaterally at the neck and tibialis anterior muscles.
RESULTS
Participants with NSNP showed greater TSPP (mean difference = 0.23; 95% CI = 0.46-0.01; Cohen d = 0.51) and lower CPM (mean difference = 19.44; 95% CI = 10.42-28.46; Cohen d = 1.09). Pooled data from all participants showed lower PPTs at the neck than the tibialis anterior. However, PPT measures did not differ between groups at either location. PPT measures were not correlated with CPM and TSP.
CONCLUSION
NSNP is associated with enhanced pronociceptive and impaired antinociceptive mechanisms, which may explain long-lasting pain and failure of some treatments to resolve symptoms. However, due to the observational nature of this study, a clear cause-effect relationship cannot be established. Normal PPT values in the clinic should not be interpreted as absence of altered nociceptive processing.
IMPACT
This study fills in some gaps in knowledge. Changes in central nociceptive processing may explain persistent and recurrent symptoms in NSNP and failure of treatments to obtain long-lasting relief. Further research is required to ascertain if TSSP and CPM assessment in the clinic may help predict physical therapy treatment outcome. Whether symptomatic relief with physical therapy is mediated by an improvement in TSSP and CPM should also be explored. PPTs were unaltered in participants with NSNP despite evidence of impairment in the central pain modulatory systems. Normal PPTs should not be interpreted as evidence of unaltered central pain-related processing.
Topics: Adult; Case-Control Studies; Central Nervous System Sensitization; Chronic Pain; Disability Evaluation; Female; Humans; Male; Middle Aged; Neck Pain; Pain Measurement; Pain Threshold
PubMed: 33351923
DOI: 10.1093/ptj/pzaa223 -
Physiological Research Dec 2017In recent years, epidemiological data has shown an increasing number of young people who deliberately self-injure. There have also been parallel increases in the number...
In recent years, epidemiological data has shown an increasing number of young people who deliberately self-injure. There have also been parallel increases in the number of people with tattoos and those who voluntarily undergo painful procedures associated with piercing, scarification, and tattooing. People with self-injury behaviors often say that they do not feel the pain. However, there is no information regarding pain perception in those that visit tattoo parlors and piercing studios compared to those who don't. The aim of this study was to compare nociceptive sensitivity in four groups of subjects (n=105, mean age 26 years, 48 women and 57 men) with different motivations to experience pain (i.e., with and without multiple body modifications) in two different situations; (1) in controlled, emotionally neutral conditions, and (2) at a "Hell Party" (HP), an event organized by a piercing and tattoo parlor, with a main event featuring a public demonstration of painful techniques (burn scars, hanging on hooks, etc.). Pain thresholds of the fingers of the hand were measured using a thermal stimulator and mechanical algometer. In HP participants, information about alcohol intake, self-harming behavior, and psychiatric history were used in the analysis as intervening variables. Individuals with body modifications as well as without body modifications had higher thermal pain thresholds at Hell Party, compared to thresholds measured at control neutral conditions. No such differences were found relative to mechanical pain thresholds. Increased pain threshold in all HP participants, irrespectively of body modification, cannot be simply explained by a decrease in the sensory component of pain; instead, we found that the environment significantly influenced the cognitive and affective component of pain.
Topics: Adolescent; Adult; Body Piercing; Female; Hot Temperature; Humans; Male; Pain Measurement; Pain Threshold; Tattooing; Young Adult
PubMed: 29355376
DOI: 10.33549/physiolres.933804