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Pain Research & Management 2023Pain sensitivity decreases following isometric exercise. It is not clear whether this exercise-induced hypoalgesia (EIH) occurs to the same extent in men and women. It...
OBJECTIVE
Pain sensitivity decreases following isometric exercise. It is not clear whether this exercise-induced hypoalgesia (EIH) occurs to the same extent in men and women. It is also unclear if the effect is systemic or local to the exercised musculature. The aim of our study was to investigate whether fatiguing isometric exercise of the spinal and hip extensors would result in increased pressure pain threshold (PPT) at sites local to and remote from the exercised muscles in healthy men and women and whether there is a relationship between central sensitization, psychosocial factors, and PPT.
SUBJECTS
35 healthy adults (age 27.1 ± 4.5 years, 22 women).
METHODS
This was a within-subjects cohort study. Participants completed questionnaires quantifying central sensitization, pain catastrophizing, sleepiness/insomnia, anxiety, and depression. PPT was assessed at the lumbar and thoracic paraspinals, hamstrings, gastrocnemius, wrist, and third digit before and immediately after participants performed the Biering-Sorensen test to failure.
RESULTS
PPT increased postexercise in the thoracic paraspinals, hamstrings, and gastrocnemius in men and women and in the lumbar paraspinals in men only but did not change at the wrist and digit sites. A lower average PPT at baseline was associated with a higher central sensitization scores. A greater increase in average PPT postfatigue was significantly associated with higher average PPT at baseline.
CONCLUSIONS
Exercise-induced hypoalgesia occurs at sites overlying the muscles involved in fatiguing exercise, but not at remote sites, and is more evident in males than females. The magnitude of EIH depends upon baseline PPT. Even in healthy individuals, greater central sensitization is associated with lower baseline PPT.
Topics: Male; Adult; Humans; Female; Young Adult; Pain Threshold; Muscle Fatigue; Cohort Studies; Pain Measurement; Isometric Contraction; Pain; Hypesthesia
PubMed: 36741677
DOI: 10.1155/2023/7336477 -
Physical Therapy in Sport : Official... Sep 2023Exercise-induced hypoalgesia refers to a reduction in pain sensitivity following a single bout of exercise, which has been shown to be diminished or impaired with aging... (Review)
Review
Exercise-induced hypoalgesia refers to a reduction in pain sensitivity following a single bout of exercise, which has been shown to be diminished or impaired with aging and chronic pain. Exercise training (repeated bouts of exercise over time) is often recommended as a non-pharmacological treatment for chronic pain and age-related functional declines. However, whether exercise training can augment the exercise-induced hypoalgesia has not been well studied. The purpose of this paper is to 1) provide an overview of the existing literature investigating the effect of exercise training on the magnitude of exercise-induced hypoalgesia, and 2) discuss potential underlying mechanisms as well as considerations for future research. Given the paucity of randomized controlled trials in this area, the effects of exercise training on exercise-induced hypoalgesia are still unclear. Several potential mechanisms have been proposed to explain the impaired exercise-induced hypoalgesia in chronic pain and older individuals (e.g., endogenous opioid, cardiovascular, and immune system). Exercise training appears to induce physiological changes in those systems, however, further investigations are necessary to test whether this will lead to improved exercise-induced hypoalgesia. Future research should consider including a time- and age-matched non-training group and utilizing the same exercise protocol for testing exercise-induced hypoalgesia across intervention groups.
Topics: Humans; Chronic Pain; Pain Threshold; Exercise; Research Design
PubMed: 37527566
DOI: 10.1016/j.ptsp.2023.07.005 -
Pain Medicine (Malden, Mass.) Mar 2022Conditioned pain modulation (CPM) can discriminate between healthy and chronic pain patients. However, its relationship with neurophysiological pain mechanisms is poorly...
UNLABELLED
Conditioned pain modulation (CPM) can discriminate between healthy and chronic pain patients. However, its relationship with neurophysiological pain mechanisms is poorly understood. Brain oscillations measured by electroencephalography (EEG) might help gain insight into this complex relationship.
OBJECTIVE
To investigate the relationship between CPM response and self-reported pain intensity in non-specific chronic low back pain (NSCLBP) and explore respective EEG signatures associated to these mechanisms.
DESIGN
Cross-sectional analysis.
PARTICIPANTS
Thirty NSCLBP patients participated.
METHODS
Self-reported low back pain, questionnaires, mood scales, CPM (static and dynamic quantitative sensory tests), and resting surface EEG data were collected and analyzed. Linear regression models were used for statistical analysis.
RESULTS
CPM was not significantly correlated with self-reported pain intensity scores. Relative power of EEG in the beta and high beta bands as recorded from the frontal, central, and parietal cortical areas were significantly associated with CPM. EEG relative power at delta and theta bands as recorded from the central area were significantly correlated with self-reported pain intensity scores while controlling for self-reported depression.
CONCLUSIONS
Faster EEG frequencies recorded from pain perception areas may provide a signature of a potential cortical compensation caused by chronic pain states. Slower EEG frequencies may have a critical role in abnormal pain processing.
Topics: Chronic Pain; Cross-Sectional Studies; Electroencephalography; Humans; Low Back Pain; Pain Perception; Pain Threshold
PubMed: 34633449
DOI: 10.1093/pm/pnab293 -
BJOG : An International Journal of... Nov 2022Pelvic pain has been associated with augmented nociceptive processing, but large studies controlling for multiple potential confounding factors are lacking. This study...
OBJECTIVE
Pelvic pain has been associated with augmented nociceptive processing, but large studies controlling for multiple potential confounding factors are lacking. This study investigated the association between pelvic pain bothersomeness and pain sensitivity in young adult women, accounting for potential confounding factors.
DESIGN
Cross-sectional study.
SETTING
Community-dwelling sample.
POPULATION
The Raine Study Gen2-22 year follow-up (n = 475).
MAIN OUTCOME MEASURES
The experience of bothersomeness related to pelvic pain was determined from a question in the Urogenital Distress Inventory short form. Pain sensitivity was measured using pressure pain and cold pain thresholds. Potential confounding factors included ethnicity, marital status, highest level of education, income, waist-hip ratio, level of activity, sleep quality, smoking, comorbidity history, C-reactive protein level, musculoskeletal pain experience and psychological distress.
RESULTS
Three hundred and sixty-two women (76.2%) reported no pelvic pain bothersomeness, 74 (15.6%) reported mild pelvic pain bothersomeness and 39 (8.2%) reported moderate-severe pelvic pain bothersomeness. After adjusting for marital status (and test site), moderate-severe pelvic pain bothersomeness was associated with a lower pressure pain threshold (i.e. greater pressure pain sensitivity) (coefficient -51.46, 95% CI -98.06 to -4.86, p = 0.030). After adjusting for smoking, moderate-severe pelvic pain bothersomeness was also associated with a higher cold pain threshold (i.e. greater cold pain sensitivity) (coefficient 4.35, 95% CI 0.90-7.79, p = 0.014).
CONCLUSIONS
This study suggests augmented nociceptive processing as a contributing factor in pelvic pain bothersomeness for some women. Thorough assessment of women who present clinically with pelvic pain should consider pain sensitivity as a potential contributing factor to their presentation.
Topics: C-Reactive Protein; Cross-Sectional Studies; Female; Humans; Pain Measurement; Pain Threshold; Pelvic Pain; Young Adult
PubMed: 35596698
DOI: 10.1111/1471-0528.17232 -
PloS One 2021To determine the absolute and relative intra-rater within-session test-retest reliability of pressure pain threshold (PPT) and mechanical temporal summation of pain...
OBJECTIVE
To determine the absolute and relative intra-rater within-session test-retest reliability of pressure pain threshold (PPT) and mechanical temporal summation of pain (TSP) at the low back and the forearm in healthy participants and to test the influence of the number and sequence of measurements on reliability metrics.
METHODS
In 24 participants, three PPT and TSP measures were assessed at four sites (2 at the low back, 2 at the forearm) in two blocks of measurements separated by 20 minutes. The standard error of measurement, the minimal detectable change (MDC) and the intraclass correlation coefficient (ICC) were investigated for five different sequences of measurements (e.g. measurement 1, 1-2, 1-2-3).
RESULTS
The MDC for the group (MDCgr) for PPT ranged from 28.71 to 50.56 kPa across the sites tested, whereas MDCgr for TSP varied from 0.33 to 0.57 out of 10 (numeric scale). Almost all ICC showed an excellent relative reliability (between 0.80 and 0.97), except when only the first measurement was considered (moderate). Although minimal differences in absolute PPT reliability were present between the different sequences, in general, using only the first measurement increase measurement error. Three TSP measures reduced the measurement error.
DISCUSSION
We established that two measurements of PPT and three of TSP reduced the measurement error and demonstrated an excellent relative reliability. Our results could be used in future pain research to confirm the presence of true hypo/hyperalgesia for paradigms such as conditioned pain modulation or exercise-induced hypoalgesia, indicated by a change exceeding the measurement variability.
Topics: Adult; Back; Female; Forearm; Healthy Volunteers; Humans; Male; Pain; Pain Measurement; Pain Threshold; Pressure; Young Adult
PubMed: 33434233
DOI: 10.1371/journal.pone.0245278 -
European Journal of Pain (London,... Jul 2015
Topics: Animals; Hindlimb; Low Back Pain; Male; Pain Threshold; Posterior Horn Cells; Stress, Physiological
PubMed: 25940340
DOI: 10.1002/ejp.701 -
Pain Apr 2015
Topics: Back Pain; Chronic Pain; Female; Humans; Male; Pain Threshold; Psychological Trauma
PubMed: 25790449
DOI: 10.1097/j.pain.0000000000000098 -
Odontology Jan 2023This study aimed to evaluate somatosensory function in Chinese patients with trigeminal neuralgia (TN) using a standard quantitative sensory testing (QST) battery and...
This study aimed to evaluate somatosensory function in Chinese patients with trigeminal neuralgia (TN) using a standard quantitative sensory testing (QST) battery and electrophysiological tests consisting of contact heat-evoked potentials (CHEPs) and blink reflex (BR). Twenty patients with TN and 20 sex- and age-matched healthy controls were recruited for this study. A standard QST protocol recommended by the German Research Network on Neuropathic Pain was carried out on the patients' painful and contralateral faces, the controls' right faces, and all participants' right hands. The CHEPs and BR were recorded at the Cz electrode and bilateral lower bellies of the orbicularis oculi, respectively, with thermal stimuli applied to both sides of the patient's face and the control's right face. The cold detection threshold, heat pain threshold, and mechanical pain threshold on the painful face were lower than those of healthy controls (P < 0.05), whereas the cold pain threshold and mechanical detection threshold were higher (P < 0.05) on the painful faces than those of the contralateral faces from patients or healthy controls. Mechanical pain sensitivity was higher in both test sites than in healthy controls (P < 0.05). Significantly longer N latencies (P < 0.05) and lower N-P amplitudes (P < 0.01) were detected in the patients' painful sites than in the contralateral sites and those of healthy controls. Comprehensive somatosensory abnormalities were found in painful facial sites in patients with TN, suggesting disturbances in the processing of somatosensory stimuli. Deficiencies in electrophysiological tests further revealed unilaterally impaired function of the trigeminal pathway in TN patients.
Topics: Humans; Trigeminal Neuralgia; East Asian People; Pain Threshold; Pain Measurement; Asian People
PubMed: 36094685
DOI: 10.1007/s10266-022-00737-1 -
Hua Xi Kou Qiang Yi Xue Za Zhi = Huaxi... Dec 2022This study aimed to investigate whether the microglia in the spinal trigeminal nucleus caudal part (Sp5C) were activated in a rat model of trigeminal neuralgia and to...
OBJECTIVES
This study aimed to investigate whether the microglia in the spinal trigeminal nucleus caudal part (Sp5C) were activated in a rat model of trigeminal neuralgia and to explore whether the activation level of microglia is consistent with maxillofacial pain level.
METHODS
Chronic constriction injury of trigeminal nerve (CCI) was induced by partial ligation of infraorbital nerve (IoN) in rats. The behavioral change of rats observed at D1, D5, D10, D15, and D30 days post-surgery and the change of pain threshold were detected with electronic Von Frey filaments served as an evaluation index of maxillofacial pain. Weight change was measured by weighing. Ionized calcium binding adaptor molecule-1 (Iba-1) expression level of Sp5C at each time point was detected, and three microglia morphological categories were analyzed by immunohistochemical staining.
RESULTS
The changes of behavioral and pain threshold suggested the maxillofacial pain level first increased and then decreased post-surgery in the IoN-CCI group. Both the expressions of Iba-1 and proportion of ameboid morphology in ipsilateral Sp5C increased from D1 and reached their peaks in D10 and D5, respectively. Then, they recovered nearly to the same level with contralateral Sp5C on D30. This trend was consistent with the maxillofacial change.
CONCLUSIONS
The model of trigeminal neuralgia in rats constructed by partial ligation of infraorbital nerve can induce the activation of microglia in Sp5C, and the activation level is consistent with maxillofacial pain, which reached its peak at around D10 post-surgery.
Topics: Rats; Animals; Trigeminal Neuralgia; Rats, Sprague-Dawley; Microglia; Pain Threshold; Pain
PubMed: 36416315
DOI: 10.7518/hxkq.2022.06.003 -
Journal of Oral Rehabilitation Feb 2016Many chronic pain patients are refractory to treatment, which leads to the suspicion that somehow they are not fully effective and probably some mechanism of pain...
Many chronic pain patients are refractory to treatment, which leads to the suspicion that somehow they are not fully effective and probably some mechanism of pain generation and/or maintenance is still unknown. The aim of this cross-sectional study was to provide evidence-based data on pain mechanisms in different types of chronic pain conditions. Eighty women, with 18-65 years old, were included, divided into four groups: myofascial pain of the masticatory muscles (n = 20), fibromyalgia (n = 20), chronic daily headache and healthy volunteers (n = 20). All patients were submitted to quantitative sensory tests: pressure pain threshold, mechanical detection threshold, mechanical pain threshold, ischaemic pain tolerance, cold pain sensitivity, aftersensation, wind-up ratio and conditioned pain modulation. Current perception threshold was also determined (Neurometer CPT/C - Neurotron). Three different zones were evaluated: trigeminal (masseter muscle), cervical and extratrigeminal (thenar eminence). Data were recorded and subjected to statistical analysis (anova, Tukey and Student's t-tests). Masticatory myofascial pain, fibromyalgia and chronic daily headache individuals presented lower pressure pain thresholds than healthy volunteers (P = 0.00). Chronic daily headache individuals had a significantly higher mechanical detection threshold than healthy volunteers (P = 0.01). Individuals of the symptomatic groups showed lower values for mechanical pain threshold and for ischaemic pain tolerance (P = 0.00) than healthy volunteers. The ability to activate the mechanism of endogenous modulation is impaired in women with fibromyalgia and myofascial pain (P = 0.00). These results reinforce evidence of central sensitisation and impaired endogenous modulation system in individuals with myofascial pain, fibromyalgia and chronic daily headache.
Topics: Adolescent; Adult; Aged; Chronic Disease; Cross-Sectional Studies; Female; Fibromyalgia; Headache Disorders; Humans; Masticatory Muscles; Middle Aged; Myofascial Pain Syndromes; Pain Measurement; Pain Threshold; Young Adult
PubMed: 26337788
DOI: 10.1111/joor.12344