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INTRODUCTION: The intensity of pain perceived for the same noxious stimulus is different in different persons, depending on the biological, psychological, and social factors related to the individual. In clinical practice, it is important to know the factors influencing pain perception. The presence of anemia may affect pain perception. METHODS: This study was conducted on 73 female subjects of whom 25 were non-anemic, 24 had mild, and 24 had moderate anemia. Experimental pain was produced by cold pressor task (CPT). Pain response was evaluated in terms of cardiovascular reactivity (CVR - changes in blood pressure and heart rate), and pain sensitivity (PS - pain threshold, pain tolerance, and pain rating). RESULTS: Anemic subjects showed higher CVR to stress. The average increase in systolic blood pressure was 5.28 mm of Hg in non-anemic, compared to 3.25 in mildly anemic and 9.00 mm of Hg in moderately anemic subjects. The average increase in diastolic blood pressure was 2.24 mm of Hg in non-anemic, 2.5 in mildly anemic, and 4.83 mm of Hg in moderately anemic subjects. The average increase in heart rate was 2.88 beats per minute (bpm) in non-anemic, 4.83 in mildly anemic, and 7 bpm in moderately anemic subjects. Pain rating was higher in anemic subjects (average 7.21) compared to the non-anemic subjects (average 6.44). CONCLUSION: CPT-induced pain causes greater cardiovascular reactivity in anemic patients. The average pain rating is higher in anemic subjects.
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BACKGROUND: Sex is an important factor influencing the development and treatment of chronic pain, but the extent of its influence is still unclear. Other demographic factors as well as nonpharmacological interventions might influence pain sensitivity differently in men and women. OBJECTIVE: In this study, we aimed to investigate the influence of sex and other demographic, lifestyle, behavioral, clinical, and environmental factors on pain sensitivity in the Dutch population. Different films were used to investigate how they would impact pain sensitivity and what influence sex and other variables have on the effect of this simple intervention. METHODS: We performed a study consisting of 2 parts: (1) a cross-sectional research to investigate pain sensitivity differences between men and women and the influence of other demographic variables on the pain sensitivity in a Dutch cohort and (2) an internet intervention study to determine whether a short film could skew pain sensitivity. RESULTS: All respondents filled in a web-based demographic questionnaire and were randomized into 4 groups. The control group filled in the Pain Sensitivity Questionnaire without watching a preliminary film. A cross-sectional analysis was performed in the control group (n=1746). The other 3 groups watched short films: one group watched a film with scenes of nature (n=2650), another group watched a film on laughing people (n=2735), and the last group watched a film on physically painful events (n=2708). Immediately after the film viewing, participants were directed to the Pain Sensitivity Questionnaire to measure their pain sensitivity. The Pain Sensitivity Questionnaire score was stated as a mean per question on the numeric rating scale from 0-1. The cross-sectional study revealed no significant differences between men and women but showed male-female differences in the Pain Sensitivity Questionnaire when specific background factors were present. Watching a short film had a positive impact on the pain sensitivity of the respondents who had chronic pain, with a higher effect observed in female respondents. CONCLUSIONS: Scientists performing pain research need to account for factors that can influence the outcome of their study and be aware that these factors can be sex-dependent, and pain sensitivity should be analyzed accordingly. Even relatively small interventions such as watching a film can impact pain sensitivity, especially in respondents with current chronic pain. This effect can vary as well when different background factors are present. Our findings warrant further explorations of the possibilities that simple interventions bring for patients in personalized medicine. TRIAL REGISTRATION: Landelijk Trial Register NTR-new NL8182; https://onderzoekmetmensen.nl/en/trial/29537.
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Internet , Humanos , Femenino , Estudios Transversales , Masculino , Países Bajos , Adulto , Persona de Mediana Edad , Estudios de Cohortes , Encuestas y Cuestionarios , Caracteres Sexuales , Umbral del Dolor , Dolor Crónico/terapia , Dolor/psicología , Factores Sexuales , AncianoRESUMEN
Homeostasis models posit that nonsuicidal self-injury (NSSI) serves, in part, to upregulate the endogenous opioid system in order to compensate for an opioid deficiency. A few studies have demonstrated lower basal levels of beta-endorphin (BE), an endogenous opioid, in individuals with NSSI. However, longitudinal studies are missing. Hence, the present study aimed to investigate the longitudinal associations between NSSI, comorbid psychopathology (i.e., borderline personality disorder and depressive symptoms), pain sensitivity and basal BE levels in adolescents with NSSI. N = 53 adolescents with NSSI disorder undergoing specialized treatment participated in baseline and one-year follow-up assessments. BE was measured in plasma; pain sensitivity was assessed with a heat pain stimulation paradigm. Associations between BE and change in NSSI, borderline personality disorder and depressive symptoms as well as pain sensitivity were examined using negative binomial and linear regression analyses. We found that an increase in basal BE was significantly associated with a decrease in depressive symptoms. No associations between BE and NSSI, borderline personality disorder symptoms or pain sensitivity were observed. Our findings may confirm a role of plasma BE in the etiology of depressive symptoms but challenge current models of endogenous opioid homeostasis in NSSI.
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INTRODUCTION: The Pain Sensitivity Questionnaire (PSQ) was developed to assess general pain sensitivity. OBJECTIVE: This study aimed to validate the Greek version of PSQ. METHODS: The questionnaire was translated into Greek (PSQ-GR) and piloted in a small sample of patients with chronic pain (n = 35). A total of 146 chronic pain patients and healthy volunteers completed the PSQ-GR, the Pain Catastrophizing Scale (PCS), Hospital Anxiety and Depression Scale (HADS) and Central Sensitization Inventory (CSI). To evaluate the test-retest reliability, 36 volunteers completed the PSQ-GR twice over 7 ± 2 days. RESULTS: Internal consistency was excellent (Cronbach's alpha 0.90-0.96) for PSQ-total, PSQ-minor, and PSQ-moderate. The Intraclass Correlation Coefficient was estimated at 0.90-0.96 for PSQ-total, PSQ-minor and PSQ-moderate and the SEM was 0.59-0.90 for PSQ-total, PSQ-minor and PSQ-moderate approximately. The smallest detectable change was 0.48 for PSQ-total, 0.47 for PSQ-minor and 0.44 for PSQ-moderate. Positive and significant correlations were observed between PSQ-GR and HADS (r = 0.38, p < 0.01), PCS (r = 0.41, p < 0.01) and CSI (r = 0.30, p < 0.01). Statistically significant differences in PSQ-GR scores were identified between the healthy volunteers and the chronic pain patients. CONCLUSION: The PSQ-GR is a reliable and valid tool that can assess pain sensitivity in healthy individuals and chronic musculoskeletal pain patients.
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Dolor Crónico , Comparación Transcultural , Dimensión del Dolor , Psicometría , Humanos , Masculino , Femenino , Reproducibilidad de los Resultados , Persona de Mediana Edad , Grecia , Encuestas y Cuestionarios , Dolor Crónico/diagnóstico , Adulto , Traducciones , Umbral del Dolor/fisiología , Catastrofización , AncianoRESUMEN
OBJECTIVE: To examine associations of vibration sensitivity and pressure pain sensitivity with knee osteoarthritis (OA) outcomes across sex and race, which may relate to known sex and race disparities in clinical outcomes. DESIGN: Data were from the 2013-2015 visit of the Johnston County Osteoarthritis Project. Exposures were vibration perception threshold (VPT) measured at the bilateral medial femoral condyle (MFC) and first metatarsophalangeal joint (MTP), and pressure pain threshold (PPT) measured at the bilateral upper trapezius. Outcomes were knee pain severity and presence of knee symptoms, radiographic knee OA, and symptomatic knee OA in each knee. Cross-sectional associations of the exposures with the outcomes were examined using logistic regression models, overall and separately by sex and race. RESULTS: In the VPT and PPT analyses, 851 and 862 participants (mean age 71 years, 68% female, 33% Black, body mass index 31 kg/m2) and 1585 and 1660 knees were included, respectively. Higher VPT (lower vibration sensitivity) at the MFC and first MTP joint was associated with all outcomes. Lower PPT (greater pressure pain sensitivity) was associated with greater knee pain severity. Associations of VPT and PPT with all outcomes were similar among females and males and Black and White individuals. CONCLUSIONS: Diminished vibration perception and greater pressure pain sensitivity were cross-sectionally associated with worse knee OA outcomes. Despite differences in VPT and PPT among females and males and Black and White adults, associations with knee OA outcomes did not differ by sex or race, suggesting neurophysiological differences do not relate to established disparities.
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Osteoartritis de la Rodilla , Umbral del Dolor , Presión , Vibración , Humanos , Osteoartritis de la Rodilla/fisiopatología , Masculino , Femenino , Anciano , Umbral del Dolor/fisiología , Estudios Transversales , Persona de Mediana Edad , Factores Sexuales , Índice de Severidad de la Enfermedad , Dimensión del Dolor , Artralgia/fisiopatología , Artralgia/etiologíaRESUMEN
INTRODUCTION: Pain sensitivity is the main finding of central sensitization (CS) and can occur in patients with chronic shoulder pain. However, there is limited evidence concerning the distribution of pain sensitivity in shoulders, forearms, and legs in patients with CS associated with chronic shoulder pain. The present study aimed to determine the distribution of pain sensitivity in patients with CS associated with chronic subacromial pain syndrome (SPS). METHOD: This cross-sectional study included 58 patients with chronic SPS and CS (patient group) and 58 healthy participants (control group). The presence of CS was determined using the Central Sensitization Inventory (CSI). To determine the distribution of pain sensitivity, pressure pain threshold (PPT) measurements were performed from the shoulders, forearms, and legs. RESULTS: There was no significant difference between the two groups in terms of sociodemographic data (p > 0.05). The patient group had a significantly higher CSI score (p < 0.001) and lower PPTs in all regions (p < 0.05) than the control group. Unlike the control group, the patient group had lower PPTs on the affected side for the shoulder [mean difference (MD) 95% confidence interval (CI): 1.2 (-1.7 to -0.6)], forearm [MD 95% CI: 1.1 (-1.7 to -0.6)], and leg [MD 95% CI: 0.9 (-1.4 to -0.3)] compared with the contralateral side (p < 0.001). CONCLUSION: Pain sensitivity is more pronounced in the affected shoulder and the forearm and leg located on this side than in those on the contralateral side in patients with CS associated with chronic SPS.
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Sensibilización del Sistema Nervioso Central , Dolor Crónico , Umbral del Dolor , Humanos , Estudios Transversales , Femenino , Masculino , Sensibilización del Sistema Nervioso Central/fisiología , Persona de Mediana Edad , Adulto , Umbral del Dolor/fisiología , Dolor Crónico/fisiopatología , Dolor de Hombro/fisiopatología , Síndrome de Abducción Dolorosa del Hombro/fisiopatología , Dimensión del Dolor , Antebrazo/fisiopatología , Pierna/fisiopatologíaRESUMEN
OBJECTIVE: This study aimed to investigate the effects of opioid-free anesthesia (OFA) in laparoscopic gastrectomy and identify the psychological factors that could influence the efficacy of OFA. METHOD: 120 patients undergoing laparoscopic gastrectomy were allocated to either the opioid-based anesthesia group (OA) (n = 60) or the OFA (n = 60) group. Remifentanil was administered to the OA group intraoperatively, whereas dexmedetomidine and lidocaine were administered to the OFA group. The interaction effect of the psychological factors on OFA was analyzed using the aligned rank transform for nonparametric factorial analyses. RESULTS: The opioid requirement for 24 h after surgery was lower in the OFA group than in the OA group (fentanyl equivalent dose 727 vs. 650 µg, p = 0.036). The effect of OFA was influenced by the pain catastrophizing scale (p = 0.041), temporal pain summation (p = 0.046), and pressure pain tolerance (p = 0.034). This indicates that patients with pain catastrophizing or high pain sensitivity significantly benefited from OFA, whereas patients without these characteristics did not. CONCLUSIONS: This study demonstrated that OFA with dexmedetomidine and lidocaine effectively reduced the postoperative 24-h opioid requirements following laparoscopic gastrectomy, which was modified by baseline pain catastrophizing and pain sensitivity. CLINICAL TRIAL REGISTRY: The study protocol was approved by the Institutional Review Board of Yonsei University Health System Gangnam Severance Hospital (#3-2021-0295) and registered at ClinicalTrials.gov (NCT05076903).
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Analgésicos Opioides , Dexmedetomidina , Gastrectomía , Lidocaína , Dolor Postoperatorio , Remifentanilo , Humanos , Masculino , Persona de Mediana Edad , Femenino , Analgésicos Opioides/administración & dosificación , Anciano , Dexmedetomidina/administración & dosificación , Dexmedetomidina/farmacología , Lidocaína/administración & dosificación , Lidocaína/farmacología , Dolor Postoperatorio/tratamiento farmacológico , Remifentanilo/administración & dosificación , Remifentanilo/farmacología , Laparoscopía , Catastrofización , Adulto , Umbral del Dolor/efectos de los fármacos , Anestésicos Locales/administración & dosificación , Anestésicos Locales/farmacologíaRESUMEN
BACKGROUND: Preoperative pain sensitivity (PPS) can be associated with postsurgical pain. However, estimates of this association are scarce. Confirming this correlation is essential to identifying patients at high risk for severe postoperative pain and for developing analgesic strategy. This systematic review and meta-analysis summarises PPS and assessed its correlation with postoperative pain. METHODS: PubMed, Scopus, Cochrane Library, and PsycINFO were searched up to October 1, 2023, for studies reporting the association between PPS and postsurgical pain. Two authors abstracted estimates of the effect of each method independently. A random-effects model was used to combine data. Subgroup analyses were performed to investigate the effect of pain types and surgical procedures on outcomes. RESULTS: A total of 70 prospective observational studies were included. A meta-analysis of 50 studies was performed. Postoperative pain was negatively associated with pressure pain threshold (PPT; r=-0.15, 95% confidence interval [CI] -0.23 to -0.07]) and electrical pain threshold (EPT; r=-0.28, 95% CI -0.42 to -0.14), but positively correlated with temporal summation of pain (TSP; r=0.21, 95% CI 0.12-0.30) and Pain Sensitivity Questionnaire (PSQ; r=0.25, 95% CI 0.13-0.37). Subgroup analysis showed that only TSP was associated with acute and chronic postoperative pain, whereas PPT, EPT, and PSQ were only associated with acute pain. A multilevel (three-level) meta-analysis showed that PSQ was not associated with postoperative pain. CONCLUSIONS: Lower PPT and EPT, and higher TSP are associated with acute postoperative pain while only TSP is associated with chronic postoperative pain. Patients with abnormal preoperative pain sensitivity should be identified by clinicians to adopt early interventions for effective analgesia. SYSTEMATIC REVIEW PROTOCOL: PROSPERO (CRD42023465727).
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Dolor Agudo , Dolor Crónico , Umbral del Dolor , Dolor Postoperatorio , Humanos , Dimensión del Dolor/métodos , Periodo PreoperatorioRESUMEN
OBJECTIVE: Migraine, a prevalent and debilitating disease, involves complex pathophysiology possibly including inflammation and heightened pain sensitivity. The current study utilized the complete Freund's adjuvant (CFA) model of inflammation, with onabotulinumtoxinA (BoNT/A) as a treatment of interest due to its use in clinical migraine management. Using an animal model, the study sought to investigate the role of BoNT/A in modulating CFA-induced inflammation, alterations in pain sensitivity, and the regulation of calcitonin gene-related peptide (CGRP) release. Further, we aimed to assess the changes in SNAP-25 through western blot analysis to gain insights into the mechanistic action of BoNT/A. METHODS: BoNT/A or control was administered subcutaneously at the periorbital region of rats 3 days before the induction of inflammation using CFA. Periorbital mechanical sensitivity was assessed post-inflammation, and alterations in CGRP release were evaluated. Changes in SNAP-25 levels were determined using western blot analysis. RESULTS: Upon CFA-induced inflammation, there was a marked increase in periorbital mechanical sensitivity, with the inflammation side showing increased sensitivity compared to other periorbital areas. BoNT/A did decrease the withdrawal thresholds in the electronic von Frey test. Despite not being able to observe differences in pain thresholds or CGRP release, BoNT/A reduced baseline release under CFA inflamed conditions. Analysis of SNAP-25 levels in the trigeminal ganglion revealed both intact and cleaved forms that were notably elevated in BoNT/A-treated animals. These findings, derived from western blot analysis, suggest an effect on neurotransmitter release. CONCLUSION: Our investigation highlights the role of BoNT/A in reducing baseline CGRP in the context of inflammation and its involvement in SNAP-25 cleavage. In contrast, BoNT/A did not appear to alter facial pain sensitivity induced by inflammation, suggesting that mechanisms other than baseline CGRP could be implicated in the elevated thresholds in the CFA model.
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Toxinas Botulínicas Tipo A , Péptido Relacionado con Gen de Calcitonina , Modelos Animales de Enfermedad , Inflamación , Trastornos Migrañosos , Ratas Sprague-Dawley , Proteína 25 Asociada a Sinaptosomas , Animales , Toxinas Botulínicas Tipo A/farmacología , Toxinas Botulínicas Tipo A/administración & dosificación , Trastornos Migrañosos/tratamiento farmacológico , Trastornos Migrañosos/metabolismo , Proteína 25 Asociada a Sinaptosomas/metabolismo , Péptido Relacionado con Gen de Calcitonina/metabolismo , Inflamación/tratamiento farmacológico , Ratas , Masculino , Adyuvante de Freund , Dolor/tratamiento farmacológico , Umbral del Dolor/efectos de los fármacos , Fármacos Neuromusculares/farmacología , Fármacos Neuromusculares/administración & dosificaciónRESUMEN
Background: Impaired glucose regulation is suggested to be related to chronic low back pain (CLBP), although it is not clear how they interact with each other. Thus, the primary aim of this study was to investigate differences in postprandial glycemic responses (PPGRs) (the first sign of impaired glucose metabolism) to high- (sucrose) and low-glycemic index (GI) (isomaltulose) beverages in normoglycemic women with CLBP and healthy controls (HCs) and explore whether any group that showed greater PPGRs to high-GI beverage intake would benefit when the high-GI beverage was replaced with a low-GI beverage. Secondly, this study aimed to explore the association between PPGR and pain in patients with CLBP. Methods: This study was registered at clinicaltrials.org (NCT04459104) before the start of the study. In this study, 53 CLBP patients and 53 HCs were recruited. After 11-12 h of fasting, each participant randomly received isomaltulose or sucrose. Blood glucose levels were measured during the fasting state and 15, 30, 45, 60, 90, and 120 min after the beverage intake, and each participant underwent experimental pain measures. Results: Compared to the HCs, the CLBP group showed significantly higher PPGRs to sucrose (p < 0.021). Additionally, the CLBP group showed a significantly higher decrease in PPGR (p = 0.045) when comparing PPGR to sucrose with PPGR to isomaltulose. Correlation analysis revealed a positive association between self-reported pain sensitivity and PPGR to sucrose, while there was no association found between any experimental pain measures and glycemic responses. Conclusions: Overall, these findings suggest that normoglycemic CLBP patients might have a higher risk of developing impaired glucose tolerance than the HCs and might benefit more when high-GI foods are replaced with low-GI ones.
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OBJECTIVES: First, we explored the association between Gender Role Expectations of Pain (GREP), and psychophysical measures of sensitization in people with knee osteoarthritis (OA). Second, we explored whether the association differed by level of GREP items (high vs low scores). DESIGN: We conducted secondary analyses of a cohort study. Those who were (i) age of ≥40, English or French speaking, ii) diagnosed with knee OA using American College of Rheumatology criteria and iii) consulting with an orthopedic surgeon were included. GREP items pertaining to pain sensitivity and pain endurance of the typical man or woman were rated by males and females respectively. Psychophysical tests consisted of pressure pain thresholds (PPTs), Temporal Summation (TS), and Conditioned Pain Modulation (CPM). Multiple linear regression models for males and females were run with GREP scores (independent variables) and psychophysical tests (dependent variables). Next models stratified on the median split of GREP scores were run. Models were adjusted for age, BMI, pain catastrophizing, anxio-depressive symptoms, and radiographic severity. RESULTS: 280 participants (57% females; age (SD): 63.9 (9.6) and BMI (SD): 31.3 (8.40)) were included. GREP pain sensitivity scores in males were associated with CPM values (ß: 95% CI: 0.09 (0.01 to 0.17)). Males with low GREP pain sensitivity or pain endurance had very small to small positive associations with PPT and CPM values. CONCLUSION: This first exploration of gendered pain sensitivity and pain endurance by males and females has small and clinically unimportant associations with measures of pain sensitization requiring further validation.
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Osteoartritis de la Rodilla , Dimensión del Dolor , Umbral del Dolor , Humanos , Masculino , Femenino , Osteoartritis de la Rodilla/fisiopatología , Osteoartritis de la Rodilla/psicología , Osteoartritis de la Rodilla/complicaciones , Persona de Mediana Edad , Estudios Transversales , Umbral del Dolor/fisiología , Anciano , Identidad de Género , Factores Sexuales , Catastrofización/psicologíaRESUMEN
BACKGROUND: The pain analgesia hypothesis suggests that reduced pain sensitivity (PS) is a specific risk factor for the engagement in non-suicidal self-injury (NSSI). Consistent with this, several studies found reduced PS in adults as well as adolescents with NSSI. Cross-sectional studies in adults with borderline personality disorder (BPD) suggest that PS may (partially) normalize after remission or reduction of BPD symptoms. The objective of the present study was to investigate the development of PS over 1 year in a sample of adolescents with NSSI and to investigate whether PS at baseline predicts longitudinal change in NSSI. METHODS: N = 66 adolescents who underwent specialized treatment for NSSI disorder participated in baseline and 1-year follow-up assessments, including heat pain stimulation for the measurement of pain threshold and tolerance. Associations between PS and NSSI as well as BPD and depressive symptoms were examined using negative binomial, logistic, and linear regression analyses. RESULTS: We found that a decrease in pain threshold over time was associated with reduced NSSI (incident rate ratio = 2.04, p = 0.047) and that higher pain tolerance at baseline predicted lower probability for NSSI (odds ratio = 0.42, p = 0.016) 1 year later. However, the latter effect did not survive Holm correction (p = 0.059). No associations between PS and BPD or depressive symptoms were observed. CONCLUSION: Our findings suggest that pain threshold might normalize with a decrease in NSSI frequency and could thus serve as a state marker for NSSI.
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BACKGROUND: Interventions that promote adaptive emotion regulation (ER) skills reduce pain in patients with chronic pain; however, whether the effects of yoga practice on chronic low back pain (CLBP) are due to improvements in ER remains to be examined. OBJECTIVE: This study will test whether the effects of yoga on CLBP (improved pain severity and interference) are mediated by improved ER, the extent to which effects are related to specific aspects of ER, and the role of pain sensitization as a mediator or moderator of effects. In this study, pain sensitization will be assessed by quantitative sensory testing and gene expression profiles to examine whether pain sensitization moderates yoga's effects on pain or whether yoga and ER abilities reduce pain sensitization, leading to decreased pain severity and interference. METHODS: For this 2-arm parallel group blinded randomized controlled trial, we will enroll 204 adults with CLBP who will be randomized to receive the yoga (n=102) or a control stretching and strengthening (n=102) intervention, which are delivered via web-based synchronous biweekly 75-minute sessions over 12 weeks. Participants are encouraged to practice postures or exercises for 25 minutes on other days using accessible prerecorded practice videos that are sent to participants digitally. Participants will be assessed at 5 time points: baseline, midintervention (6 weeks), postintervention (12 weeks), and 3- and 6-month follow-ups. Assessments of ER, pain severity and interference, pain sensitivity including somatosensory and gene expression profiles, and physical strength and flexibility will be conducted at each visit. The fidelity of the interventions is assessed using a manualized checklist to evaluate recorded group sessions to ensure consistent instructor delivery. RESULTS: The primary outcome will be the mean change in pain severity as measured by the Brief Pain Inventory-Short Form at 12 weeks. The primary mechanism of action is ER measured by change in the Difficulties in Emotion Regulation Scale total score. Secondary outcomes include pain sensitivity, physical strength and flexibility, pain interference, and quality of life. A mediation path analysis and series of moderated mediation path analyses will be conducted to test the study hypotheses. As of January 2024, we have enrolled 138 participants. We expect the study to be completed by May 2025. CONCLUSIONS: The study will provide important data for evaluating whether improvements in ER are responsible for reduced pain perception and pain sensitivity as well as increased quality of life in the context of chronic pain. The study findings have important implications for determining the mechanism of action for yoga and possibly other mind-body interventions as nonpharmacological therapies for pain management. The results of the study will inform the content, delivery, and measures for intervention trials involving yoga as a modality for relieving pain and improving function. TRIAL REGISTRATION: ClinicalTrials.gov NCT04678297; https://clinicaltrials.gov/study/NCT04678297. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/56016.
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The aim of the study was to investigate the effects of rat housing conditions-standard conditions, social isolation, environmental enrichment-and the subsequent reversal of these conditions on the vulnerability of the gastric mucosa to ulcerogenic stimuli, somatic pain sensitivity, and treadmill work capacity. Rats, aged 30 days, were placed in standard conditions (SC), social isolation (Is), and environmental enrichment (EE) for 4 weeks. Then half of each group underwent a reversal of housing conditions: SC rats were moved to Is, Is rats were placed in EE, EE rats were moved to Is, for 2 weeks. The other half served as a control with no change in their initial housing. Two weeks after the reversal, vulnerability of the gastric mucosa to ulcerogenic action of indomethacin (IM, 35 mg/kg, sc), somatic pain sensitivity (hot plate test), and work capacity (measured by the running distance on a treadmill) were assessed in control and reversed groups. Social isolation induced a proulcerogenic effect, increasing IM-induced gastric erosions, which was effectively reversed when rats were transferred to an environmental enrichment. Conversely, transferring rats from an environmental enrichment to social isolation exacerbated ulcerogenic action of IM. Somatic pain sensitivity and treadmill work capacity were also influenced by housing conditions, with environmental enrichment showing positive effects. The present findings show that social isolation of rats induces a proulcerogenic effect. Environmental enrichment reverses proulcerogenic action of social isolation on the gastric mucosa and increases resilience to pain stimuli and treadmill work capacity.
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Indometacina , Dolor Nociceptivo , Ratas , Animales , Ratas Sprague-Dawley , Indometacina/farmacología , Mucosa Gástrica , Aislamiento SocialRESUMEN
BACKGROUND: Latent inhibition occurs when exposure to a stimulus prior its direct associative conditioning impairs learning. Results from naturalistic studies suggest that latent inhibition disrupts the learning of dental fear from aversive associative conditioning and thereby reduces the development of dental phobia. Although theory suggests latent inhibition occurs because pre-exposure changes the expected relevance and attention directed to the pre-exposed stimulus, evidence supporting these mechanisms in humans is limited. The aim of this study is to determine if two variables, pre-exposure session spacing and multiple context pre-exposure, potentiate the hypothesized mechanisms of expected relevance and attention and, in turn, increase latent inhibition of dental fear. METHODS: In a virtual reality simulation, child and adult community members (ages 6 to 35) will take part in pre-exposure and conditioning trials, followed by short- and long-term tests of learning. A 100ms puff of 60 psi air to a maxillary anterior tooth will serve as the unconditioned stimulus. Pre-exposure session spacing (no spacing vs. sessions spaced) and multiple context pre-exposure (single context vs. multiple contexts) will be between-subject factors. Stimulus type (pre-exposed to-be conditioned stimulus, a non-pre-exposed conditioned stimulus, and an unpaired control stimulus) and trial will serve as within-subject factors. Baseline pain sensitivity will also be measured as a potential moderator. DISCUSSION: It is hypothesized that spaced pre-exposure and pre-exposure in multiple contexts will increase the engagement of the mechanisms of expected relevance and attention and increase the latent inhibition of dental fear. It is expected that the findings will add to theory on fear learning and provide information to aid the design of future interventions that leverage latent inhibition to reduce dental phobia.
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Condicionamiento Clásico , Ansiedad al Tratamiento Odontológico , Adulto , Niño , Humanos , Ansiedad al Tratamiento Odontológico/prevención & control , Condicionamiento Clásico/fisiología , Memoria , AtenciónRESUMEN
Purpose: In neonatal intensive care units, applying sucrose solution for analgesia is now a routine treatment for mild procedural pain. Studies of animal and human infants provide clear evidence of benefits in the short term, but few studies have investigated the long term benefits. Thus, we determined whether sucrose could ameliorate painful stimulation during infancy in Sprague-Dawley rats and also explored the long-term effects of repeated sucrose administration during infancy. Female and male rats were included to investigate sex-related differences. Methods: Rat pups were stimulated either with painful or tactile stimuli for the first 14 days of their lives. Pups were pretreated either with sucrose or not treated before stimulation. Behavioral tests were conducted during adolescence and adulthood. Hotplate, rotarod, open field, elevated plus maze, and radial arm water maze tests were employed to assess the behavioral consequences of early life manipulations and treatments. Results: Painful stimulation during infancy increased the sensitivity to pain later in life, and sucrose did not remedy this effect. Motility, coordination, anxiety, and cognition tests in adulthood obtained mixed results. Pain during infancy appeared to increase anxiety during adulthood. Learning and memory in adulthood were affected by pain during infancy, and sucrose had a negative effect even in the absence of pain. No sex-related differences were observed in any of the behavioral tests by employing this model of neonatal pain. Conclusion: Painful stimulation during infancy resulted in deficiencies in some behavioral tests later in life. Sucrose pretreatment did not mitigate these shortcomings and it actually resulted in negative outcomes.
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Aims and Objective: The purpose of this pilot study was to explore whether AIH produces changes in pain sensitivity or in reports of self-reported pain intensity for individuals with low back pain. Methods: In a quasi-experimental, cross-over design we compared participants (n = 9) exposed to normal room air and hypoxia using a commercially available gas blender. The treatment period consisted of 5 consecutive days of randomly assigned to AIH or room air. For the participants initially randomized to AIH there was cross-over to receive 5 more consecutive days of room air. Therefore, this design allowed for between group and within subject assessment of AIH effects. Pain sensitivity was assessed with quantitative sensory testing (QST) for posterior superior iliac spine pressure threshold, plantar thermal threshold, and peak pain ratings. Self-reported pain intensity for low back pain was assessed via the Brief Pain Inventory. Results: There were no between group differences for AIH and room air in pain sensitivity or self-reported pain intensity. In the within subject analyses larger effect sizes favoring AIH were detected for plantar measures of pain sensitivity but not for self-reported pain intensity. Conclusion: This study, while presenting null findings, describes an initial step in determining whether AIH can be used to increase pain relief. Based on this pilot study we offer guidance for future research including study design, AIH dosage, participant selection, and using AIH in combination with non-pharmacologic treatments.
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Stress is a series of physical and psychological responses to external and internal environmental stimuli. Growing studies have demonstrated the detrimental impacts of acute restraint stress (ARS) and chronic restraint stress (CRS) on animal behavior. However, the related pathogenesis and therapeutic mechanisms remain unclear. Hence, the present study aimed to examine whether unfolded protein response (UPR) and Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid 2 related factor 2 (Nrf2) pathway are associated with ARS- and CRS- induced abnormal behaviors of pain sensitivity and cognitive function. We here used four behavioral tests to evaluate pain sensitivity and cognitive function in ARS and CRS mice. CRS markedly decreased Paw Withdrawal Mechanical Threshold (PWMT) and Tail-flick Latency (TFL) scores, whereas ARS altered TFL but had no effect on PWMT scores. Additionally, CRS, but not ARS, significantly changed behaviors in nest building behavior and MWMT. Intriguingly, the expression of Keap1 and Nrf2 protein were decreased in the spinal cord and hippocampus in CRS mice, but not in ARS mice. Moreover, neither the ARS nor the CRS groups significantly differed from the control group in terms of endoplasmic reticulum stress (ERS). Taken together, this study demonstrated that CRS could induce abnormal pain sensitivity and cognitive function probably via Keap1/Nrf2 pathway in spinal cord and hippocampus. It is therefore likely that effective intervention of Keap1/Nrf2 pathway may contribute to preventing and treating hyperalgesia and cognitive dysfunction in CRS.
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Factor 2 Relacionado con NF-E2 , Estrés Psicológico , Ratones , Animales , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Psicológico/complicaciones , Estrés Psicológico/metabolismo , Estrés Oxidativo , Cognición , DolorRESUMEN
Background: The Pain Sensitivity Questionnaire (PSQ) is a reliable and valid self-reported tool for the assessment of pain sensitivity in clinical practice. The PSQ has been translated, validated, and cross-culturally adapted into multiple languages. However, a validated Arabic version of the PSQ is not available. Thus, this study aims to translate, validate, and cross-culturally adapt the English version of the PSQ into the Arabic language. Methods and materials: The English version of the PSQ was translated and culturally adapted into Arabic following international guidelines. The psychometric properties of the final version of the PSQ-Arabic (PSQ-A) were tested among 119 patients with different persistent musculoskeletal (MSK) pain. Findings: The Cronbach's α for the PSQ-A-total, PSQ-A-moderate, and PSQ-C-minor were 0.81, 0.79, and 0.76, respectively. The means for the PSQ-A-total, PSQ-A-moderate, and PSQ-C-minor scores were 5.07 (±1.28), 5.64 (±2.07), and 4.50 (±0.50). The test-retest reliability measured with the interclass correlation coefficient for 68 subjects was 0.80 for the PSQ-A-total, 0.74 for the PSQ-A-moderate, and 0.77 for the PSQ-A-minor. The PSQ-A-total and the PSQ-A-minor showed positive significant correlations with pain catastrophizing scale (PCS) (r = 0.15, 0.17); P ≤ 0.05), respectively. The PSQ-A-total, PSQ-A-moderate, and PSQ-A-minor showed positive significant correlations with the Brief Pain Inventory (BPI)-pain scores (r = 0.47, 0.43, 0.45; P ≤ 0.01), respectively and with the BPI-pain interference scores (r = 0.37, 0.33, 0.34; P ≤ 0.01), respectively. Conclusions: This study shows that the PSQ-A is a reliable and valid tool to assess individuals with pain sensitivity in Arabic populations. Further studies are recommended to examine the concurrent validity of the PSQ-A against experimental pain sensitivity measures.
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Introduction: Many clinical musculoskeletal pain conditions are characterized by chronic inflammation that sensitizes nociceptors. An unresolved issue is whether inflammation affects all nociceptors in a similar manner. Exercise-induced muscle damage (EIMD) has been proposed as a model for simulating clinical inflammatory pain in healthy samples. We sought to test the effect of EIMD on various painful stimuli (pressure and thermal), central pain processing (via the nociceptive flexion reflex) and endogenous pain modulation via conditioned pain modulation and exercise-induced hypoalgesia. Methods: Eighteen participants (9F, age: 24.6 ± 3.3) were recruited for repeated measures testing and each completed pain sensitivity testing prior to and 48 hours after an eccentric exercise protocol. The participants performed a minimum of 6 rounds of 10 eccentric knee extension exercises to induce muscle damage and localized inflammation in the right quadriceps. Force decrements, knee range-of-motion, and delayed onset muscle soreness (DOMS) were used to quantify EIMD. Results: There was a significant main effect of time for pressure pain (%diff; -58.9 ± 23.1; p = 0.02, ηp2 = 0.28) but no significant main effect was observed for limb (%diff; -15.5 ± 23.9; p = 0.53, ηp2 = 0.02). In contrast, there was a significant interaction between time and limb (p < 0.001, ηp2 = 0.47) whereby participants had lower pressure pain sensitivity in the right leg only after the damage protocol (%diff; -105.9 ± 29.2; p = 0.002). Discussion: Individuals with chronic inflammatory pain usually have an increased sensitivity to pressure, thermal, and electrical stimuli, however, our sample, following muscle damage to induce acute inflammation only had sensitivity to mechanical pain. Exercise induced inflammation may reflect a peripheral sensitivity localized to the damaged muscle rather than a global sensitivity like those with chronic pain display.