Opposite effects of isometric exercise on pain sensitivity of healthy individuals: the role of pain modulation.

Introduction: Exercise-induced hypoalgesia (EIHypo) among healthy individuals is well documented; however, the opposite effect of exercise, ie, exercise-induced hyperalgesia (EIHyper), has mainly been described in patients with chronic pain or after intense/painful exercise. Objectives: We investigated the extent to which EIHypo and/or EIHyper occur among healthy participants and whether these responses are associated with individuals' pain modulation capacity. Methods: Fifty-seven participants (mean age 29.20 ± 5.21 years) underwent testing of pressure pain threshold as an index of EIHypo/EIHyper: pain adaptation, offset analgesia (OA), and conditioned pain modulation as indices of pain modulation, prior to and immediately postsubmaximal isometric exercise (n = 40) or rest (n = 17, control group). Body awareness and exercise-evoked stress were also evaluated. Test-retest repeatability of the pain modulation indices was performed as well. Results: Twenty-four participants (60%) exhibited EIHypo, whereas 16 (40%) exhibited EIHyper. Pressure pain threshold did not change in the control group. Baseline (preexercise) OA efficacy predicted EIHypo/EIHyper. Furthermore, OA significantly decreased postexercise in the EIHyper subgroup and slightly increased in the EIHypo subgroup. Exercise-induced hypoalgesia was associated with magnitude of daily exercise while EIHyper was associated with increased exercise-evoked stress and body awareness. Conclusion: Submaximal isometric exercise can induce opposite effects on pain sensitivity among healthy participants-EIHypo or EIHyper. Descending pain inhibition pathways, and top-down influences over these pathways, seem to be involved in EIHypo/EIHyper effects. As such isometric exercise is often preferred in early stages of rehabilitation, preliminary screening individuals' vulnerability to this exercise is important; OA test may be used for this purpose.

Comparative Analysis of Pain and Duration in Panretinal Photocoagulation: Navilas Laser versus Conventional Laser in Proliferative Diabetic Retinopathy.

Objectives: To compare the pain perception and treatment duration in patients undergoing panretinal photocoagulation (PRP) for high-risk proliferative diabetic retinopathy (PDR) using Navilas laser versus conventional laser. Methods: A study was conducted involving 40 patients with bilateral high-risk PDR. Each patient underwent PRP with conventional laser in one eye and Navilas laser in the other. Laser parameters, including spot size and pulse duration were standardized. Pain perception was evaluated using Verbal Rating Scale (VRS) and Visual Analogue Scale (VAS). Results: The Navilas and conventional laser groups showed no significant differences in baseline visual acuity, lens status, intraocular pressure, cup-to-disc ratio, or cystoid macular edema. The duration of laser treatment was significantly shorter with Navilas laser group (517.3±48.78 seconds, p<0.001). Pain scores (VAS and VRS) were significantly lower in the Navilas laser group (p<0.001, p=0.002 respectively) than in conventional laser group. There was no correlation between VAS and VRS scores and laser time in both the Navilas and conventional laser groups (p>0.05). Conclusion: Utilizing the Navilas laser for PRP in PDR patients offers advantages over conventional lasers, including reduced pain and expedited procedures. These findings contribute valuable insights for optimizing clinical decisions, potentially enhancing patient compliance and minimizing the risk of visual deterioration in diabetic retinopathy treatment.

Pain Perception, Knowledge, Attitude, and Diet Diversity in Patients Undergoing Fixed Orthodontic Treatment: A Pilot Study.

Objective: This study aimed to determine the correlation between pain perception and knowledge, attitude, and diet diversity in patients undergoing fixed orthodontic treatment. Methods: A total of 103 patients (15-40 yrs.; 67 females, 36 males) undergoing orthodontic treatment with a 0.022-inch slot (MBT prescription) in both arches were recruited. Information on pain perception, knowledge, attitude, and diet diversity scores was collected through validated questionnaires using visual analogue scale and close-ended questions at one time point. The correlation between variables was analyzed using the Pearson's correlation coefficient. Results: Of the patients, 48.5% were aged 15 to 19 years old, with 65% females and 73.8% of Chinese ethnicity. Approximately 90% of the orthodontic patients perceived low levels of pain from orthodontic treatment, and 98% had a positive attitude toward orthodontic treatment. The patients had a good level of knowledge (Mean: 6±0.65). Approximately 49.5% of patients reported having moderate diet diversity. No significant correlation was found between pain perception and knowledge, or pain perception and diet diversity (r=0.062, p=0.534). However, a significant weak negative correlation (r=-0.289, p<0.05) between pain perception and attitude was observed. Conclusion: Patients undergoing fixed orthodontic treatment presented with overall low pain perception, a positive attitude, and good knowledge about their treatment with moderate diet diversity. Informing the patient in advance about different orthodontic procedures encourages a positive attitude and facilitates patient cooperation. An interprofessional approach involving nutritionists can provide a holistic patient approach during orthodontic treatment.

Associations of Treatment Outcome Expectations and Pain Sensitivity after Cervical Spine Manipulation in Patients with Chronic Non-Specific Neck Pain: A Cohort Study.

(1) Background: This cohort study aimed to evaluate the effect of patients' treatment expectations on pain perception changes following manual therapy cervical manipulations in individuals with chronic mechanical neck pain. (2) Methods: Demographic data were collected by 56 subjects who were asked to fill out the Neck Disability Index (NDI) and the Expectations for Treatment Scale (ETS). All patients received one single cervical manipulation, and pressure pain thresholds (PPTs) were measured before and immediately after the manipulation with a digital algometer. (3) Results: A total of 56 patients participated. Most subjects (62.5%) had high treatment expectations according to the ETS scale. Statistically significant increases in PPTs were noted both locally and in remote areas (p < 0.05), with 37.5-48.2% of participants showing clinically significant changes in pain perception. However, no statistically significant correlation was found between high treatment expectations and increased PPTs (p > 0.05). (4) Conclusions: Although a significant reduction in pain perception was observed, it did not correlate with patients' treatment expectations. Future research for further investigation of this hypothesis by comparing real versus sham treatment and exploring additional mechanisms affecting changes in PPTs after cervical manipulations in this population will contribute to a better understanding of the research question.

A myriad of methods to determine temporal summation of pain in people with musculoskeletal pain and healthy participants: a scoping review.

Temporal summation of pain (TSP) is a human proxy for wind-up of dorsal horn neurons as assessed in animals. The common paradigm for eliciting TSP is evoked by repetitive nociceptive stimuli of equal intensity. Various stimulation and assessment protocols have been used. This scoping review aims to provide insight into key elements of TSP stimulation and assessment: modality, instruments, test location, familiarization, train characteristics, and calculations. PubMed, Embase, and Ebsco/CINAHL were searched for studies that measured TSP in adults with musculoskeletal conditions and healthy people. Four hundred six studies were included. Mechanical stimuli were the most commonly used modality (250 studies), followed by thermal stimuli (125 studies). Forty-six different instruments were used. Disregarding studies on widespread musculoskeletal pain and healthy participants, 40 studies evaluated TSP at painful sites, 77 in remote areas, and 66 in both locations. Of the 13 tested locations in patients, the hand (74 studies), lower leg (64 studies), and forearm (59 studies) were most commonly tested. A single practice round was the most common familiarization method (46 studies). Repeated stimuli were applied using 31 different frequencies (0.03-200 Hz) and sustained stimulations ranging from 5 to 1080 seconds were used. Twenty-two different train lengths, 63 different calculations (37 absolute, 19 relative, and 7 alternatives using data directly), and 14 different outcome measures (eg, self-reported pain rating scales and reflex thresholds) were used. Temporal summation of pain protocols vary excessively, hindering the comparison and pooling of results. None of the studies provided substantiation for their protocol choice.

One Size Does Not Fit All: Women Experience More Pain Than Men After Total Knee Arthroplasty.

BACKGROUND: Multimodal pain regimens are universally applied to all patients, despite known differences in pain and responses to medication between patients of different sexes, ethnicities, and races. The purpose of this study was to understand the influence of patient sex on postoperative total knee arthroplasty pain perception as well as the efficacy of perioperative pregabalin for pain control. METHODS: Visual analog Scales (VASs) and Knee Injury and Osteoarthritis Outcome Junior (KOOS Jr.) scores were prospectively collected for 150 patients (64 men and 86 women). Mean pain scores, delta pain scores, time to achieve minimal clinically important differences, influence of pregabalin, and opioid consumption were recorded at baseline, day of surgery, 24 hours, 48 hours, and 72 hours postoperatively, as well as postoperatively weeks 1, 2, 6, 12, and 26, and compared between women and men cohorts. This study was registered on ClinicalTrials.gov (NCT04471233). RESULTS: The VAS pain scores for women were higher than for men at all study time points (P < 0.05). The change in VAS walking and mean KOOS Jr. scores from baseline to final follow-up at 26 weeks were not significantly different between cohorts. Both cohorts achieved VAS minimal clinically important difference by 2 weeks postoperatively. No significant differences in opioid consumption between men and women were noted during the study time periods. Women were also noted to have significantly higher raw KOOS Jr. scores than men at all-time points, except for at 26 weeks postoperatively. Interim analysis revealed no significant influence of pregabalin on VAS scores, so this arm of the study was discontinued. CONCLUSIONS: Patient sex plays a role in perceived postoperative total knee arthroplasty pain, as women reported higher pain scores than men. We recommend not overly relying on standardized protocols, but rather instituting patient-specific pain management strategies.

Effects of Mindfulness Meditation on Patient Experience During Urodynamics: A Prospective Study.

INTRODUCTION AND HYPOTHESIS: Urodynamics (UDS) assesses voiding dysfunction using intravesical, vaginal, or rectal catheters, which can be distressing. This study was aimed at utilizing mindfulness to reduce anxiety and pain in patients undergoing UDS. METHODS: A single-institution randomized controlled trial was conducted on 60 patients who underwent UDS. Patients were assigned to a mindfulness group (n = 30) or a control group (n = 30). Before UDS testing, all patients completed validated questionnaires assessing lower urinary tract symptoms (Urogenital Distress Inventory 6, UDI-6), anxiety (State-Trait Anxiety Inventory 6, STAI-6), and pain (Visual Analog Scale, VAS). The mindfulness group listened to a mindfulness audio prompt before UDS. All patients received standardized UDS education before UDS testing in a calm environment. After UDS testing, all patients completed validated UDS-perception questionnaires, STAI-6, Likert scale, and VAS surveys. Statistical analysis was performed using paired t tests, independent t tests, Wilcoxon, and Chi-squared tests. RESULTS: Both groups had similar demographics, history of prior UDS, anxiety, and baseline UDI-6 and STAI-6. Post-UDS, anxiety scores decreased in both groups, with the mindfulness group reporting significant improvement in "calmness" (mean 1.7, SD = 0.84) compared with the control group (mean 2.3, SD = 1.0, p < 0.05). The mindfulness group reported increased relaxation whereas the control group reported decreased relaxation post-UDS. Patients in both groups without a history of UDS had a significant improvement in total anxiety compared with those with a history of UDS. CONCLUSION: Mindfulness meditation may improve calmness and relaxation for patients undergoing UDS.

Effects of Chronic Prenatal Alcohol Exposure on Nociceptive Responses to Mechanical and Thermal Stimuli in Rats.

The present study sought to investigate the effects of chronic prenatal alcohol exposure (PAE) on nociceptive responses to mechanical and thermal stimuli in rats. The Von Frey and Hot Plate tests were employed to assess the nociceptive responses of 10 control rats and 7 experimental rats whose mothers had been administered ethanol from day 5 to day 20 of gestation. In healthy animals, a decrease in pain sensitivity was observed between days 28 and 70, which was not observed in the experimental group. The findings also indicated that rats with PAE exhibited diminished sensitivity to nociceptive stimuli during the early postnatal period, as evidenced by a higher threshold response to mechanical stimuli at day 28 than in the control group. However, those observations did not apply to thermal stimuli. It appears that this may be a result of distinctiveness in neural pain pathways for particular stimuli at the receptor or ion channel level, while a disruption in the equilibrium between the sympathetic and parasympathetic nervous systems may be a contributing factor. The results of this study highlight a critical aspect of the harmful systemic effects of alcohol, while also underscoring the need for further research to elucidate the underlying mechanisms, including the role of the hypothalamic-pituitary-adrenal axis and the serotonergic system in modulating pain responses in individuals prenatally exposed to alcohol.

The Usefulness of Virtual Reality in Symptom Management during Chemotherapy in Lung Cancer Patients: A Quasi-Experimental Study.

Background: Virtual reality (VR) emerges as a promising non-pharmacological intervention for managing symptoms and providing distraction during chemotherapy. This study aims to assess VR's effectiveness on cancer-related symptoms, vital signs, and the patients' perception of chemotherapy in lung cancer patients. Methods: A quasi-experimental study was conducted on 100 patients. Participants were allocated into an intervention group (n = 55), which experienced immersive VR, and a comparison group (n = 45), which received usual care. Data were collected through questionnaires and checklists, including feedback on the VR experience, pain, vital signs, and common cancer symptoms, assessed through the Edmonton Symptom Assessment Scale. Results: VR had a significant impact on reducing the perception of chemotherapy length. Patients reported high levels of satisfaction and tolerability. No adverse events were observed. VR did not have significant influence on pain intensity or vital signs. The only exceptions were oxygen saturation, where a significant difference (p = 0.02) was reported, and the perception of chemotherapy duration. Conclusions: As a non-pharmacological intervention, VR proves to be beneficial in minimizing the perceived length of chemotherapy sessions for lung cancer patients, enhancing their overall treatment experience. The intervention was found to be a safe, feasible, and well-accepted distraction technique. Future research should explore VR's potential effects on a wider range of symptoms and evaluate its impact on long-term outcomes.

Efficacy of computer-controlled local anesthesia delivery system on pain in dental anesthesia: a systematic review of randomized clinical trials.

Computer-controlled local anesthesia delivery (CCLAD) is an innovative electronic injection device that represents a cutting-edge approach to dental anesthesia. This system is promising for painless anesthesia using controlled anesthetic injections. This review aimed to compare the discomfort experienced by patients during local anesthesia using a traditional syringe and the CCLAD system and evaluate the potential of the CCLAD system as a painless dental anesthesia solution. The inclusion criteria for this study were based on the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The study population, including children and adults, underwent dental anesthesia using the CCLAD system, ensuring a comprehensive and representative sample that instills confidence in the validity of the results. Fourteen clinical trials were included in the analysis after they fulfilled the eligibility criteria. We found that using computer-assisted anesthetic equipment not only led to a significantly lower pain perception score, but also had a profound positive impact on patient behavior. Patients using the CCLAD device exhibited more cooperative and helpful conduct, indicating the system's effectiveness in improving patient comfort and experience and reassuring the audience about its positive impact. In conclusion, using a computer-assisted anesthetic device such as the CCLAD system significantly reduced pain perception scores and improved patient behavior, making them more cooperative and helpful. These findings offer hope for pediatric dentistry and apprehensive adult patients, suggesting a more comfortable and less daunting dental experience with the CCLAD system.

Structural MRI findings in the brain related to pain distribution in chronic overlapping pain conditions: An explorative case-control study in females with fibromyalgia, temporomandibular disorder-related chronic pain and pain-free controls.

BACKGROUND: Few neuroimaging studies have investigated structural brain differences associated with variations in pain distribution. OBJECTIVE: To explore structural differences of the brain in fibromyalgia (FM), temporomandibular disorder pain (TMD) and healthy pain-free controls (CON) using structural and diffusion MRI. METHODS: A case-control exploratory study with three study groups with different pain distribution were recruited: FM (n = 16; mean age [standard deviation]: 44 [14] years), TMD (n = 17, 39 [14] years) and CON (n = 10, 37 [14] years). Participants were recruited at the University Dental Clinic in Malmö, Sweden. T1-weighted and diffusion MRIs were acquired, clinical and psychosocial measures were obtained. Main outcome measures were subcortical volume, cortical thickness, white matter microstructure and whole brain grey matter intensity. RESULTS: Patients with FM had smaller volume in the right thalamus than patients with TMD (p = .020) and CON (p = .030). The right thalamus volume was negatively correlated to pain intensity (r = -0.37, p = .022) and pain-related disability (r = -0.45, p = .004). The FM group had lower cortical thickness in the right anterior prefrontal cortex than CON (p = .005). Cortical thickness in this area was negatively correlated to pain intensity (r [37] = - 0.48, p = .002). CONCLUSIONS: This study suggests that thalamus grey matter alterations are associated with FM and TMD, and that anterior prefrontal cortex grey matter alterations are associated with FM but not TMD. Studies on chronic overlapping pain conditions are needed in relation to possible nociplastic pain mechanisms in the brain and central nervous system.

An approach to the detection of pain from autonomic and cortical correlates.

OBJECTIVE: To assess the value of combining brain and autonomic measures to discriminate the subjective perception of pain from other sensory-cognitive activations. METHODS: 20 healthy individuals received 2 types of tonic painful stimulation delivered to the hand: electrical stimuli and immersion in 10 Celsius degree (°C) water, which were contrasted with non-painful immersion in 15 °C water, and stressful cognitive testing. High-density electroencephalography (EEG) and autonomic measures (pupillary, electrodermal and cardiovascular) were continuously recorded, and the accuracy of pain detection based on combinations of electrophysiological features was assessed using machine learning procedures. RESULTS: Painful stimuli induced a significant decrease in contralateral EEG alpha power. Cardiac, electrodermal and pupillary reactivities occurred in both painful and stressful conditions. Classification models, trained on leave-one-out cross-validation folds, showed low accuracy (61-73%) of cortical and autonomic features taken independently, while their combination significantly improved accuracy to 93% in individual reports. CONCLUSIONS: Changes in cortical oscillations reflecting somatosensory salience and autonomic changes reflecting arousal can be triggered by many activating signals other than pain; conversely, the simultaneous occurrence of somatosensory activation plus strong autonomic arousal has great probability of reflecting pain uniquely. SIGNIFICANCE: Combining changes in cortical and autonomic reactivities appears critical to derive accurate indexes of acute pain perception.

Association Between Pain During Pregnancy and Postpartum Depressive Symptoms in Adolescent and Adult Women.

ISSUE: Postpartum depressive symptoms may be more prevalent and/or severe in vulnerable populations. BACKGROUND: Postpartum depression represents a serious mental health problem associated with maternal suffering. Despite the relevance and clinical implications of investigating pain during pregnancy and the association with postpartum depression, there is limited research on this topic. AIM: We evaluated the association between pain during pregnancy and postpartum depression symptoms in adolescent and adult women. METHODS: This study included 86 pregnant women (42 adolescents aged 13 to 18 years and 44 adults aged 23 to 28 years) from Trairi region, Northeastern Brazil. The evaluation of pain intensity and postpartum depression symptoms was conducted using the validated instruments of the Pelvic Pain Assessment Form and Edinburgh Postnatal Depression Scale (EPDS), respectively. Mann-Whitney and Kruskal-Wallis tests compared depressive symptoms in relation to pain status. FINDINGS: Overall, pregnant women reporting moderate to intense pain presented more depressive symptoms, with emphasis to "deep pain with intercourse" (p = .09), "burning vaginal pain after sex" (p = .01), "pelvic pain lasting hours or days after intercourse" (p = .06), and "pain with urination" (p = .09). When stratified by age group, significant associations were found only for the adolescents. DISCUSSION: Our results suggest that women reporting pain in different daily situations have higher EPDS scores. CONCLUSION: Pain during pregnancy is associated with postpartum depression symptoms, mainly among adolescents. Adequate screening and pain management during pregnancy may improve women's quality of life.

Effects of hippocampal damage on pain perception in a rat model of Alzheimer's disease induced by amyloid-ß and ibotenic acid injection into the hippocampus.

Patients with Alzheimer's disease (AD) present with a variety of symptoms, including core symptoms as well as behavioral and psychological symptoms. Somatosensory neural systems are generally believed to be relatively unaffected by AD until late in the course of the disease; however, somatosensory perception in patients with AD is not yet well understood. One factor that may complicate the assessment of somatosensory perception in humans centers on individual variations in pathological and psychological backgrounds. It is therefore necessary to evaluate somatosensory perception using animal models with uniform status. In the current study, we focused on the hippocampus, the primary site of AD. We first constructed a rat model of AD model using bilateral hippocampal injections of amyloid-ß peptide 1-40 and ibotenic acid; sham rats received saline injections. The Morris water maze test was used to evaluate memory impairment, and the formalin test (1 % or 4 % formalin) and upper lip von Frey test were performed to compare pain perception between AD model and sham rats. Finally, histological and immunohistochemical methods were used to evaluate tissue damage and neuronal activity, respectively, in the hippocampus. AD model rats showed bilateral hippocampal damage and had memory impairment in the Morris water maze test. Furthermore, AD model rats exhibited significantly less pain-related behavior in phase 2 (the last 50 min of the 60-minute observation) of the 4 % formalin test compared with the sham rats. However, no significant changes were observed in the von Frey test. Immunohistochemical observations of the trigeminal spinal subnucleus caudalis after 4 % formalin injection revealed significantly fewer c-Fos-immunoreactive cells in AD model rats than in sham rats, reflecting reduced neuronal activity. These results indicate that AD model rats with hippocampal damage have reduced responsiveness to persistent inflammatory chemical stimuli to the orofacial region.

Effect of verbal and written information on the perception of pain and analgesic consumption, in adolescent orthodontic patients: A randomised controlled trial.

OBJECTIVE: To investigate the impact of written instructions, about post-bonding pain, on patients' pain perception and analgesic consumption and to evaluate the correlation of pain with personality types. DESIGN: Two-arm parallel randomised controlled trial. SETTING: University Hospital Centre Zagreb, Zagreb, Croatia. METHODS: Participants included adolescents in the permanent dentition with mild or moderate crowding. RANDOMISATION: The participants were randomly allocated, using computer-generated random list, into two groups. INTERVENTIONS: After bonding and archwire insertion, all participants received oral instructions on potential pain occurrence and pain control. Participants in the study group also received written information on post-bonding pain. OUTCOMES: Pain intensity was evaluated using the Numerical Rating Scale immediately after (T0), 2 days (T1) and 7 days (T2) after the placement of the fixed orthodontic appliance. Analgesic consumption was assessed as yes or no, and personality traits were assessed using the Big Five Inventory. Operators who scored pain intensity and recorded analgesic consumption and personality traits were blinded to the group allocation. Statistical analyses included the t-test, Mann-Whitney U-test, Spearman correlations and stepwise regression analysis. RESULTS: The highest rate of pain was recorded at T1 (P < 0.001). No statistically significant difference in pain perception between groups was observed. There was no statistically significant difference in analgesic consumption between the two groups (P = 0.81). The correlations between personality traits and pain perception were not significant. CONCLUSION: The additional written information had little impact on pain perception, and it had no relationship to personality types. The perception of pain and analgesic consumption were not affected by the provision of additional written information (P = 0.81). Participants' personality types did not affect the impact of the information given.

The effect of chewing gum on the rate of en-masse space closure: A randomised controlled trial.

AIM: To evaluate the effect of chewing gum on the rate of space closure, oral hygiene, pain during space closure and appliance breakage in patients undergoing fixed appliance therapy. DESIGN: A prospective, single-centre, two-arm, parallel, double-blinded randomised controlled trial. SETTING: Orthodontic unit of a privately funded hospital, Chennai, India. PARTICIPANTS: In total, 28 participants were randomly allocated into a chewing gum group (CGG) (n = 14) or a control group (CG) (n = 14). METHODS: Baseline data were collected at the start of retraction (T0), at 4 weeks (T1), 8 weeks (T2) and 12 weeks (T3) after the start of retraction. Rate of space closure, pain, oral hygiene and appliance breakage were assessed at T1, T2 and T3. Data were analysed using an independent t-test with P < 0.05 considered to be statistically significant. RESULTS: The mean rate of space closure in the CGG was 0.9 ± 0.2 mm/month and 0.8 ± 0.2 mm/month in the CG (P = 0.07, 95% confidence intervals [CI] were 0.80-1.01 for the CGC and 0.70-0.91 for the CG). In both the groups, oral hygiene became worse between T0 and T3. At T0 and T1, participants in the CGG reported less pain at 24 h and 7 days when compared to the CG (P < 0.05). At T2 and T3, participants in the CGG reported less pain at 0 h, 24 h and 7 days when compared to the CG (P < 0.05). Appliance breakage in both groups was minimal, with an odds ratio of 0.7 (95% CI 0.1-3.8) and was similar (P = 0.66). CONCLUSION: There was minimal increase that was clinically not significant in the rate of space closure with chewing gum. Chewing gum ensured better oral hygiene, helped alleviate pain and had no effect on appliance breakage during space closure.

Effect of exercise and manual therapy or kinesiotaping on sEMG and pain perception in chronic low back pain: a randomized trial.

The importance of incorporating lumbo-pelvic stability core and controlling motor exercises in patients with chronic low back pain (CLBP) reinforces the use of strategies to improve biopsychosocial beliefs by reducing biomedical postulations. However, clinical practice guidelines recommend multimodal approaches incorporating exercise and manual therapy (MT), and instead reject the application of kinesiotape (KT) in isolation. Therefore, the objectives of this study were to analyze the effects of 12 weeks of exercises combined with MT or KT on perceived low back pain using the visual analog scale (VAS) and muscle electric activity measured with electromyography (EMG) of the rectus abdominis and multifidus in CLBP (mild disability) and to explore the relationship between the rectus abdominis and multifidus ratios and pain perception after intervention. A blinded, 12-week randomized controlled trial (RCT) was carried out, involving three parallel groups of patients with CLBP. The study was registered at Clinicaltrial.gov and assigned the identification number NCT05544890 (19/09/22). The trial underwent an intention-to-treat analysis. The primary outcome revealed a multimodal treatment program supplemented by additional therapies such as MT and KT, resulting in significant reductions in perceived low back pain. The subjective assessment of individuals with CLBP indicated no discernible distinction between exclusive core stability exercises and control-motor training when combined with MT or KT. Notably, our findings demonstrated positive alterations in both the mean and peak EMG values of the right rectus abdominis in the exercise group, suggesting a beneficial impact on muscle activation. This study focused on assessing the activation levels of the trunk musculature, specifically the rectus abdominis (RA) and multifidus (MF), in individuals with CLBP exhibiting mild disability according to the Oswestry Disability Index. Importantly, improvements in the VAS values were observed independently of changes in muscle electrical activity.

Tannic acid inhibits pain mediators, inflammation and oxidative stress in mice exposed to glyphosate-based herbicide.

Chronic exposure to glyphosate-based herbicide (Gly) has been associated with neurological disorders. Tannic acid (TA) is an antioxidant with attenuating action against neuroinflammation-associated conditions. This study evaluated the effect of Gly on pain perception alongside antinociceptive and anti-inflammatory actions of TA in Gly-exposed mice. Male Swiss mice were randomly divided into six groups (n=8): control (distilled water 0.2 ml/kg), Gly (Gly 500 mg/kg), Pre-TA + Gly (TA 50 mg/kg pre-treatment, afterwards Gly-administered), TA + Gly (TA 50 mg/kg and Gly co-administered), Pre-AA + Gly (ascorbic acid (AA) 10 mg/kg pre-treatment, afterwards Gly-administered), and AA + Gly (AA 10 mg/kg and Gly co-administered). Mechanical, thermal, and chemical pain were evaluated six weeks post vehicle/drugs administrations orally, followed by brain biochemical measurements. TA treatment alleviated Gly-induced hyperalgesia in similar version to the values of control and AA groups by increasing significantly (p < 0.05) nociceptive thresholds. Moreover, TA-treatment significantly decreased malondialdehyde (MDA) and pro-inflammatory cytokines (TNF-α, IL-1ß, and IL-6) levels, significantly increased anti-inflammatory cytokines (IL-10, IL-4, and TGF-1ß) levels, and antioxidant enzymes, catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD) activities compared to Gly-treated mice (p < 0.05). Conclusively, TA treatment exerted antinociceptive and anti-inflammatory actions, possibly through its antioxidant and anti-inflammatory actions in Gly-exposed mice. Notably, TA pre-treatment showed a better response than TA and Gly co-administration. We propose the potential neuroprotective and ameliorative functions of TA in Gly-induced hyperalgesia. This merits further clinical research into protective roles of TA against pesticide-related conditions.

Emotions in search of words: Does alexithymia predict treatment outcome in chronic musculoskeletal pain?

Chronic pain, with its complex and multidimensional nature, poses significant challenges in identifying effective long-term treatments. There is growing scientific interest in how psychopathological and personality dimensions may influence the maintenance and development of chronic pain. This longitudinal study aimed to investigate whether alexithymia can predict the improvement of pain severity following a treatment-as-usual programme for chronic musculoskeletal pain over and above psychological cofactors (emotional distress, catastrophizing, and self-efficacy). A consecutive sample of 129 patients with diagnosed chronic musculoskeletal pain referred to two tertiary care centres was recruited and treated for 16 weeks. Clinical pain, psychological distress, self-efficacy, catastrophizing, and alexithymia were assessed with validated self-report measures at the first medical visit (T0) and at 16-week follow-up (T1). Compared with non-responder patients (n = 72, 55.8%), those who responded (i.e., reduction of >30% in pain severity; n = 57, 44.2%) reported an overall improvement in psychological variables except alexithymia. Alexithymia showed relative stability between baseline and follow-up within the entire sample and remained a significant predictor of treatment outcome even when other predictive cofactors (i.e., pain interference, depressive symptoms, and catastrophizing) were considered simultaneously. Our results suggest that identifying patients with a co-occurrence between alexithymia, depressive symptoms, catastrophizing, and the stressful experience of chronic pain can be clinically relevant in pain prevention and intervention programs.