Non-obese lipedema patients show a distinctly altered quantitative sensory testing profile with high diagnostic potential

Introduction and Objectives

Lipedema is a widespread severe chronic disease affecting mostly women. Characterized by painful bilateral fat accumulation in extremities sparing hands and feet, objective measurement-based diagnosis is currently missing. We tested for characteristic psychometric and/or sensory alterations including pain and for their potential for medical routine diagnosis.

Methods

Pain psychometry was assessed using the German Pain Questionnaire. Sensory sensitivity toward painful and nonpainful stimuli was characterized in non-obese lipedema patients and matched controls using the validated quantitative sensory testing (QST) protocol of the German Research Network on Neuropathic Pain.

Results

Lipedema patients showed no overt psychometric abnormalities. Pain was reported as somatic rather than psychosomatic aversive. All QST measurements were normal, but the z-score of pressure pain thresholds (PPT) was twofold reduced and the z-score of vibration detection thresholds (VDT) was two and a half times increased. Both thresholds were selectively altered at the affected thigh but not the unaffected hand. Receiver operating characteristic analysis of the combination of PPT and VDT of thigh vs hand into a PVTH score (PPT, VDT, thigh, hand-score) shows high sensitivity and specificity, categorizing correctly 95.8% of the participants as lipedema patients or healthy controls. Bayesian inference analysis corroborated the diagnostic potential of such a combined PVTH score.

Conclusion

We propose to assess PPT and VDT at the painful thigh and the pain-free hand. Combination in a PVTH score may allow a convenient lipedema diagnosis early during disease development.

Ferulic acid via attenuation of oxidative stress and neuro-immune response utilizes antinociceptive effect in mouse model of formalin test

Introduction

Plenty evidences suggests that neuroinflammation and oxidative stress augmented the neural sensitivity specifying that neuro-immune response is involved in the pathophysiology of pain. Ferulic acid (FA), a natural antioxidant found in various fruits, has various pharmacological properties. The purpose of the current study was to assess the antinociceptive effect of FA in a mouse model of formalin test with focus on its anti-neuroinflammatory and antioxidative stress effects.

Methods

The injection of FA (40 mg/kg), piroxicam (2 mg/kg), and saline (0.9% NaCl) (1 ml/kg) was done intraperitoneally and after one hour, formalin injected into the plantar surface of the hind paw of mice. Then pain behavior was documented during 60 min. Then mice were euthanized and prefrontal cortex (PFC) samples were taken. Malondialdehyde (MDA) level, antioxidant capacity and expression of inflammatory genes, counting tumor necrosis factor (TNF-) and interleukine 1 (IL-1) evaluated in the PFC.

Results

exhibited that FA declined the pain behavior following injection of formalin. Besides, FA significantly diminished the MDA level and increased the antioxidant capacity in the PFC. We revealed that FA diminished the expression of TNF-α and IL-1β genes in the PFC.

Conclusion

We conclude that FA exerted antinociceptive effects in the formalin test in mice, at least partially, by reducing oxidative stress and neuroimmune response in the PFC.

Shared comorbidity of depression, migraine, insomnia, and fibromyalgia in a population-based sample

BACKGROUND

Depression, migraine, insomnia, and fibromyalgia are reportedly comorbidities. Nevertheless, no study has evaluated the comorbidity of all four of these disorders. This study aimed to investigate the comorbidity of these four disorders.

METHODS

Cross-sectional analyses were performed using data of the Circannual Change in Headache and Sleep study, an online nationwide population-based survey. Validated questionnaires were used to diagnose the disorders and measure quality of life. The change of clinical characteristics by addition of any comorbidity was analyzed using the Jonckheere-Terpstra trend test.

RESULTS

The prevalence rates of depression, migraine, insomnia, and fibromyalgia were 7.2 %, 5.6 %, 13.3 %, and 5.8 %, respectively. Among the 3030 included participants, 494 (16.3 %), 164 (5.4 %), 40 (1.3 %), and 6 (0.2 %) had one, two, three, and four of these conditions, respectively. The number of headache days per 30 days (Jonckheere-Terpstra trend test, p = 0.011) and migraine-related disability (migraine disability assessment score, p = 0.021) increased with an increase in the number of comorbidities but not with the intensity of headache (visual analog scale, p = 0.225) among participants with migraine. The severity of insomnia (Insomnia Severity Index, p < 0.001) and fibromyalgia (fibromyalgia severity score, p = 0.002) increased with additional comorbidities; however, depression (Patient Health Questionnaire-9, p = 0.384) did not show such an increase.

LIMITATIONS

The diagnoses of conditions were based on self-reported questionnaires.

CONCLUSIONS

The findings confirmed significant comorbidity between depression, migraine, insomnia, and fibromyalgia. Health professionals should be aware of the probable comorbidity of depression, migraine, insomnia, and fibromyalgia when caring for individuals with any of these four disorders.

Schisandrin B from Schisandra chinensis alleviated pain via glycine receptors, Nav1.7 channels and Cav2.2 channels

ETHNOPHARMACOLOGICAL RELEVANCE

Schisandra chinensis, the dried and ripe fruit of the magnolia family plant Schisandra chinensis (Turcz.) Baill, was commonly used in traditional analgesic prescription. Studies have shown that the extract of Schisandra chinensis (SC) displayed analgesic activity. However, the analgesic active component and the exact mechanisms have yet to be revealed.

AIM OF THE STUDY

The present study was to investigate the anti-nociceptive constituent of Schisandra chinensis, assess its analgesic effect, and explore the potential molecular mechanisms.

MATERIALS AND METHODS

The effects of a series of well-recognized compounds from SC on glycine receptors were investigated. The analgesic effect of the identified compound was evaluated in three pain models. Mechanistic studies were performed using patch clamp technique on various targets expressed in recombinant cells. These targets included glycine receptors, Nav1.7 sodium channels, Cav2.2 calcium channels et al. Meanwhile, primary cultured spinal dorsal horn (SDH) neurons and dorsal root ganglion (DRG) neurons were also utilized.

RESULTS

Schisandrin B (SchB) was a positive allosteric modulator of glycine receptors in spinal dorsal horn neurons. The EC50 of SchB on glycine receptors in spinal dorsal horn neurons was 2.94 ± 0.28 μM. In three pain models, the analgesic effect of SchB was comparable to that of indomethacin at the same dose. Besides, SchB rescued PGE2-induced suppression of α3 GlyR activity and alleviated persistent pain. Notably, SchB could also potently decrease the frequency of action potentials and inhibit sodium and calcium channels in DRG neurons. Consistent with the data from DRG neurons, SchB was also found to significantly block Nav1.7 sodium channels and Cav2.2 channels in recombinant cells.

CONCLUSION

Our results demonstrated that, Schisandrin B, the primary lignan component of Schisandra chinensis, may exert its analgesic effect by acting on multiple ion channels, including glycine receptors, Nav1.7 channels, and Cav2.2 channels.

Exploring the therapeutic potential of cannabidiol for sleep deprivation-induced hyperalgesia

Hyperalgesia resulting from sleep deprivation (SD) poses a significant a global public health challenge with limited treatment options. The nucleus accumbens (NAc) plays a crucial role in the modulation of pain and sleep, with its activity regulated by two distinct types of medium spiny neurons (MSNs) expressing dopamine 1 or dopamine 2 (D1-or D2) receptors (referred to as D1-MSNs and D2-MSNs, respectively). However, the specific involvement of the NAc in SD-induced hyperalgesia remains uncertain. Cannabidiol (CBD), a nonpsychoactive phytocannabinoid, has demonstrated analgesic effects in clinical and preclinical studies. Nevertheless, its potency in addressing this particular issue remains to be determined. Here, we report that SD induced a pronounced pronociceptive effect attributed to the heightened intrinsic excitability of D2-MSNs within the NAc in Male C57BL/6N mice. CBD (30 mg/kg, i.p.) exhibited an anti-hyperalgesic effect. CBD significantly improved the thresholds for thermal and mechanical pain and increased wakefulness by reducing delta power. Additionally, CBD inhibited the intrinsic excitability of D2-MSNs both in vitro and in vivo. Bilateral microinjection of the selective D2 receptor antagonist raclopride into the NAc partially reversed the antinociceptive effect of CBD. Thus, these findings strongly suggested that SD activates NAc D2-MSNs, contributing heightened to pain sensitivity. CBD exhibits antinociceptive effects by activating D2R, thereby inhibiting the excitability of D2-MSNs and promoting wakefulness under SD conditions.

Deciphering the enigmatic symptoms of Pancoast tumors: Navigating the complex landscape of pain management-A case report

Pancoast tumors, also known as superior sulcus tumors, encompass a diverse spectrum of neoplasms that infiltrate the apex of the chest wall, yielding distinctive clinical presentations. One of the earliest signs of tumor growth is pain radiating to the upper limb, stemming from peripheral nerve involvement, which can mimic joint pain or spinal radicular irritation. In this case report, we present the clinical history of a 64-year-old female smoker who had previously been recommended for orthopedic elbow surgery due to epicondylitis. Subsequent to the development of additional symptoms and rigorous investigation, a Pancoast tumor was diagnosed. Furthermore, we discuss the characteristic treatment modalities available for Pancoast tumors, including pharmacological pain management and interventional strategies such as spinal cordotomy and spinal alcoholysis. This case underscores the significance of recognizing atypical presentations and emphasizes the importance of comprehensive evaluation in the diagnosis and management of Pancoast tumors.

Fear of movement and competence frustration mediate the relationship between pain catastrophising and physical function in people living with axSpA: an online cross-sectional survey

The objective of this study is to examine the contribution of pain catastrophising to Axial Spondyloarthritis (axSpA) patient's physical function and to test the mediating role of fear of movement, and uniquely, the contribution of competence frustration to the fear-avoidance model. Participants (N = 98, 70% female, M age = 45.62, SD 12.16) completed an online survey (December 2020-May 2021) distributed in the United Kingdom via the National Axial Spondyloarthritis Society (n ≈ 3500; NASS, 2019). The PROCESS SPSS macro was used to test three mediation models using percentile bootstrap 95% confidence intervals (PBCI). A significant indirect effect on the relationship between pain and physical function via fear of movement (β = 0.10, 95% PBCI = 0.030-0.183) was observed (Model 1). Model 2 showed the relationship between pain catastrophising and physical function to be significantly mediated by fear of movement (β = 0.16, 95% PBCI = 0.005-0.322). Finally, Model 3 showed a significant indirect effect on the relationship between pain catastrophising and physical function via competence frustration (β = 0.15, 95% PBCI = 0.014-0.309) but not through fear of movement (β = 0.062, 95% PBCI = - 0.134 to 0.248). To our knowledge, this is the first study to examine and demonstrate the unique contribution of competence need frustration to the Fear-avoidance model in people that live with axSpA. Identifying modifiable factors that contribute to disease outcomes such as physical function can improve the care and quality of life for people living with a disease currently without a cure.

Effectiveness of virtual reality on pain and anxiety in patients undergoing cardiac procedures: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Cardiac procedures often induce pain and anxiety in patients, adversely impacting recovery. Pharmachological approaches have limitations, prompting exploration of innovative digital solutions like virtual reality (VR). Although early evidence suggests a potential favourable benefit with VR, it remains unclear whether the implementation of this technology can improve pain and anxiety. We aimed to assess by a systematic review and meta-analysis the effectiveness of VR in alleviating anxiety and pain on patients undergoing cardiac procedures.

METHODS

Our study adhered to the PRISMA method and was registered in PROSPERO under the code CRD42024504563. The search was carried out in the PubMed, Web of Science, Scopus, and the Cochrane Library databases in January 2024. Four randomized controlled trials were included (a total of 382 patients). Risk of bias was employed to assess the quality of individual studies, and a random-effects model was utilized to examine the overall effect.

RESULTS

The results showed that VR, when compared to the standard of care, had a statistically significant impact on anxiety (SMD = -0.51, 95 % CI: -0.86 to -0.16, p = 0.004), with a heterogeneity I2 = 57 %. VR did not show a significant difference in terms of pain when compared to standard care (SMD= -0.34, 95 % CI: -0.75 to -0.07, p = 0.10). The included trials exhibited small sample sizes, substantial heterogeneity, and variations in VR technology types, lengths, and frequencies.

CONCLUSIONS

VR effectively lowers anxiety levels in patients undergoing cardiac procedures, however, did not show a statistically significant difference on pain.

Updating beliefs about pain following advice: Trustworthiness of social advice predicts pain expectations and experience

Prior expectations influence pain experience. These expectations, in turn, rely on prior pain experience, but they may also be socially influenced. Yet, most research has focused on self rather than social expectations about pain, and hardly any studies examined their combined effects on pain. Here, we adopted a Bayesian learning perspective to investigate how explicitly communicated social expectations ('advice about pain tolerance') affect own pain expectations, and ultimately pain tolerance, under varying conditions of social epistemic uncertainty (trustworthiness of the advice). N = 72 female participants took part in a coldpressor (cold water) task before (self-learning baseline) and after (socially-influenced learning) receiving advice about their likely pain tolerance from a confederate, the trustworthiness of whom was experimentally manipulated. We used path analysis to test the hypothesis that social advice from a highly trustworthy confederate would influence participants' expectations about pain more than advice from a less trustworthy source, and that the degree of this social influence would in turn predict pain tolerance. We further used a simplified, Bayesian learning, computational approach for explicit belief updating to examine the role of latent parameters of precision optimisation in how participants subsequently changed their future pain expectations (prospective posterior beliefs) based on the combined effect of the confederate's advice on their own pain expectations, and their own task experience. Results confirmed that participants adjusted their pain expectations towards the confederate's advice more in the high- vs. low-trustworthiness condition, and this advice taking predicted their pain tolerance. Furthermore, the confederate's trustworthiness influenced how participants weighted the confederate's advice in relation to their own expectations and task experience in forming prospective posterior beliefs. When participants received advice from a less trustworthy confederate, their own sensory experience was weighted more highly than their socially-influenced prior expectations. Thus, explicit social advice appears to impact pain by influencing one's own pain expectations, but low social trustworthiness leads to these expectations becoming more malleable to novel, sensory learning.

Pavlovian-to-instrumental transfer in individuals with chronic pain

Avoidance of pain has been argued to be key factor leading pain events to chronic disability. In this respect, research has focused on investigating the working mechanisms of avoidance's acquisition. Avoidance of painful stimuli has been traditionally studied using a combination of Pavlovian and Instrumental procedures. However, such approach seems to go against real-life scenarios where avoidance is commonly acquired more readily. Using a novel pain avoidance paradigm, we tested whether pain avoidance can be installed in absence of associations between a cue and pain omission, and whether such avoidance differs between pain patients and healthy controls. Participants first learned to avoid painful stimuli by pressing a grip bar. Then, they passively encountered pairings of one geometrical shape with pain and of another geometrical shape without pain. Lastly, participants encountered the geometrical shapes while being able to use the grip bar. Results showed that participants pressed the bar more vigorously when encountering the previously pain-related shape compared to the pain-unrelated shape. This effect did not seem to differ between pain patients and healthy control. Our study could inspire a new way in measuring avoidance in pain, possibly paving the way to better understanding how avoidance is installed in chronic pain.

Linguistic markers of anxiety and depression in Somatic Symptom and Related Disorders: Observational study of a digital intervention

BACKGROUND

Somatic Symptom and Related Disorders (SSRD), including chronic pain, result in frequent primary care visits, depression and anxiety symptoms, and diminished quality of life. Treatment access remains limited due to structural barriers and functional impairment. Digital delivery offers to improve access and enables transcript analysis via Natural Language Processing (NLP) to inform treatment. Therefore, we investigated asynchronous message-delivered SSRD treatment, and used NLP methods to identify symptom reduction markers from emotional valence.

METHODS

173 individuals diagnosed with SSRD received interventions from licensed therapists via messaging 5 days/week for 8 weeks. Depression and anxiety symptoms were measured with the PHQ-9 and GAD-7 from baseline every three weeks. Symptoms trajectories were identified using unsupervised random forest clustering. Emotional valence expressed and use of emotional words were extracted from patients' de-identified transcripts, respectively using VADER and NCR Lexicon. Valence differences were examined using logistic regression.

RESULTS

Two subpopulations were identified showing symptoms Improvement (n = 72; 41.62 %) and non-response (n = 101; 58.38 %). Improvement patients expressed more positive valence in the first week of treatment (OR = 1.84, CI: 1.12-3.02; p = .015) and were less likely to express negative valence by the end of treatment (OR = 0.05; CI: 0.30-0.83; p = .008). Non-response patients used more negative valence words, including pain.

LIMITATIONS

Findings were derived from observational data obtained during an ecological intervention, without the inclusion of a control group.

CONCLUSIONS

NLP identified linguistic markers distinguishing changes in anxiety and depression symptoms over treatment. Digital interventions offer new forms of delivery and provide the opportunity to automatically collect data for linguistic analysis.

Innovations in Stroke Recovery and Rehabilitation: Poststroke Pain

Pain can be a significant barrier to a stroke survivors' functional recovery and can also lead to a decreased quality of life. Common pain conditions after stroke include headache, musculoskeletal pain, spasticity-related pain, complex regional pain syndrome, and central poststroke pain. This review investigates the evidence of diagnostic and management guidelines for various pain syndromes after stroke and identifies opportunities for future research to advance the field of poststroke pain.

Exploring the impact of trauma-adapted yoga in forensic psychiatry

The specialized field of forensic psychiatry deals with the care of criminal offenders who suffer from severe mental disorders. As this field is positioned at the intersection of illness, crime, and security, it poses complex challenges. While high-quality clinical studies in forensic psychiatry settings are limited, recent investigations have suggested yoga as a complementary clinical tool within correctional environments. This report of a quasi-experimental study examines the impact of a 10-week trauma-adapted yoga intervention on mental health, antisocial and aggressive behaviors, pain perception, cravings, and character maturity among 56 patients in various forensic psychiatry clinics across Sweden. In the current study, the yoga group demonstrated noteworthy reductions in negative affect states, anxiety, phobic anxiety, paranoid ideations, interpersonal sensitivity, hostility, and overall psychological distress. These reductions were not observed in the comparison group. Additionally, the yoga group exhibited a significant decrease in pain frequency and strengthened self-directedness. However, there were no significant changes in aggressive, antisocial, or self-harm behaviors or cravings in either group. The between-group analyses did not yield significant results, except for pain intensity. The trauma-adapted yoga intervention implemented within forensic psychiatry settings shows feasibility and results in multiple positive changes in patients' health.

TRPV1: Receptor structure, activation, modulation and role in neuro-immune interactions and pain

In the 1990s, the identification of a non-selective ion channel, especially responsive to capsaicin, revolutionized the studies of somatosensation and pain that were to follow. The TRPV1 channel is expressed mainly in neuronal cells, more specifically, in sensory neurons responsible for the perception of noxious stimuli. However, its presence has also been detected in other non-neuronal cells, such as immune cells, β- pancreatic cells, muscle cells and adipocytes. Activation of the channel occurs in response to a wide range of stimuli, such as noxious heat, low pH, gasses, toxins, endocannabinoids, lipid-derived endovanilloid, and chemical agents, such as capsaicin and resiniferatoxin. This activation results in an influx of cations through the channel pore, especially calcium. Intracellular calcium triggers different responses in sensory neurons. Dephosphorylation of the TRPV1 channel leads to its desensitization, which disrupts its function, while its phosphorylation increases the channel's sensitization and contributes to the channel's rehabilitation after desensitization. Kinases, phosphoinositides, and calmodulin are the main signaling pathways responsible for the channel's regulation. Thus, in this review we provide an overview of TRPV1 discovery, its tissue expression as well as on the mechanisms by which TRPV1 activation (directly or indirectly) induces pain in different disease models.

Factors associated with a negative Patient Acceptable Symptom State (PASS) response with intrauterine device placement: A retrospective survey of HER Salt Lake participants

OBJECTIVES

In an established cohort of HER Salt Lake Contraceptive Initiative participants with a prior intrauterine device (IUD) placement, we sought to (1) define the proportion of participants who reported a negative Patient Acceptable Symptom State (PASS) response, (2) explore factors associated with an unacceptable PASS response, and (3) identify pain management preferences for IUD placement.

STUDY DESIGN

A retrospective survey was sent to 1440 HER Salt Lake IUD users. A PASS question queried IUD placement pain experience acceptability. We explored associations between an unacceptable PASS response and sociodemographic, reproductive and other individual characteristics using t-tests, chi-square tests, and multivariable logistic regression.

RESULTS

Of those surveyed, 620 responded (43%), and 41.6% reported an unacceptable PASS response. Those with an unacceptable PASS response reported a significantly higher experienced pain level (79.2 mm vs 51.8 mm; p < 0.01) than those with an acceptable response, were more likely to have an anxiety diagnosis (47.7% vs 37.1%; p < 0.01), and have a trauma history (33.7% vs 25.1%; p = 0.02). Most patients were not offered pain control options, but 29.4% used ibuprofen and 25.3% had a support person. Regardless of PASS response, if offered, 59.0% desired numbing medication, 56.8% ibuprofen, 51% heating pad, 33.2% support person, and 31.8% anti-anxiety medication, among others. In our multivariable logistic regression model, higher pain was associated with unacceptable PASS response (OR 1.07, 95% CI 1.05-1.08; p < 0.01).

CONCLUSIONS

The common finding of unacceptable pain experiences with IUD placement may cause negative perceptions of an otherwise desirable method. Incorporation of the PASS response into IUD pain management studies could expand our pain experience understanding.

IMPLICATIONS

IUD placement resulted in unacceptable pain experiences for 41.6% of respondents. Screening for anxiety and trauma history could identify at-risk patients to individualize pain management strategies. Incorporation of the PASS into future IUD pain management studies could result in a more comprehensive, patient-centered measure of patient experiences.

Obesity and tobacco smoking are independently associated with poor patient-reported outcomes in SLE: a cross-sectional study

We investigated associations of obesity and tobacco smoking with health-related quality of life (HRQoL), pain, fatigue, and functional impairment in systemic lupus erythematosus (SLE). Furthermore, we explored whether there was an effect modification between these two factors. We included adult SLE patients from the Linköping University Hospital (n = 325) in the present cross-sectional analysis. We further included population-based controls and performed cardinality matching to balance age and sex distributions with cases (n = 224). HRQoL was assessed with the EQ-5D index score; pain, fatigue, and overall SLE-related health state with visual analogue scales (VAS; 0 [best] to 100 [worst]); and functional impairment with the HAQ-DI. Unacceptable outcomes were defined as VAS scores corresponding to the 90th percentile derived from the matched controls. SLE patients reported worse scores than controls in all measures, and approximately 30% experienced unacceptable outcomes. When compared with normal-weight, obese SLE patients reported lower HRQoL, and greater functional impairment and risk of unacceptable pain (OR: 3.2; 95% CI 1.6-6.7) and fatigue (OR: 2.1; 95% CI 1.0-4.3). Similarly, the current smokers reported higher levels of functional impairment and a greater risk of unacceptable pain (OR: 3.8; 95% CI 1.8-8.2) and fatigue (OR: 2.8; 95% CI 1.3-5.9) than never smokers. The associations were independent of age, sex, disease duration, disease activity, and organ damage. There was no evidence of a synergistic effect between increased BMI and smoking on any outcome. In summary, obesity and smoking are risk factors for unacceptable patient-reported outcomes in SLE, regardless of clinical activity.

Optimising recovery after perineal trauma: Implementation of an evidence-based patient-centred care and clinical practice guideline

BACKGROUND

Perineal trauma and pain can affect the quality of life of women who experience vaginal birth.

AIM

To investigate the effect of perineal care and pain management on women's postpartum recovery.

METHODS

This was a Quasi-experimental study. In Phase 1 women were treated using our old postnatal perineal care management guideline. In Phase 2 an updated guideline was introduced (regular administration of icepacks and analgesia during the first 24-48 h postpartum). During Phase 1, pregnant women planning a vaginal birth completed a baseline questionnaire. Those who sustained perineal trauma completed a survey at 24-48 h, seven days and 12 weeks after birth. In Phase 2 we continued recruiting participants, using the same procedure, and investigated the efficacy of pain relief approaches using the new guideline.

RESULTS

In Phase 1, 111 women (Group 1), and Phase 2, 146 women (Group 2) were recruited. No statistically significant differences were found between the two groups in terms of the women's pain catastrophising, their partner's responses to pain behaviours, or birth outcomes. At 24-48 h and seven days postpartum, women in Group 2 were less likely than women in Group 1 to be bothered by back or perineal pain, headache, sleeping difficulties and dizziness (p < 0.05). More women in Group 2 received regular paracetamol and perineal icepacks during their hospital stay, with less use of oxycodone in Group 2 than Group 1.

CONCLUSION

The implementation of the guideline's recommendations was associated with decrease back and perineal pain, headache, sleeping difficulties and dizziness during the first seven days postpartum.

Experimental and pharmacoinformatic approaches unveil the neuropharmacological and analgesic potential of chloroform fraction of Roktoshirinchi (Achyranthes ferruginea Roxb.)

ETHNOPHARMACOLOGICAL RELEVANCE

Achyranthes ferruginea (A. ferruginea) Roxb. is a common plant used in traditional medicine in Asia and Africa. It has a variety of local names, including "Gulmanci" in Nigeria, "Dangar" in Pakistan, "Thola" in Ethiopia, and "Roktoshirinchi" in Bangladesh. It is edible and has several ethnomedical uses for a wide range of illnesses, including hysteria, dropsy, constipation, piles, boils, asthma, and shigellosis. However, the neuropharmacological and analgesic potential of A. ferruginea remains uninvestigated.

AIM OF THE STUDY

To assess the neuropharmacological and analgesic potential of A. ferruginea through a multifaceted approach encompassing both experimental and computational models.

MATERIALS AND METHODS

Methanol was used to extract the leaves of A. ferruginea. It was then fractionated with low to high polar solvents (n-hexane, chloroform, ethyl acetate, and water) to get different fractions, including chloroform fraction (CLF). The study selected CLF at different doses and conducted advanced chemical element and proximate analyses, as well as phytochemical profiling using GC-MS. Toxicological studies were done at 300 μg per rat per day for 14 days. Cholinesterase inhibitory potential was checked using an in-vitro colorimetric assay. Acetic acid-induced writhing (AAWT) and formalin-induced licking tests (FILT) were used to assess anti-nociceptive effects. The forced swim test (FST), tail suspension test (TST), elevated plus maze (EPM), hole board test (HBT), and light and dark box test (LDB) were among the behavioral tests used to assess depression and anxiolytic activity. Network pharmacology-based analysis was performed on selected compounds using the search tool for interacting chemicals-5 (STITCH 5), Swiss target prediction tool, and search tool for the retrieval of interacting genes and proteins (STRING) database to link their role with genes involved in neurological disorders through gene ontology and reactome analysis.

RESULTS

Qualitative chemical element analysis revealed the presence of 15 elements, including Na, K, Ca, Mg, P, and Zn. The moisture content, ash value, and organic matter were found to be 11.12, 11.03, and 88.97%, respectively. GC-MS data revealed that the CLF possesses 25 phytoconstituents. Toxicological studies suggested the CLF has no effects on normal growth, hematological and biochemical parameters, or cellular organs after 14 days at 300 μg per rat. The CLF markedly reduced the activity of both acetylcholinesterase and butyrylcholinesterase (IC50: 56.22 and 13.22 μg/mL, respectively). Promising dose-dependent analgesic activity (p < 0.05) was observed in chemically-induced pain models. The TST and FST showed a dose-dependent substantial reduction in immobility time due to the CLF. Treatment with CLF notably increased the number of open arm entries and time spent in the EPM test at doses of 200 and 400 mg/kg b.w. The CLF showed significant anxiolytic activity at 200 mg/kg b.w. in the HBT test, whereas a similar activity was observed at 400 mg/kg b.w. in the EPM test. A notable increase in the amount of time spent in the light compartment was observed in the LDB test by mice treated with CLF, suggesting an anxiolytic effect. A network pharmacology study demonstrated the relationship between the phytochemicals and a number of targets, such as PPARA, PPARG, CHRM1, and HTR2, which are connected to the shown bioactivities.

CONCLUSIONS

This study demonstrated the safety of A. ferruginea and its efficacy in attenuating cholinesterase inhibitory activity, central and peripheral pain, anxiety, and depression, warranting further exploration of its therapeutic potential.

Confirmation of pain-related neuromodulation mechanism of Bushen Zhuangjin Decoction on knee osteoarthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Bushen Zhuangjin Decoction (BZD) are an herbal compound commonly used to treat osteoarthritis (OA) in China.

AIM OF THE STUDY

This study aimed to verify the mechanism of Bushen Zhuangjin Decoction in relieving the pain of knee osteoarthritis.

MATERIALS AND METHODS

Network pharmacology evaluation was used to discover the potential targets of BZD to relieve pain in KOA. The therapeutic effects of BZD treatment on KOA pain using histomorphology, behavioral assessments, suspension chip analysis, and ultra-high performance liquid chromatography/tandem mass spectrometry (UHPLC-MS/MS) assays. The functional magnetic resonance imaging was used to explore the effects of BZD treatment on brain function associated to KOA.

RESULTS

Network pharmacological analysis revealed the association between the analgesic effect of BZD on KOA and the pain signaling neurotransmitter 5-HT. Subsequently, we conducted experiments to verify the therapeutic effect of BZD on pain in KOA animal models. Behavioral tests demonstrated that the pain threshold of knee osteoarthritis rats decreased in PWT and PWL, but BZD was able to increase the pain threshold. Histopathological staining indicated thinning of the cartilage layer and sparse trabeculae in the subchondral bone. Suspension chip analysis revealed a significant increase in pro-inflammatory factors of IL-1α, IL-5, IL-12, IL-17A, RANTES, TNF-α and M-CSF in KOA, along with a significant decrease in anti-inflammatory factor of IL-13. However, BZD treatment decreased the expression of pro-inflammatory factors and increased the content of anti-inflammatory factor. UHPLC-MS/MS analysis showed a significant decrease in the serum levels of GABA, E, GSH, Kyn, Met, and VMA in KOA, which were significantly increased by BZD. Conversely, the serum levels of TrpA, TyrA, Spd, and BALa were significantly increased in KOA and significantly decreased by BZD. ELISA and Western blot analysis showed increased expression of subchondral bone pain-related neuropeptides SP, CGRP, TH, NPY, VEGFA, 5-HT3 in KOA, which were decreased in BZD. Functional magnetic resonance imaging demonstrated that BZD exerts its therapeutic effect on KOA by modulating the activity and functional connections of the cortex, hypothalamus, and hippocampus.

CONCLUSIONS

This study confirmed the significant role of pain-related neuromodulation mechanisms in the analgesic therapy of BZD and provides a theoretical foundation for using BZD as a traditional Chinese medical treatment for KOA pain.

Durable Effects of Acupuncture for Knee Osteoarthritis: A Systematic Review and Meta-analysis

PURPOSE OF REVIEW

Knee osteoarthritis (KOA) is a degenerative joint disease which can result in chronic pain and disability. The current interventions available for KOA often fail to provide long-lasting effects, highlighting the need for new treatment options that can offer durable benefits. Previous studies have suggested the efficacy of acupuncture for knee osteoarthritis (KOA) with its durability remaining uncertain. In this review, we aimed to investigate the durability of the efficacy after completion of treatment.

RECENT FINDINGS

We performed thorough searches of PubMed, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials from inception to November 4, 2023. The outcomes were assessed at all available time points after completion of treatment. Primary outcomes were changes from baseline in pain and function measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function subscales. Secondary outcomes included response rate, overall pain, the WOMAC stiffness subscale, total WOMAC index, and physical and mental health components of 12/36-item Short-Form Health Survey. A total of 10 randomized controlled trials (RCTs) involving 3221 participants were included. Pooled estimates suggested that acupuncture may offer potential improvements in function and overall pain for 4.5 months post-treatment versus sham acupuncture (SA). Acupuncture may provide durable clinically important pain relief and functional improvement up to 5 months post-treatment versus usual care, and up to 6 months post-treatment versus diclofenac. For acupuncture versus no treatment, one trial with large sample size indicated that improvements in pain and function persisted for 3 months post-treatment, while the other trial reported that significant pain reduction and functional improvement were only observed at the end of the treatment, not at 9 months post-treatment. However, acupuncture as adjunct to exercise-based physical therapy (EPT) showed no superiority to SA as an adjunct to EPT or EPT alone up to 11.25 months after completion of treatment. Acupuncture may provide pain alleviation and functional improvements in KOA patients for 3 to 6 months after completion of treatment with a good safety profile.

The effect of high-intensity laser therapy on pain and lower extremity function in patellofemoral pain syndrome: a single-blind randomized controlled trial

Patellofemoral pain syndrome (PFPS) is a set of symptoms that negatively affect the daily life activities of the individual, leading to functional disability and significant loss of labor, especially in young adults. PFPS is usually due to weakness of the vastus medialis obliquus (VMO) resulting in abnormal patellar tracking and pain. Our study aims to compare the efficacy of high-intensity laser therapy (HILT) on pain and lower extremity function in the treatment of PFPS with different electrophysical agents (EPAs). The study was designed as a single-blind randomized controlled trial. Forty-five people with PFPS (aged 25-45 years) were included in the study. The patients were randomly divided into three groups and a total of ten sessions of treatment were administered to all three groups for 2 weeks, 5 days a week. High-intensity laser (HILT) and exercise program were applied to group 1. Ultrasound (US), transcutaneous electrical nerve stimulation (TENS), and exercise program were applied to group 2. In group 3, US, interferential current (IFC), and exercise program were applied. Both groups underwent three evaluations: pre-treatment, post-treatment, and 12 weeks after treatment. Outcome measures included the visual analog scale for pain severity (VAS), knee flexion range of motion (FROM), Q angle, pain threshold, muscle strength of quadriceps and hamstring, Kujala patellofemoral scoring, lower extremity functional scale (LEFS), and Timed Up and Go Test (TUG). The ANOVA was used for comparing the data of the groups, and two-way repeated measure ANOVA was used to compare at the pre-post and post-intervention 3rd month. The LSD and Bonferroni post hoc tests were also used to identify the between-group differences. Groups 2 and 3 were statistically effective in pain and functionality (p < 0.05). Group 1 was found to be statistically more effective than other groups in reducing pain (95% confidence interval (CI), 0.000/0.000; p = 0.000), increasing knee flexion angle (95% CI, 127.524/135.809; p = 0.000), and increasing lower extremity function (95% CI, 75.970/79.362; p = 0.000). This study indicated that high-intensity laser therapy was found to be a more effective method in the treatment of patellofemoral pain syndrome after 3 months of follow-up compared to US-TENS combination and US-interferential current combination treatments. Also, HILT can be used as an effective method in combination with an appropriate exercise program including vastus medialis strengthening to reduce pain and increase functionality in the patients with PFPS.

Effects of PDE-3 inhibition in persistent post-traumatic headache: evidence of cAMP-dependent signaling

BACKGROUND

Phosphodiesterase 3 (PDE-3) inhibition have been implicated in the neurobiologic underpinnings of migraine. Considering the clinical similarities between migraine and persistent post-traumatic headache (PPTH), we aimed to ascertain whether PDE-3 inhibition can elicit migraine-like headache in persons with PPTH.

METHODS

We tested cilostazol, which inhibits PDE-3, in a randomized, double-blind, placebo-controlled, two-way crossover study involving persons with PPTH attributed to mild traumatic brain injury. The randomized participants were allocated to receive oral administration of either 200-mg cilostazol or placebo (calcium tablet) on two separate experiment days. The primary end point was the incidence of migraine-like headache during a 12-hour observation window post-ingestion. The secondary endpoint was the area under the curve (AUC) for reported headache intensity scores during the same observation window.

RESULTS

Twenty-one persons underwent randomization and completed both experiment days. The mean participants' age was 41.4 years, and most (n = 17) were females. During the 12-hour observation window, 14 (67%) of 21 participants developed migraine-like headache post-cilostazol, in contrast to three (14%) participants after placebo (P =.003). The headache intensity scores were higher post-cilostazol than after placebo (P <.001).

CONCLUSIONS

Our results provide novel evidence showing that PDE-3 inhibition can elicit migraine-like headache in persons with PPTH. Given that PDE-3 inhibition increases intracellular cAMP levels, our findings allude to the potential therapeutic value of targeting cAMP-dependent signaling pathways in the management of PPTH. Further investigations are imperative to substantiate these insights and delineate the importance of cAMP-dependent signaling pathways in the neurobiologic mechanisms underlying PPTH.

CLINICALTRIALS

GOV IDENTIFIER

NCT05595993.

Expression patterns of mechanosensitive ion channel PIEZOs in irreversible pulpitis

BACKGROUND

Mechanosensitive ion channel PIEZOs have been widely reported to involve inflammation and pain. This study aimed to clarify expression patterns of PIEZOs and their potential relations to irreversible pulpitis.

MATERIALS AND METHODS

Normal pulp tissues (n = 29) from patients with impacted third molars and inflamed pulp tissues (n = 23) from patients with irreversible pulpitis were collected. Pain levels were assessed using a numerical rating scale. PIEZO expressions were measured using real-time PCR and then confirmed using GEO datasets GSE77459, immunoblot, and immunohistochemistry staining. Correlations of PIEZO mRNA expression with inflammatory markers, pain markers, or clinical pain levels were evaluated using Spearman's correlation analysis. Univariate analysis was conducted to analyze PIEZO expressions based on pain description and clinical examinations of cold test, percussion, palpation, and bite test.

RESULTS

Compared with normal pulp tissues, mRNA expression levels of PIEZO1 were significantly increased in inflamed pulp tissues, while PIEZO2 was significantly decreased, which was further confirmed in GSE77459 and on a protein and histological level. The positive correlation of the mRNA expression levels between PIEZO1 and inflammatory markers, as well as between PIEZO2 and pain markers, was verified. PIEZO2 expression was also positively correlated with pain levels. Besides, irreversible pulpitis patients who reported continuous pain and who detected a positive response to cold stimulus exhibited a higher expression level of PIEZO2 in the inflamed pulp tissues. By contrast, patients reporting pain duration of more than one week showed a higher expression level of PIEZO1.

CONCLUSIONS

This study demonstrated the upregulation of PIEZO1 and the downregulation of PIEZO2 in irreversible pulpitis and revealed the potential relation of PIEZO1 and PIEZO2 to inflammation and pain. These findings suggested that PIEZOs might play critical roles in the progression of irreversible pulpitis and paved the way for further investigations aimed at novel therapies of irreversible pulpitis by targeting PIEZOs.

Opioid use disorder in pediatric populations: considerations for perioperative pain management and precision opioid analgesia

INTRODUCTION

Opioids are commonly used for perioperative analgesia, yet children still suffer high rates of severe post-surgical pain and opioid-related adverse effects. Persistent and severe acute surgical pain greatly increases the child's chances of chronic surgical pain, long-term opioid use, and opioid use disorder.

AREAS COVERED

Enhanced recovery after surgery (ERAS) protocols, are often inadequate in treating a child's severe surgical pain. Research suggests that 'older' and longer-acting opioids such as methadone are providing better methods to treat acute post-surgical pain. Studies indicate that lower repetitive methadone doses can decrease the incidence of chronic persistent surgical pain (CPSP). Ongoing research explore genetic components influencing severe surgical pain, inadequate opioid analgesia, and opioid use disorder. This new genetic research coupled with better utilization of opioids in the perioperative setting provides hope in personalizing surgical pain management, reducing pain, opioid use, adverse effects, and helping the fight against the opioid pandemic.

EXPERT OPINION

The opioid and analgesic pharmacogenomics approach can proactively 'tailor' a perioperative analgesic plan to each patient based on underlying polygenic risks. This transition from population-based knowledge of pain medicine to individual patient knowledge can transform acute pain medicine and greatly reduce the opioid epidemic's socioeconomic, personal, and psychological strains globally.

The role of orphan G protein-coupled receptors in pain

G protein-coupled receptors (GPCRs), which form the largest family of membrane protein receptors in humans, are highly complex signaling systems with intricate structures and dynamic conformations and locations. Among these receptors, a specific subset is referred to as orphan GPCRs (oGPCRs) and has garnered significant interest in pain research due to their role in both central and peripheral nervous system function. The diversity of GPCR functions is attributed to multiple factors, including allosteric modulators, signaling bias, oligomerization, constitutive signaling, and compartmentalized signaling. This review primarily focuses on the recent advances in oGPCR research on pain mechanisms, discussing the role of specific oGPCRs including GPR34, GPR37, GPR65, GPR83, GPR84, GPR85, GPR132, GPR151, GPR160, GPR171, GPR177, and GPR183. The orphan receptors among these receptors associated with central nervous system diseases are also briefly described. Understanding the functions of these oGPCRs can contribute not only to a deeper understanding of pain mechanisms but also offer a reference for discovering new targets for pain treatment.

Blocking the dopaminergic receptors within the hippocampal dentate gyrus reduced analgesic responses induced by restraint stress in the formalin test

Previous studies have shown that various receptors, including dopamine receptors, are expressed in the hippocampal dentate gyrus (DG). Besides, indicatively, dopamine receptors play an essential role in the modulation of pain perception. On the other hand, stressful experiences can produce analgesia, termed stress-induced analgesia (SIA). The current study examined the probable role of dopamine receptors within the DG in antinociception induced by restraint stress (RS). Ninety-seven male albino Wistar rats were unilaterally implanted with a cannula in the DG. Animals received intra-DG microinjections of SCH23390 or Sulpiride (0.25, 1, and 4 μg/rat) as D1-and D2-like dopamine receptor antagonists, respectively, five minutes before RS. Ten minutes after the end of the induction of RS for three hours, 50 μl 2.5% formalin was injected subcutaneously into the plantar surface of the hind paw to induce persistent inflammatory pain. Pain scores were evaluated at 5-minute intervals for 60 minutes. These findings showed that; exposure to RS for three hours produced SIA in both phases of the formalin test, while this RS-induced analgesia was attenuated in the early and late phases of the formalin test by intra-DG microinjection of SCH23390 and Sulpiride. The results of the present study suggested that both D1- and D2-like dopamine receptors in the DG have a considerable role in the induced analgesia by RS.

Impact of the COVID-19 pandemic on clinical and psychological aspects of temporomandibular disorders

BACKGROUND

The Coronavirus 2019 disease (COVID-19) caused drastic changes in people's lifestyle that affected TMD characteristics through its physical and psychological influences. The aim of this study was to define the clinical and psychological characteristics of a large group of well-defined TMD patients and seek their differences between before and during the COVID-19 pandemic to establish points of care to be emphasized in the post-pandemic era.

METHODS

TMD patients diagnosed by the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) aged ≥ 18 were analyzed. Samples between September, 2017 to July, 2019 (n = 455) and March, 2021 to June, 2022 (n = 338) were collected to represent before and during COVID-19, respectively. The Graded Chronic Pain Scale (GCPS) and Symptom Checklist-90-Revision (SCL-90-R) were used to evaluate disability levels and psychological status. Clinical indices were compared between COVID periods and factors related to higher pain levels were investigated according to pandemic period.

RESULTS

More patients reported pain on palpation of the masticatory muscles during the pandemic (p = 0.021) while the number decreased for neck muscles (p = 0.001) and TMJ (p < 0.001) areas. Patients reporting nocturnal bruxism (23.3-29.6%) and clenching (45.1-54.7%) significantly increased during the pandemic. TMD patients with pain without disability were more common during the pandemic regardless of pain intensity (p < 0.001). The number of patients expressing interference in daily activities decreased drastically during COVID-19 regardless of disability level (p < 0.001). Factors associated with higher than moderate pain intensity (CPI ≥ 50) were insomnia (odds ratio [OR] = 1.603, p = 0.047) and somatization (OR = 1.082, p < 0.001) before the pandemic. During the pandemic, age (OR = 1.024, p = 0.007), somatization (OR = 1.070, p = 0.006), and paranoid ideation (OR = 1.117, p = 0.003) were significantly associated with higher pain intensity.

CONCLUSIONS

The results of our study underline the importance of evaluating psychological profiles of TMD patients, especially somatization, paranoid ideation and psychoticism, in exceptional situations that may cause a change in individual mental status. This will lead to a better understanding of the individual TMD patient and help in planning personalized treatment strategies that will assist the patient in adjusting to changes occurring in special environments such as the COVID-19 pandemic.

Pain catastrophizing in rheumatic diseases: prevalence, origin, and implications

Pain is a crucial factor in rheumatic disorders, and reducing it is a primary goal of successful treatment. Adaptive pain-coping strategies can enhance this improvement, but maladaptive approaches such as pain catastrophizing may worsen overall patient well-being. This narrative review aims to provide a concise overview of the existing knowledge on pain catastrophizing in the most prevalent specific rheumatic disorders. The objective of this study was to improve understanding of this phenomenon and its implications, as well as to pinpoint potential directions for future research. We conducted searches in the MEDLINE/PubMed, SCOPUS, and DOAJ bibliography databases to identify articles related to pain catastrophizing in rheumatoid arthritis, psoriatic arthritis, axial spondylarthritis, systemic sclerosis, systemic lupus erythematosus, Sjögren's syndrome, juvenile idiopathic arthritis, and osteoarthritis (non-surgical treatment). Data extraction was performed on November 1, 2023. The investigators screened the identified articles to determine their relevance and whether they met the inclusion criteria. Following a bibliography search, which was further expanded by screening of citations and references, we included 156 records in the current review. The full-text analysis centred on pain catastrophizing, encompassing its prevalence, pathogenesis, and impact. The review established the role of catastrophizing in amplifying pain and diminishing various aspects of general well-being. Also, potential treatment approaches were discussed and summarised across the examined disorders. Pain catastrophizing is as a significant factor in rheumatic disorders. Its impact warrants further exploration through prospective controlled trials to enhance global patient outcomes.

Beyond the Surface: A Narrative Review Examining the Systemic Impacts of Recessive Dystrophic Epidermolysis Bullosa

Recessive dystrophic epidermolysis bullosa (RDEB) is a rare genetic disease resulting from inadequate type VII collagen (C7). Although recurrent skin blisters and wounds are the most apparent disease features, the impact of C7 loss is not confined to the skin and mucous membranes. RDEB is a systemic disease marred by chronic inflammation, fibrotic changes, pain, itch, and anemia, significantly impacting QOL and survival. In this narrative review, we summarize these systemic features of RDEB and promising research avenues to address them.

Intravenous administration of recombinant Phα1β: Antinociceptive properties and morphine tolerance reversal in a cancer-associated pain model

Cancer-related pain is considered one of the most prevalent symptoms for those affected by cancer, significantly influencing quality of life and treatment outcomes. Morphine is currently employed for analgesic treatment in this case, however, chronic use of this opioid is limited by the development of analgesic tolerance and adverse effects, such as digestive and neurological disorders. Alternative therapies, such as ion channel blockade, are explored. The toxin Phα1β has demonstrated efficacy in blocking calcium channels, making it a potential candidate for alleviating cancer-related pain. This study aims to assess the antinociceptive effects resulting from intravenous administration of the recombinant form of Phα1β (r-Phα1β) in an experimental model of cancer-related pain in mice, tolerant or not to morphine. The model of cancer-induced pain was used to evaluate these effects, with the injection of B16F10 cells, followed by the administration of the r-Phα1β, and evaluation of the mechanical threshold by the von Frey test. Also, adverse effects were assessed using a score scale, the rotarod, and open field tests. Results indicate that the administration of r-Phα1β provoked antinociception in animals with cancer-induced mechanical hyperalgesia, with or without morphine tolerance. Previous administration of r-Phα1β was able to recover the analgesic activity of morphine in animals tolerant to this opioid. r-Phα1β was proved safe for these parameters, as no adverse effects related to motor and behavioral activity were observed following intravenous administration. This study suggests that the concomitant use of morphine and r-Phα1β could be a viable strategy for pain modulation in cancer patients.

Effect of cognitive behavioral therapy on pain, knee function, and psychological status in patients after primary total knee arthroplasty: a systematic review and meta-analysis

OBJECTIVE

The clinical efficacy of cognitive behavioral therapy (CBT) after Total knee arthroplasty (TKA) is still controversial, and the purpose of this meta-analysis was to evaluate the effect of CBT on pain, knee function, and psychological status of patients after TKA.

METHODS

We systematically searched electronic databases such as CNKI, CBM, VIP, PubMed, Cochrane Library, and EMBASE for randomized controlled studies up to February 30, 2023. Screening against inclusion criteria to select valid studies and extract data. The quality of included studies was evaluated by the Cochrane Collaboration risk-of-bias 2 (RoB 2) tool for randomized trials. Statistical analysis of the data from this study was carried out using Stata 15.1 software.

RESULTS

Finally, our meta-analysis incorporated seven randomized controlled studies of high quality, including 608 patients. The findings of the meta-analysis demonstrated a noteworthy decrease in kinesiophobia levels during the early postoperative phase in the CBT group as compared to the usual care group (WMD = -6.35, 95% CI: -7.98 to -4.72, Z = 7.64, P < 0.001). However, no statistically significant difference between the CBT and usual care groups in terms of postoperative pain as well as knee function.

CONCLUSION

CBT may effectively reduce the level of kinesiophobia in the short term after TKA, but did not significantly relieve knee pain or improve knee function.

Prevalence of diagnosed and undiagnosed osteoarthrosis and associated factors in the adult general Spanish population

OBJECTIVE

To determine the prevalence and related factors of diagnosed osteoarthrosis (DO) and undiagnosed osteoarthrosis (UO) in the general Spanish adult population.

SETTING

Cross-sectional study with data from the Spanish National Health Survey 2017.

PARTICIPANTS

N=23,089 adults. Three groups of people were defined: DO, UO, and no osteoarthrosis (NO).

MAIN MEASUREMENTS

Sociodemographic information, lifestyle (tobacco, alcohol, physical activity, body mass index) and health factors (intensity of pain, pain drug consumption, mental health, self-perceived health status, pain involvement in daily living) were collected. Descriptive and bivariate analyses were performed, and a multinomial logistic regression model for the factors associated with each group.

RESULTS

The prevalence of DO was 22.4% (95%CI=21.8;22.9) and 0.9% (95%CI=0.8;1) of UO. With respect to NO, risk factors for DO and UO included higher pain levels and pain drug consumption. Better self-perceived health status was inversely related with both. More pain involvement in daily living was associated with increased risk of DO, but reduced risk of UO.

CONCLUSIONS

The prevalence of DO and UO was similar to that reported in Europe, but slightly higher than in low/middle-income countries. It was more prevalent in females, older people, people with worse perceived health status and worse mental health. Higher pain levels and pain drug consumption were risk factors for DO and UO. Better self-perceived health status was protective. Pain involvement in daily living was a risk factor for DO, but protective for UO. Different public health strategies should be considered in view of this.

SimSAARlabim study - The role magic tricks play in reducing pain and stress in children

BACKGROUND

Vaccination is an essential preventative medical intervention, but needle fearandinjection painmay result in vaccination hesistancy.

STUDY PURPOSE

To assess the role of magic tricks - no trick vs. one trick ("disappearing handkerchief trick") vs. three tricks ("disappearing handkerchief trick", "jumping rubber band trick", and "disappearing ring trick") - performed by a professional magician and pediatrician during routine vaccination in reducing discomfort/pain and the stress response (heart rate, visual analogue scale (VAS), and biomarkers (cortisol, Immunoglobulin A (IgA), α-amylase, and overall protein concentration in saliva before and after vaccination).

PATIENTS AND METHODS

Randomized controlled trial (RCT) in healthy children aged 6-11 years undergoing routine vaccination in an outpatient setting.

RESULTS

50 children (26 female) were enrolled (no trick: n = 17, 1 trick: n = 16, 3 tricks: n = 17) with a median age of 6.9 years (range: 5.3-10.8 years). We detected no significant differences among the three groups in their stress reponse (heart rate before and after vaccination and cortisol, IgA, α-amylase, and overall protein concentrations in saliva before and after vaccination) or regarding pain assessment using the VAS.

CONCLUSIONS

Although children undergoing routine outpatient vaccination appeared to enjoy a magician's presence, the concomitant performance of magic tricks revealed no significant effect on the stress response.

Is the Central Sensitization Inventory (CSI) associated with quantitative sensory testing (QST)? A systematic review and meta-analysis

Central sensitization (CS) involves an amplification of neural processing within the central nervous system that can result in widespread pain patterns and hypersensitivity to stimuli. The Central Sensitization Inventory (CSI) and various quantitative sensory testing (QST) methods purport to assess clinical markers of CS. The purpose of this systematic review and meta-analysis was to summarize and quantify the associations between total CSI scores and QST measures from previous studies. A systematic search identified 39 unique studies that were deemed eligible for the systematic review and 33 studies for meta-analyses (with 3314 subjects and 154 effect sizes), including five QST modalities: conditioned pain modulation, temporal summation, pressure pain threshold, heat pain threshold, and cold pain threshold. The meta-analysis yielded statistically significant CSI-QST correlations in total subject samples for all five QST modalities. The strongest associations were identified between CSI scores and pain threshold testing, especially pressure pain threshold, in which 51% of effects sizes, from 29 studies and 3071 subjects, were determined to be in a medium to large range.

Comparative study on the efficacy of pregabalin versus limaprost in patients with lumbar spinal stenosis: A prospective, randomized controlled trial

BACKGROUND

Patients with Lumbar Spinal Stenosis (LSS) typically complain of back pain and leg pain. These symptoms reduce the quality of life and also cause sleep disturbances. This study compares pregabalin and limaprost's efficacy in LSS for pain, disability, quality of life, and sleep, aiming to offer insights for medication selection.

METHODS

This study was designed as a prospective, randomized, single-center, single-blinded, clinical superiority trial targeting patients with LSS. For 6 weeks, 111 patients per group were administered medication following a standard regimen, after which patient-reported outcomes were measured. The primary outcome was the Visual Analogue Scale (VAS) for back and leg pain, and the secondary outcomes included the Oswestry Disability Index (ODI), European Quality of Life 5 Dimensions (EQ-5D), and sleep quality.

RESULTS

After 6 weeks of medication, there were significant improvements over time in the primary outcome, VAS for back pain and leg pain, in both groups, but no significant difference between the two groups. Similarly, for the secondary outcomes, ODI and EQ-5D, both groups showed significant improvements, yet there was no significant difference between them. In the subgroup analysis targeting poor sleepers (Pittsburgh sleep quality index, PSQI > 5), both groups also exhibited significant improvements in sleep quality, but again, there was no significant difference between the groups.

CONCLUSIONS

Efficacy of pregabalin, limaprost in back and leg pain, ODI, EQ-5D, and sleep quality, but there was no significant difference between the two groups. Thus, it is advisable to prescribe based on individual drug responses and potential complications.

Pain care for children with cognitive impairment: A parent-nurse partnership

PURPOSE

To explore nurses' experiences of establishing partnerships with parents for pain care of hospitalized children with cognitive impairment (CI) and identify related facilitators and barriers.

DESIGN AND METHODS

In this qualitative, interpretive descriptive study, individual semi-structured interviews were conducted via videoconferencing with pediatric nurses from inpatient wards in a Canadian pediatric quaternary hospital. Verbatim transcripts were analyzed using an inductive, data-driven thematic analysis approach.

RESULTS

Eleven nurses were interviewed. The overarching theme was Assessing Pain as an Outsider: "A Complete Guessing Game". Seven major themes were identified.: Relying on Parent Expertise for Pain Assessment, Brainstorming with Parents for Pain Treatment, Supporting Parents as Advocates for Pain Care, Individualizing Pain Care with Parents, Involving the Child in Pain Care: A Spectrum, Barriers to Partnership in Pain Care and Facilitators to Partnership in Pain Care.

CONCLUSIONS

Nurses described the many ways they involve parents as partners in pain care. However, nurses shared strong feelings of uncertainty associated with pain care in children with CI. Consequently, nurses felt the need to rely on parents for appropriately assessing and treating pain in children with CI. Findings highlighted the practice and education gaps that may contribute to nurses' uncertainty and reliance on parents.

PRACTICE IMPLICATIONS

By identifying related practice and education gaps, healthcare organizations can implement strategies to further support nurses in establishing partnerships and potentially optimize pain care practices.

Physical therapy interventions for people experiencing homelessness to improve pain and self-perceived health status

BACKGROUND

Homeless shelters have emerged as components of the social services network, playing an important role in providing health care to the homeless population. The aim of this study was to evaluate an individualized physical therapy intervention for people experiencing homelessness and to determine the relationship between self-perceived variables.

METHODS

Pre and post study, setting at the "Santa y Real Hermandad de Nuestra Señora del Refugio y Piedad" homeless shelter in Zaragoza, Spain. Participants were people experiencing homelessness with musculoskeletal disorders who attended a physical therapy service at shelter facilities. A physical therapy program was implemented including health education, exercise and manual therapy, electrotherapy, thermotherapy and bandaging. Demographic variables (age and gender), nationality, employment situation, educational level, pain location, number of painful areas, feeling of loneliness (3-Item Loneliness Scale; values from 3 to 9), pain intensity (Numerical Pain Rating Scale [NPRS]; from 0 to 10) and self-perceived health (Clinical Global Impression [CGI]; from 1 to 7).

RESULTS

Sixty-four homeless people (age of 46.4 ± 10.9 years) participated in the study. Musculoskeletal pain was reported by 98.4% of subjects, with moderate pain intensities (6.1), and 48.4% presenting with pain at multiple sites. Perceptions of loneliness were low (3.7 ± 2.5) and self-perceived health status was moderately ill (3.5 ± 1.7). Positive significant correlations were identified between pain intensity and self-perceived health. The average number of sessions was 1.5 (± 0.8), with manual therapy (35.6%) followed by health education (23.5%) being the most frequently used techniques. Both pain and self-perceived health improved after treatment, even following a brief intervention.

CONCLUSIONS

This study demonstrates the potentially negative impact of untreated pain on the self-perceived health of homeless individuals with musculoskeletal disorders that should be targeted for consideration. The findings suggest that a paradigm shift in pain management, including a physical therapy service in shelters, is needed to address the rehabilitation demands of these individuals in a real-life context. This study was approved by the Aragon Ethics Committee (PI19/438) and performed according to the Transparent Reporting of Evaluations with Nonrandomized Designs (TREND) statement.

Surgical Patients' Evaluation of Pain Management Quality and Surgical Nurses' Pain-Related Knowledge and Attitudes

PURPOSE

The present study was aimed at investigating the quality of pain management evaluated by inpatients in surgical clinics, and pain-related knowledge and attitudes of nurses working in surgical clinics, surgical units, or emergency services.

METHODS

The study was conducted as a descriptive and cross-sectional study. The study data were collected from inpatients in surgical clinics (N = 306), and from nurses working in surgical clinics, surgical units, or emergency services (N = 57) between January 2020 and September 2020. The Revised American Pain Society Patient Outcome Questionnaire (APS-POQ-R) and Nurses' Knowledge and Attitudes Survey Regarding Pain (NKASRP) were the tools used for data collection.

RESULTS

The mean scores the participants obtained from the severity of worst pain, pain relief, and satisfaction with pain treatment components of the APS-POQ-R were 6.14 ± 2.59, 59.28 ± 22.26, and 8.99 ± 1.62, respectively. There were significant differences between many components of the APS-POQ-R in terms of such variables as age, sex, undergoing previous surgery, presence of pain before surgery, surgery performed, and type of anesthesia (p < .05). The mean score the participants obtained from the NKASRP was 15.35 ± 3.87.

CONCLUSIONS

It was concluded that the patients' pain was relieved moderately, that they were very highly satisfied with pain treatment, and that the nurses' pain-related knowledge and attitude levels were below the moderate level.

CLINICAL IMPLICATIONS

Nurses should support patients whose in-bed activities were prevented due to pain, involve them in pain treatment decisions, advise them about pain treatment options, and encourage them to use nonpharmacological methods.

Time-course of pain and salivary opiorphin release in response to oral capsaicin differ in burning mouth syndrome patients, temporomandibular disorders patients and control subjects

OBJECTIVES

Opiorphin is an analgesic peptide released by salivary glands and capsaicin an agonist of TRPV1 receptors eliciting burning sensations. The primary objective of this study was to assess opiorphin release after stimulation of the tongue by capsaicin (STC). The secondary objectives were to compare opiorphin release after STC in 3 groups of subjects [healthy (CTRL), Burning Mouth Syndrome (BMS), painful Temporomandibular disorders (TMDp)] and pain evoked by STC in these 3 groups.

MATERIALS AND METHODS

Salivary opiorphin was assessed with high-performance liquid chromatography at 3 different time points (baseline, after 5 min and 20 min of STC). Pain was self-reported on a (0-10) numeric rating scale.

RESULTS

Three groups (N = 16) of adults were recruited at the Clinical Hospital Centre and School of Dental Medicine in Zagreb. Opiorphin levels were higher (1) in TMDp compared to CTRL in 1st (2.23 ± 1.72 pg/ul vs. 0.67 ± 0.44 pg/ul, p = 0.002) and 3rd sampling (2.44 ± 2.01 pg/ul vs. 0.74 ± 0.52 pg/ul, p = 0.020) and (2) within BMS group at 3rd sampling vs. baseline (p < 0.025). Pain scores were higher in BMS compared to TMDp (p < 0.025) and CTRL (p < 0.025).

CONCLUSION

This study evidenced (1) a differential basal amount of opiorphin in two pain conditions and control subjects (2) a differential kinetic of release of opiorphin after STC in CTRL, BMS and TMDp (3) a differential pain perception after STC in BMS and TMDp vs. CTRL, which can provide a readout for animal models.

CLINICAL RELEVANCE

The specific regulation of opiorphin release in patients with orofacial painful conditions provides valuable insights for clinicians and researchers in physiology and pathology and encourages further research in this area.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04694274. Registered on 01/05/2021.

The use of prescription medications and non-prescription medications during lactation in a prospective Canadian cohort study

BACKGROUND

A lack of safety data on postpartum medication use presents a potential barrier to breastfeeding and may result in infant exposure to medications in breastmilk. The type and extent of medication use by lactating women requires investigation.

METHODS

Data were collected from the CHILD Cohort Study which enrolled pregnant women across Canada between 2008 and 2012. Participants completed questionnaires regarding medications and non-prescription medications used and breastfeeding status at 3, 6 and 12 months postpartum. Medications, along with self-reported reasons for medication use, were categorized by ontologies [hierarchical controlled vocabulary] as part of a large-scale curation effort to enable more robust investigations of reasons for medication use.

RESULTS

A total of 3542 mother-infant dyads were recruited to the CHILD study. Breastfeeding rates were 87.4%, 75.3%, 45.5% at 3, 6 and 12 months respectively. About 40% of women who were breastfeeding at 3 months used at least one prescription medication during the first three months postpartum; this proportion decreased over time to 29.5% % at 6 months and 32.8% at 12 months. The most commonly used prescription medication by breastfeeding women was domperidone at 3 months (9.0%, n = 229/2540) and 6 months (5.6%, n = 109/1948), and norethisterone at 12 months (4.1%, n = 48/1180). The vast majority of domperidone use by breastfeeding women (97.3%) was for lactation purposes which is off-label (signifying unapproved use of an approved medication). Non-prescription medications were more often used among breastfeeding than non-breastfeeding women (67.6% versus 48.9% at 3 months, p < 0.0001), The most commonly used non-prescription medications were multivitamins and Vitamin D at 3, 6 and 12 months postpartum.

CONCLUSIONS

In Canada, medication use is common postpartum; 40% of breastfeeding women use prescription medications in the first 3 months postpartum. A diverse range of medications were used, with many women taking more than one prescription and non-prescription medicines. The most commonly used prescription medication by breastfeeding women were domperidone for off-label lactation support, signalling a need for more data on the efficacy of domperidone for this indication. This data should inform research priorities and communication strategies developed to optimize care during lactation.

Considerations beyond spine pain: do different co-occurring lower body joint pains differentially influence physical function and quality of life ratings?

BACKGROUND

Patients seeking medical care for back pain often have coexisting painful joints and the effects of different combinations and number of coexisting pain sites (hip, knee, foot/ankle) to back pain on physical function domains and quality of life rating are not yet established. The purpose of this study was to determine the differences in functional outcomes and QOL among individuals with back pain who have concurrent additional pain sites or no pain sites.

METHODS

Data from the Osteoarthritis Initiative (OAI) cohort were used for this cross-sectional analysis. Men and women aged 45-79 years with back pain were binned into nine groups by presence or not of coexisting hip, knee, ankle/foot pain and combinations of these sites (N = 1,642). Healthy controls reported no joint pain. Main outcomes included Knee Injury and Osteoarthritis Outcome score (KOOS; quality of life and function-sports-and-recreation), Western Ontario McMaster Universities Osteoarthritis Index (WOMAC; Activities of Daily Living, Pain), Medical Outcomes Short Form-12 (SF-12) Physical Component score, and self-reported function in last 7-30 days (lifting 25-pound objects, housework). 20-m and 400-m walk times and gait speed and repeated chair rise test times were collected.

RESULTS

Compared to back pain alone, pain at all five sites was associated with 39%-86% worse KOOS, WOMAC, and SF-12 scores (p < .0001). Back-Hip and Back-Knee did not produce worse scores than Back pain alone, but Back-Hip-Knee and Back-Knee-Ankle/Foot did. The 20-m, 400-m walk, and repeated chair times were worse among individuals with pain at all five sites. Additional hip and knee sites to back pain, but not ankle/foot, worsened performance-based walk times and chair rise scores.

CONCLUSIONS

The number and type of coexistent lower body musculoskeletal pain among patients with back pain may be associated with perceived and performance-based assessments. Management plans that efficiently simultaneously address back and additional coexistent pain sites may maximize treatment functional benefits, address patient functional goals in life and mitigate disability.

Postradiation trismus in head and neck cancer survivors: a qualitative study of effects on life, rehabilitation, used coping strategies and support from the healthcare system

PURPOSE

This study aimed to explore the experiences of head and neck cancer (HNC) survivors with postradiation trismus, specifically how oncological treatment affected their lives, rehabilitation, use of coping strategies, and healthcare experiences.

METHODS

A qualitative descriptive approach was used and semi-structured interviews of 10 HNC survivors with postradiation trismus were conducted 6-30 months after completing oncological treatment. The interviews were transcribed verbatim and analyzed by qualitative content analysis.

RESULTS

The analysis of interviews yielded four main categories: Bodily symptoms, Effects on life, Support from the healthcare system, and Strategies to handle life and symptoms. Participants reported ongoing problems with xerostomia, dysgeusia, eating, and limited physical fitness. Pain related to trismus was not a major issue in this cohort. Participants expressed limitations in their social lives due to their eating difficulties, yet a sense of thankfulness for life and overall satisfaction with the healthcare they received. Psychological and practical coping strategies developed by the participants were also revealed.

CONCLUSION

The results highlight areas of unmet need among HNC survivors that healthcare providers can target by establishing multi-professional teams dedicated to individualizing post-cancer rehabilitation care.

The efficacy of pericapsular nerve group block for reducing pain and opioid consumption after total hip arthroplasty: a systematic review and meta-analysis

BACKGROUND

Pericapsular nerve group block (PENG) is an emerging regional anesthesia technique for hip surgery. However, its efficacy in total hip arthroplasty (THA) isn't well defined. We perform this meta-analysis aiming to assess the effect of Pericapsular nerve group block on pain control and morphine consumption in patients with total hip arthroplasty.

METHODS

We searched four electronic databases (Pubmed, Embase, Cochrane Library, and Web of Science dated from 2018 to October 2023) for published eligible randomized controlled trials (RCTs) comparing PENG with placebo (no block/sham block) after THA. The outcome measurements consisted of pain score, opioid consumption, Time to first opioid, and postoperative complications. All data analyses were performed using STATA 12.0.

RESULTS

Five RCTs comprising 808 participants were included. Our meta-analysis showed that there were significant differences between two groups in terms of pain score in PACU (WMD =  - 0.598, 95% CI [- 0.886, - 0.310], P < 0.001), pain score at 6 h (WMD =  - 0.614, 95% CI [- 0.835, - 0.392], P < 0.001) and time to first opioid (WMD = 5.214, 95% CI [4.545, 5.883], P < 0.001). However, no significant differences were revealed from the pain score at 24 h after THA (WMD =  - 0.924, 95% CI [- 1.929, 0.081], P = 0.072). Meanwhile, the meta-analysis indicated that PENG significantly reduced 24-h opioid consumption (WMD =  - 6.168, 95% CI [- 6.667, - 5.668], P < 0.001) and 48-h opioid consumption (WMD =  - 7.171, 95% CI [- 8.994, - 5.348], P < 0.001).

CONCLUSION

Pericapsular nerve group block was effective for pain control up to postoperative 6 h and extending the time to the first opioid after THA. Moreover, it reduced postoperative opioid consumption when compared with a placebo group. Due to the high heterogeneity of the pain score after 24 h and the low-quality evidence, more high-quality RCTs are required to draw a definitive conclusion about pain control.

The relationship between gender, psychosocial factors, pain, health literacy and health-related quality of life in parents of Norwegian adolescents one year into the COVID-19 pandemic

BACKGROUND

Stress impacts healthy behaviours and may influence life and health-related quality of life (HRQOL). A stressful event occurred when the COVID-19 pandemic hit in March 2020. The present study aims to explore possible gender differences in stress, psychosocial factors (self-efficacy, self-esteem, loneliness), pain, HL, and HRQOL in parents of adolescents one year into the COVID-19 pandemic, and to explore possible associations between gender, demographic and psychosocial factors, pain, HL, and HRQOL.

METHODS

Parents of adolescents aged 16-17 took part in the study from January to February 2021, when the COVID-19 pandemic was ongoing. Data on socio-demographics, stress, self-efficacy, self-esteem, pain, HL, loneliness, and HRQOL were collected. HRQOL was assessed using RAND-36.

RESULTS

Among the 320 parents from the general population, the mean age was 47.6 (standard deviation (SD) = 4.6) years, 81% were mothers, 79% were married or cohabiting, 81% had a university degree, and the majority worked full time (78%) or part time (13%). The average pain score was low, 0.48 (95% CI [0.43-0.54]). However, 50% of the parents reported persistent pain and more mothers reported persistent pain compared to fathers (53% vs. 37%). The parents' mean (SD) score for RAND-36 was 52.1 (95% CI [51.2-53.0]) for the physical component summary (PCS) score and 51.0 (95% CI [50.0-52.1]) for the mental component summary (MCS) score. Mothers reported significantly lower scores for all the eight RAND-36 domains and the PCS and MCS scores. Adjusting for gender, age, living condition, education, pain, HL, self-efficacy and loneliness, we revealed no associations between stress and RAND-36-PCS. University education of four years or more was positively associated (B = 3.29, 95% CI: [0.78-5.80]) with RAND-36-PCS, while persistent pain was negatively associated (B = -7.13, CI: [-9.20- -5.06]). We identified a strong negative association between RAND-36-MCS and stress (B = -43.11, CI: [-48.83- -37.38]) and a positive association with older age (B = 0.21, CI: [ 0.04, 0.39)].

CONCLUSION

One year into the COVID-19 pandemic, we identified a strong negative association between stress and mental HRQOL, while pain was strongly negatively associated with physical HRQOL.

Effect of epidural dexmedetomidine in single-dose combined with ropivacaine for cesarean section

BACKGROUND

Dexmedetomidine has arousal sedation and analgesic effects. We hypothesize that epidural dexmedetomidine in single-dose combined with ropivacaine improves the experience of parturient undergoing cesarean section under epidural anesthesia. This study is to investigate the effect of 0.5 µg/kg epidural dexmedetomidine combined with epidural anesthesia (EA) in parturients undergoing cesarean section.

METHODS

A total of 92 parturients were randomly divided into Group R (receiveing epidural ropivacaine alone) Group RD (receiveing epidural ropivacaine with 0.5 µg/kg dexmedetomidine). The primary outcome and second outcome will be intraoperative NRS pain scores and Ramsay Sedation Scale.

RESULTS

All 92 parturients were included in the analysis. The NRS were significantly lower in Group RD compared to Group R at all observation timepoint (P > 0.05). Higher Ramsay Sedation Scale was found in Group RD compared to Group R (P < 0.001). No parturient has experienced sedation score of 4 and above. No significant difference regarding the incidence of hypotension, bradycardia and nausea or vomiting, Apgar scores and the overall satisfaction with anesthesia was found between Group R and Group RD (P > 0.05).

CONCLUSION

Epidural dexmedetomidine of 0.5 µg/kg added slightly extra analgesic effect to ropivacaine in EA for cesarean section. The sedation of 0.5 µg/kg epidural dexmedetomidine did not cause mother-baby bonding deficit. Satisfaction with anesthesia wasn't significantly improved by epidural dexmedetomidine of 0.5 µg/kg. No additional side effect allows larger dose of epidural dexmedetomidine attempt.

TRIAL REGISTRATION

This study was registered at www.chictr.org.cn (ChiCTR2000038853).

A new insight into material basis of rhizoma Paridis saponins in alleviating pain

ETHNOPHARMACOLOGICAL RELEVANCE

Paris polyphylla, as a traditional Chinese herbal medicine, was often used to relieve inflammation and pain. Rhizoma Paridis saponins (RPS) as the main active components of Paris polyphylla have excellent analgesic effects.

AIM OF THE STUDY

Determine the analgesic material basis of RPS.

MATERIALS AND METHODS

LC-MS/MS was used to analyze RPS, plasma after intravenous injection of RPS, and oral administration of RPS. H22 plantar pain model was established to explore the analgesic material basis of RPS. Moreover, correlation analysis, network pharmacology, RT-PCR and molecular docking were applied in this research.

RESULTS

RPS had dose-dependently analgesic effects in acetic acid- and formalin-induced pain models. LC-MS/MS detection indicated that diosgenin as the metabolite of RPS mainly distributed in brain tissues. The addition of antibiotics increased the anti-tumor effect of RPS, but reduced its analgesic effect. Network pharmacology, RT-PCR and molecular docking showed that diosgenin exerted its analgesic effect through SRC and Rap1 signaling pathway.

CONCLUSION

Diosgenin exhibited analgesic effects, while saponins had good anti-tumor effects in RPS. This discovery provided a better indication for the later application of RPS in anti-tumor and analgesic settings.

Pain-related single nucleotide polymorphisms: association with lumbar spinal stenosis patient experience and non-surgical treatment outcomes

PURPOSE

Lumbar spinal stenosis (LSS) is common in our aging population resulting in pain and functional impairment. Recent advances in pain research have identified several single nucleotide polymorphisms (SNP) associated with inter-individual symptom and treatment response. The goal of the current study was to investigate the association of SNPs in Neuropeptide Y (NPY) and Catechol-O-methyltransferase (COMT) with pain, function, and treatment outcomes in Lumbar spinal stenosis (LSS) patients receiving non-surgical treatments.

METHODS

An exploratory observational biomarker study was performed ancillary to a previously published clinical trial evaluating three different non-surgical treatments for LSS. Saliva samples were obtained for single nucleotide polymorphism genotyping and blood samples were collected for NPY protein. Data on pain and function collected as part of the clinical trial at baseline, 2 and 6 months were examined for association with known polymorphisms in NPY and COMT.

RESULTS

Subjects with the NPY rs16147 TT genotype exhibited higher baseline symptom severity but also a higher likelihood of responding to non-surgical treatments. Subjects with the COMT rs4680 GG genotype also exhibited higher baseline symptom severity but did not demonstrate greater response to treatment.

CONCLUSIONS

NPY rs16147 and COMT rs4680 are important potential biomarkers associated with pain and function. NPY genotype may be useful in predicting response to non-surgical treatments in older adults with LSS.

Nerve Preparation and Recordings for Pharmacological Tests of Sensory and Nociceptive Fiber Conduction Ex Vivo

Measuring signal propagation through nerves is a classical electrophysiological technique established decades ago to evaluate sensory and motor functions in the nervous system. The whole-nerve preparation provides a valuable model to investigate nerve function ex vivo; however, it requires specific knowledge to ensure successful and stable measurements. Although the methodology for sciatic nerve recordings has long existed, a method for reliable and long-lasting recordings from myelinated and non-myelinated (nociceptive) fibers still needs to be adapted for pharmacological testing. This protocol takes benefits from epineurium sheath removal for pharmacological tests and provides a detailed description of how to make accurate nerve preparations, from the dissection and handling of nerves to epineurium cleaning, fabrication of adaptable suction electrodes for appropriate fiber stimulation and recordings, setting of electrophysiological protocols for compound action potential (CAP) recordings to distinguish between myelinated and non-myelinated (nociceptive) fibers, and finally to the analysis of the datasets of CAP components. We also demonstrate the feasibility of CAP recordings from individual branches in epineurium-free nerve preparations and provide clues to help retain nerve viability and maintain stable recordings over time. Although a sciatic nerve preparation was used here, the methodology can be applied to other nerve-type preparations. Key features • Detailed and simplified protocol for peripheral nerve preparation for recording sensory inputs ex vivo. • Recordings from myelinated and non-myelinated (nociceptive) fibers can be performed hours after nerve preparation. • The protocol involves the epineurium removal to facilitate drug permeability into nerve tissue for pharmacological tests. • The protocol allows physiological and pathological studies (pain/chronic pain conditions).

How to differentiate induced pluripotent stem cells into sensory neurons for disease modelling: a functional assessment

BACKGROUND

Human induced pluripotent stem cell (iPSC)-derived peripheral sensory neurons present a valuable tool to model human diseases and are a source for applications in drug discovery and regenerative medicine. Clinically, peripheral sensory neuropathies can result in maladies ranging from a complete loss of pain to severe painful neuropathic disorders. Sensory neurons are located in the dorsal root ganglion and are comprised of functionally diverse neuronal types. Low efficiency, reproducibility concerns, variations arising due to genetic factors and time needed to generate functionally mature neuronal populations from iPSCs remain key challenges to study human nociception in vitro. Here, we report a detailed functional characterization of iPSC-derived sensory neurons with an accelerated differentiation protocol ("Anatomic" protocol) compared to the most commonly used small molecule approach ("Chambers" protocol). Anatomic's commercially available RealDRG™ were further characterized for both functional and expression phenotyping of key nociceptor markers.

METHODS

Multiple iPSC clones derived from different reprogramming methods, genetics, age, and somatic cell sources were used to generate sensory neurons. Manual patch clamp was used to functionally characterize both control and patient-derived neurons. High throughput techniques were further used to demonstrate that RealDRGs™ derived from the Anatomic protocol are amenable to high throughput technologies for disease modelling.

RESULTS

The Anatomic protocol rendered a purer culture without the use of mitomycin C to suppress non-neuronal outgrowth, while Chambers differentiations yielded a mix of cell types. Chambers protocol results in predominantly tonic firing when compared to Anatomic protocol. Patient-derived nociceptors displayed higher frequency firing compared to control subject with both, Chambers and Anatomic differentiation approaches, underlining their potential use for clinical phenotyping as a disease-in-a-dish model. RealDRG™ sensory neurons show heterogeneity of nociceptive markers indicating that the cells may be useful as a humanized model system for translational studies.

CONCLUSIONS

We validated the efficiency of two differentiation protocols and their potential application for functional assessment and thus understanding the disease mechanisms from patients suffering from pain disorders. We propose that both differentiation methods can be further exploited for understanding mechanisms and development of novel treatments in pain disorders.

Evaluation of reduced ('Lite') compression versus brief bandaging to manage post-operative pain after total knee arthroplasty surgery; a single-centre randomised controlled trial

PURPOSE

Investigate efficacy of reduced compression bandage for the control of pain after total knee arthroplasty.

PATIENTS & METHODS

Prospective, single-centre, randomised controlled trial involving data for 56 out of 94 consented patients; 29 standard care versus 27 Andoflex TLC Calamine Lite. Comparison of standard care (non-compression bandage applied for up to one day) versus Andoflex TLC Calamine Lite (25-30 mmHg) two-layer compression bandage worn for five days. Outcomes measured with validated pain (McGill, 10-cm visual scale) and functionality (KOOS) tools.

RESULTS

At day 5 post-surgery, the median pain level was 3.0 cm vs 4.0 cm (p-value 0.47, Mann-Whitney U test) respectively. Generic pain levels, pain types, and knee functionality did not differ between the interventions at days 3/5/12 and week 6 post-surgery. An exception was the degree of 'tender' pain at day 12, which was significantly lower in the Andoflex TLC Calamine Lite arm (p-value 0.041, Mann-Whitney U test). Binary logistic regression analysis showed that application of Andoflex TLC Calamine Lite, administration of oxycodone, and male sex were all significantly associated with less 'tender' pain.

CONCLUSION

Reduced compression bandaging does not affect overall pain levels post knee arthroplasty surgery, but may alleviate pain experienced as 'tender', highlighting the different types of pain that may be experienced. Patients' need for, and the use of, opioid medication (oxycodone) is a significant confounding variable when assessing adjuvant therapy to control pain. The applicability of reduced compression bandaging may therefore be limited and is less efficient than medical pain control.