Pain Inhibition Research Articles

Methanolic Extract of Edible Lasia spinosa Rhizome: A Potential Natural Source of Analgesic, Diuretic, and Thrombolytic Agents

ABSTRACT Kohila (Lasia spinosa), a marshy plant with spiky rhizomes, is traditionally used in ethnomedicine to treat ailments like uterine cancer, arthritis, inflammation, and gastrointestinal disorders while also being consumed as a vegetable. This study evaluated the phytochemical composition and bioactive potential of methanolic rhizome extract (LSR-ME) through qualitative and quantitative screening, along with analgesic, diuretic, and thrombolytic activity assays. Phytochemical analysis confirmed the presence of flavonoids, alkaloids, glycosides, tannins, and carbohydrates. In analgesic tests, LSR-ME at 400 mg kg−1 showed significant pain inhibition (47.73% in acetic acid–induced writhing and 37.83% in formalin–induced writhing). It also demonstrated notable diuretic effects, with Lipschitz values confirming its activity (p < .05). The extract exhibited strong, dose-dependent thrombolytic activity (p < .001). Molecular docking studies have highlighted meridinol’s superior binding efficiency (−8.5 to −9.2 kcal mol−1) and high affinity for ligand–protein interactions. Computational AdmetSAR analysis further supported the therapeutic potential of the identified compounds. Overall, the findings from in vivo, in vitro, and molecular docking studies indicate that LSR-ME has promising analgesic, diuretic, and thrombolytic properties, warranting further investigation into its medicinal applications. These results validate traditional uses of L. spinosa and highlight its potential as a source of bioactive compounds for drug development.

A review on microneedle patch as a delivery system for proteins/peptides and their applications in transdermal inflammation suppression.

A review on microneedle patch as a delivery system for proteins/peptides and their applications in transdermal inflammation suppression.

Potential of zoledronate for treating diffuse sclerosing osteomyelitis of the mandible in adult patients.

Diffuse sclerosing osteomyelitis (DSO) is a rare nonbacterial bone disease associated with recurrent pain and swelling, and its pathogenesis remains unknown. Despite the absence of an established treatment for DSO, bisphosphonates have recently been considered effective in managing this condition. However, the use of zoledronate is off-label, with limited reported cases. Therefore, this study aimed to investigate the effects of zoledronate on pain suppression in DSO. This single-arm retrospective study evaluated adult patients diagnosed with mandibular DSO and treated with zoledronate. Patient demographics, pain suppression effect, recurrence, number of zoledronate administration, adverse reactions to zoledronate, and imaging findings were investigated. The study included 18 patients (median age of 59.5years). Zoledronate effectively suppressed pain in all patients, with a median duration of effect onset of 1day. Symptom recurrence was observed in 66.7% of patients, with a median time of 29months from the first zoledronate administration to recurrence. Zoledronate was administered multiple times to 44.7% of patients. The median duration of response was 80months for patients who experienced relief after a single administration of zoledronate compared to 32months for those who received multiple administrations (p < 0.001). Adverse reactions, including flu-like symptoms, were observed in 72.2% of the patients, and no medication-related osteonecrosis of the jaw was observed during the follow-up period. Zoledronate is a relatively safe and effective treatment option for DSO of the mandible. Key Points • Zoledronate effectively suppresses pain in mandibular diffuse sclerosing osteomyelitis. • All condylar lesions recurred after zoledronate administration. • Patients with mandibular canal enlargement required multiple doses of zoledronate. • Adverse reactions to zoledronate administration were minor.

Celastrol loaded nanocomplex for painless tumor therapy via YAP inhibition

Cancer-related pain is prevalent and severely impairs patients’ quality of life. However, conventional cancer therapies primarily target tumor cell destruction, often overlooking the management of cancer pain. Thus, there is an immediate necessity to develop therapeutic agents that can both suppress tumor growth and alleviate cancer pain. In this study, we report a celastrol (CEL)-based nanocomposites (PDA-BSA-MnO2-CEL) for pain-less cancer immunotherapy. Results from in vitro and in vivo experiments demonstrate the efficacy and mechanism of the nanocomposites in pain-less immunotherapy. MnO2 and CEL induce immunogenic cell death (ICD), mediating immunotherapy. Additionally, CEL significantly reduces the secretion of the immunosuppressive factor Yes-associated protein (YAP) within the tumor microenvironment, thereby enhancing the efficacy of immunotherapy. The downregulation of YAP leads to reduced expression of vascular endothelial growth factor (VEGF), inhibiting tumor growth and decreasing activation of the pain-associated VEGF receptor 1 (VEGFR1), thus providing an analgesic effect. Moreover, CEL reduces inflammatory pain by lowering levels of inflammatory factors in tumors. The design of this nanocomposites system integrates immunotherapy with cancer pain inhibition, offering a novel approach to patient-centered tumor therapy.

Alpha-2 receptor mediates the endogenous antagonistic regulation of itch and pain via descending noradrenaline pathway from the locus coeruleus.

Alpha-2 receptor mediates the endogenous antagonistic regulation of itch and pain via descending noradrenaline pathway from the locus coeruleus.

Endogenous pain modulation is not different in basketball or volleyball athletes with patellar tendinopathy compared to asymptomatic athletic controls.

Patellar tendinopathy is highly prevalent in basketball and volleyball athletes. Despite pain being the main symptom reported, underlying mechanisms are unclear. Our primary aim was to compare endogenous pain inhibition using a conditioned pain modulation protocol in basketball and volleyball athletes with patellar tendinopathy to asymptomatic athletic controls. Our secondary aim was to compare endogenous pain facilitation using a temporal summation protocol. Cross-sectional case-control. Twenty-six athletes and 19 asymptomatic controls participated. We calculated the difference in PPT at the patellar tendon over the most painful site (pain site), the ipsilateral tibialis anterior (regional site), and the contralateral elbow lateral epicondyle (remote site), before and after immersion of the hand (ipsilateral to pain site) in painful cold-water. PPT change was used to quantify endogenous pain inhibition. Participants rated pain on a numerical rating scale (NRS; 0=no pain to 10=worst pain imaginable) at five, 20, 60 and 120s during the cold-water immersion task. Change in NRS from five to 20s quantified temporal summation. Median symptom duration in our patellar tendinopathy group was 39 (IQR 22.5-55.5) months, and 85% experienced symptoms bilaterally. We did not observe alterations in endogenous pain inhibition at any site, or in temporal summation, in athletes with patellar tendinopathy compared to controls (p>0.05). Our findings indicate that altered central nervous system function is not a predominate feature contributing to pain in jumping athletes with patellar tendinopathy. Accordingly, clinicians should view pain as being of a local tissue source if targeting this symptom.

Conditioned pain modulation elicited through manual pressure techniques on the cervical spine: a crossover study.

Manual pressure techniques are commonly employed as a therapeutic approach for individuals experiencing musculoskeletal pain. The painful nature of these techniques suggests that a central mechanism known as conditioned pain modulation (CPM) might play a role. This study tested whether a painful manual pressure technique (MPT) reduces pain sensitivity partly by eliciting a CPM effect. This crossover study examined 3 different conditioning stimuli: (1) a cold pressor test (CPT) with the contralateral hand submerged in a cold water bath, (2) painful MPT, and (3) sham-MPT on suboccipital muscles. We measured their effect on pain sensitivity using pressure pain thresholds at 3 locations: locally (suboccipital muscles), regionally (trapezius muscle), and remotely (tibialis anterior muscle). In 63 healthy participants, no significant differences were found between the painful MPT and CPT on the pressure pain thresholds at all test locations: locally, -11 kPa (95% CI: 3 to -25); regionally, -15 kPa (95% CI: 10 to -39); and remotely, -24 kPa (95% CI: 55 to -7). Manual pressure technique compared to sham-MPT showed significant differences in the suboccipital muscles, -20.04 kPa (95% CI: -6.45 to -34.63) and the trapezius muscle, -38.24 (95% CI: -13.97 to -62.5) but no significant difference at the tibialis anterior muscle, -17.5 kPa (95% CI: 13.9 to -48.91). Painful MPTs applied at the suboccipital muscles reduce pain sensitivity at all sites, similar to the CPT, indicating CPM activation. Central pain inhibition might contribute to the effect of painful MPT in healthy people.

In vivo and in silico analysis of anti inflammatory, antipyretic and analgesic activity of methanolic extract of Nigella sativa.

Nigella Sativa (N. sativa) belongs to the family of Ranunculaceae and is an annual herb which is also known as black cumin or black seed. Since ancient times N. sativa has been used because of its widespread therapeutic properties which has been proven effective in respiratory, cardiovascular, gastrointestinal, inflammatory conditions and in inflammation. This study investigates the antiinflammatory, antipyretic, and analgesic properties of Nigella sativa (N. sativa) methanol extract using albino rats (n = 36). Diclofenac and paracetamol were used as standard medications in the trial, and the four concentrations of the methanolic extract (250, 500, 1000, and 2000mg/kg) were tested for their effects on inflammation, pain, and fever. The methanolic extract of N. sativa seeds showed significant inhibition of fever (96%), inflammation (89%), and pain (85%). In addition, bioactive compounds in the seeds, including thymol, p-cymene, and limonene, were examined through in-silico studies. Ligand molecules and proteins associated with anti-inflammatory, analgesic, and antipyretic effects were 1DFN, 1A06, and 3LN0, respectively. The molecular docking results indicated significant binding interactions, with effective binding energy values corresponding to analgesic, antipyretic, and anti-inflammatory properties. Both in-silico and in-vivo results demonstrate the efficacy of N. sativa methanol extract in alleviating pain, inflammation, and fever.

Decoding the mechanism of proanthocyanidins in central analgesia: redox regulation and KCNK3 blockade.

Neuropathic pain causes enduring physical discomfort and emotional distress. Conventional pharmacological treatments often provide restricted relief and may result in undesirable side effects, posing a substantial clinical challenge. Peripheral and spinal redox homeostasis plays an important role in pain processing and perception. However, the roles of oxidative stress and antioxidants in pain and analgesia on the cortical region during chronic pain remains obscure. Here we focus on the ventrolateral orbital cortex (VLO), a brain region associated with pain severity and involved in pain inhibition. Using a spared nerve injury mouse model, we observed the notable reactive oxygen species (ROS)-mediated suppression of the excitability of pyramidal cells (PYRVLO) in the VLO. Nasal application or microinjection of the natural antioxidants proanthocyanidins (PACs) to the VLO specifically increased the activity of PYRVLO and induced a significant analgesic effect. Mechanistically, PACs activate PYRVLO by inhibiting distinct potassium channels in different ways: (1) by scavenging ROS to reduce ROS-sensitive voltage-gated potassium currents and (2) by acting as a channel blocker through direct binding to the cap structure of KCNK3 to inhibit the leak potassium current (Ileak). These results reveal the role of cortical oxidative stress in central hyperalgesia and elucidate the mechanism and potential translational significance of PACs in central analgesia. These findings suggest that the effects of PACs extend beyond their commonly assumed antioxidant or anti-inflammatory effects.

Evaluation of Zoledronate for Pain Suppression in Diffuse Sclerosing Osteomyelitis of the Mandible: Protocol for a Prospective, Single-Arm Interventional Study.

Diffuse sclerosing osteomyelitis (DSO) is a non-bacterial osteomyelitis that occurs infrequently and is characterized by recurrent severe pain, swelling of the mandible, and trismus. To date, no effective treatment has been established. Bisphosphonates have been suggested as an efficacious treatment for DSO; however, no prospective studies have examined the effect of bisphosphonate treatment in adults with DSO. This study aims to evaluate the effect of zoledronate on pain suppression in patients with DSO. This is a single-center, exploratory, single-arm, prospective interventional study. The participants will include eight patients with DSO of the mandible. The primary endpoint is the change in pain levels before and after zoledronate administration. The secondary endpoints are assessing the efficacy of the clinical course, imaging changes, and safety monitoring. Patients will be enrolled if they are deemed eligible following screening tests and will receive only one 4.0 mg intravenous dose of zoledronate within seven days of enrollment. Study participants will be followed up at one, four, 12, 24, and 48 weeks post-dose or at discontinuation after zoledronate administration. This study is the first prospective trial to evaluate the effect of administering a single dose of zoledronate on pain suppression in patients with DSO. We believe this study will lead to the conclusion that zoledronate is an effective treatment for DSO.

Top-down control of the descending pain modulatory system drives placebo analgesia.

In placebo analgesia, prior experience and expectations lead to pain suppression by the administration of an inert substance, but causal evidence for its neural basis is lacking. To identify the underlying neural circuits, we reverse-translated a conditioned placebo protocol from humans to mice. Surprisingly, the placebo effect suppresses both nociception and unconditioned emotional-motivational pain-related behavior. Descending pain modulatory neurons in the periaqueductal gray (PAG) are critical for both morphine and placebo antinociception. The placebo effect depends on input to the PAG from the medial prefrontal and anterior cingulate cortices, but not anterior insular cortex. Conditioning enhances noxious stimulus-evoked endogenous opioid release in the PAG to produce analgesia. Our results suggest that cortical control of the descending pain modulatory system (DPMS) is gated by rapid endogenous opioid signaling in the PAG during placebo trials. This study bridges clinical and preclinical research, establishing a central role for the DPMS in placebo analgesia.

Uji Efektivitas Analgetik Ekstrak Etanol Daun Sirih Merah (Piper crocatum) pada Mencit Putih (Mus musculus L) yang Diinduksi dengan Asam Asetat

This study explored the analgesic effectiveness of ethanol extract of red betel leaf (Piper crocatum) in white rats (Mus musculus L.) induced with acetic acid. A total of 15 rats were divided into five groups with different treatments, and the number of twitching movements as a pain response was measured for one hour. The extract was prepared using 96% ethanol solvent, and the analgesic effect was analyzed using the writhing test method. The results showed that the extract contained flavonoids, alkaloids, tannins, and saponins, which might contribute to its analgesic properties. It was found that the higher the dose of extract administered, the greater the inhibition of pain that occurred, with a dose of 800 mg/kgBB showing optimal analgesic effectiveness, almost equivalent to paracetamol as a positive control. Statistical analysis showed significant differences between treatment groups, with doses of 200 mg/kgBB and 400 mg/kgBB showing lower effectiveness. This study recommends further exploration of the therapeutic benefits of red betel leaf extract and formulation development for wider medical applications.

Capsaicin-induced Ca2+ overload and ablation of TRPV1-expressing axonal terminals for comfortable tumor immunotherapy.

As a common malignancy symptom, cancer pain significantly affects patients' quality of life. Approximately 60%-90% of patients with advanced cancer experience debilitating pain. Therefore, a comprehensive treatment system that combines cancer pain suppression and tumor treatment could provide significant benefits for these patients. Here, we designed a manganese oxide (MnO2)/Bovine serum albumin (BSA)/polydopamine (PDA) composite nanoplatform internally loaded with capsaicin for cancer pain suppression and immunotherapy. MBD&C nanoparticles (NPs) can ablate tumor-innervated sensory nerve fibers via Transient receptor potential vanilloid 1 (TRPV1) channels, thereby reducing the pain caused by various inflammatory mediators. The ablation of TRPV1+ nerve terminals can also decrease the secretion of calcitonin gene-related peptide (CGRP) and substance P (SP) in sensory nerve fibers, thus reducing the tumor pain and inhibit tumor progression. MBD&C can promote calcium influx by activating overexpressed TRPV1 channels on the tumor membrane surface, thereby achieving cancer immunotherapy induced by endogenous Ca2+ overloading. In addition, MnO2 NPs can alleviate tumor hypoxia and mitigate the immunosuppressive tumor microenvironment (TME). Ultimately, this treatment system with dual capabilities of inhibiting tumor growth and relieving cancer pain makes comfortable tumor therapy feasible and paves the way for the development of patient-centered approaches to cancer treatment in the future.

Conditioned pain modulation: controlling for the order of baseline and conditioning.

Conditioned pain modulation (CPM) is assumed to capture endogenous pain modulation. In standard CPM designs, the evaluation of a painful test stimulus (TS) (baseline) is followed by a second evaluation of the TS during/after application of a painful conditioning stimulus (CS) (treatment). However, these standard CPM within designs (baseline always preceding treatment) do not control for order effects, which might help to distinguish specific CPM inhibition from general habituation. To tackle this issue, we conducted 2 separate studies where we controlled for order effects to investigate whether CPM effects depend on the order of baseline and treatment. In both studies, a sample of 60 participants underwent 2 CPM test blocks: one standard order block (baseline before treatment) and one reversed order block (treatment before baseline), separated by a 20-minute break (randomized order across participants). Pain thresholds and pain ratings of phasic heat stimuli served as measures of TS. Cold water (study 1) and cuff pressure algometry (study 2) served as CS. We found significant CPM order effects in both studies and for both measures of TS (pain threshold and ratings). Only the standard CPM order (baseline before treatment) yielded robust pain inhibition effects, whereas the reversed order (treatment before baseline) led to no modulation or seeming pain facilitation. Because control for order effects is otherwise mandatory in within designs, it is surprising that it has been neglected in standard CPM protocols. Finding pain inhibition only in the standard CPM order suggests that CPM inhibition is at least partially confounded with habituation.

High-Fatigue Dynamic Resistance Exercise Induces Significant Hypoalgesia Effect.

Hogge, R, Mascheri, M, Shurik, D, Hanney, WJ, and Anderson, AW. High-fatigue dynamic resistance exercise induces significant hypoalgesia effect. J Strength Cond Res 39(2): 165-172, 2025-Although dynamic resistance exercise is a recommended treatment for patients with musculoskeletal pain, optimal intensity to create hypoalgesia has not been established. Response to exercise may also be affected by biopsychosocial factors that modulate pain response. The first purpose was to compare the immediate effects of a high-fatigue/exertion leg extension, low-fatigue/exertion leg extension, and control condition on pressure pain threshold (PPT) applied to the quadriceps (local effects) and trapezius (systemic effects). The second purpose was to examine if psychological and pain sensitivity factors affected response to exercise. As a within-subject design, subjects completed psychological questionnaires, a control condition, and a 1-repetition maximum (1RM) during the first session. Subjects attended 2 more sessions where they completed 3 sets of a leg extension exercise at 50% of their 1RM until they reached a fatigue level of high fatigue (8/10 on the Borg CR-10) or low fatigue (3/10) with a randomized session order. A within-subject repeated-measures ANOVA was conducted (significance set at p < 0.05). High-fatigue exercise produced significantly higher PPT at the quadriceps than quiet rest after each set ( F [6,162] = 3.25, p < 0.01, partial eta 2 = 0.11). During low-fatigue exercise, individuals with an efficient endogenous pain inhibitory capacity displayed significantly higher PPT at the trapezius ( F [2.14, 55.61] = 3.31, p = 0.03, partial eta 2 = 0.11). Lower fear of pain was moderately associated with greater PPT increases at the trapezius ( r = -0.38, p = 0.04). Although high-fatigue exercise produces immediate local hypoalgesia, systemic hypoalgesia is affected by variability in pain inhibition and fear of pain.

Revealing the Progression of Pain Pathways and Identifying Chronification of Pain Predictors After an Isolated Lateral Ankle Sprain: Project RECOIL.

Persistent pain is a common complaint among civilians and military personnel after a lateral ankle sprain (LAS). Most individuals who experience pain after an LAS self-report a moderate pain intensity level that interferes with activity. This pain experience is mostly described through study designs and outcomes that limit the understanding of the acute to chronic pain transition after an LAS. The purpose of this prospective study is to quantify the prevalence rate of chronic ankle pain at 6-months post-injury and identify susceptibility and resiliency factors that contribute to pain chronification after an LAS. The objective of this study will be accomplished through a two-site prospective cohort study design with data collected at four timepoints (<7 days post-LAS, 3-, 6-, and 12-months post-LAS). A target sample size of 200 men or women (100 per site) between 18 and 45 years of age who sustain an acute LAS within the previous 7-days will be enrolled. Participants will complete a series of standardized electronic surveys at each timepoint to self-report the presence of chronic ankle pain, healthcare utilization patterns, subsequent musculoskeletal injury, and new co-morbid conditions. Additionally, participants will complete validated patient-reported outcomes (PROs) electronically to characterize the pain burden and undergo quantitative sensory testing to assess mechanical pain sensitivity via pressure pain thresholds, pain facilitation via temporal summation, and pain inhibition via a conditioned pain modulation response at all timepoints. Lastly, clinician-based outcomes will be completed at 3-, 6-, and 12-months post-LAS to examine dynamic postural control, functional performance, and walking mechanics. We hypothesize that 30% of participants will self-report chronic ankle pain at 6-months post-injury. In addition, chronic pain at 6-months will be predicted by a combination of healthcare utilization patterns, prolonged levels of peripheral sensitization and pain facilitation, and worse functional performance and PROs.

Pain is Modulated Differently Between Females With and Without Patellofemoral Pain: Factors Related to Sensitization.

Patellofemoral pain (PFP) has poor long-term recovery outcomes. Central sensitization describes central nervous system changes altering pain modulation, which can complicate recovery (poorer prognosis and worse function). Signs of central sensitization include amplified pain facilitation, pain hypersensitivity, and impaired pain inhibition, which can be measured with temporal summation of pain (TSP), pressure pain thresholds (PPTs), and conditioned pain modulation (CPM), respectively. Sex differences exist for these test responses, but female-only PFP investigations of sensitization are uncommon. Understanding pain modulation in females with PFP could improve treatment protocols. To determine whether females with PFP exhibit signs of central sensitization (greater TSP, lower PPTs, and reduced CPM) compared with pain-free females. Cross-sectional study. Laboratory. Thirty-three females ([20 PFP, 13 pain free]; age: PFP 29.2 ± 7 years, pain free 28 ± 7 years; height: PFP 166.7 ± 5.9 cm, pain free 166 ± 9.5 cm; mass: PFP 66.7 ± 9.6 kg, pain free 69.3 ± 7.5 kg). Temporal summation of pain was assessed with 10 punctate stimuli applied to the knee and calculated by the difference in pain intensity between beginning and end responses. Pressure pain thresholds were tested at 4 sites (3 for local hypersensitivity [knee] and 1 for widespread hypersensitivity [hand]). Conditioned pain modulation was conducted by comparing PPTs during 2 conditions (baseline and ice immersion). Conditioned pain modulation response was defined as the percent difference between conditions. Between-groups differences in TSP response were analyzed with a Welch test. Separate Welch tests analyzed group comparisons of PPTs and CPM responses at 4 sites. Females with PFP exhibited greater TSP response (P = .019) and lower CPM response at patella center (P = .010) and hand sites (P = .007) than pain-free females. Pressure pain thresholds group differences were not observed at any site (P > .0125). Females with PFP modulate pain differently than pain-free females. Clinicians should recognize signs of central sensitization and their potential effect on treatment options.

Management of Fibromyalgia: Novel Nutraceutical Therapies Beyond Traditional Pharmaceuticals.

The pathophysiology of fibromyalgia, a condition that causes chronic pain throughout the body, involves abnormal pain signaling, genetic predispositions, and abnormal neuroendocrine function, significantly impairing quality of life. Fibromyalgia is commonly characterized by musculoskeletal pain, chronic fatigue, and severe sleep alterations. Changes in the central processing of sensory input and defects in endogenous pain inhibition could be the basis of enhanced and persistent pain sensitivity in individuals with fibromyalgia. The term central sensitivity syndrome was chosen as an umbrella term for fibromyalgia and related illnesses, including myalgic encephalomyelitis/chronic fatigue syndrome, migraine, and irritable bowel syndrome. Given the substantial impact of fibromyalgia on health, there is a need for new prevention and treatment strategies, particularly those involving bioavailable nutraceuticals and/or phytochemicals. This approach is particularly important considering the adverse effects of current fibromyalgia pharmaceutical treatments, such as antidepressants and anticonvulsants, which can lead to physical dependence and tolerance. Natural products have recently been considered for the design of innovative analgesics and antinociceptive agents to manage fibromyalgia pain. Polyphenols show promise in the management of neuropathic pain and fibromyalgia, especially considering how anti-inflammatory treatments, including corticosteroids and nonsteroidal medical drugs, are effective only when inflammatory processes coexist and are not recommended as the primary treatment for fibromyalgia.

Adult Anaesthesia Practice at Zinder National Hospital

Introduction: Anesthesia allows surgery to proceed smoothly, with pain suppression, patient immobility and neurovegetative protection. The aim of this study is to describe anesthetic practice in adults at Zinder National Hospital. Patients and Method: it was a prospective cross-sectional study including patients aged at least 16 undergoing surgery at the Zinder national hospital from December 4, 2023 to March 3, 2024 (3 months). Results: During the study period, 560 anaesthetic procedures were performed in the operating theatre, of which 329 (58.8%) involved patients aged 16 or over. The mean age was 38.7±17.8, with extremes of 16 and 85 years. Past history was present in 30% of patients, dominated by hypertension. The types of surgery were: visceral surgery 48.9% followed by traumatology 27.1%, all patients were evaluated before anesthesia. General anesthesia (GA) was used in 61.4% of cases. In 55.3% of cases, patients were classified as ASA I. The drug regimen most commonly used for GA was: fentanyl, suxamethonium and ketamine in 38.4% of cases, and for spinal anesthesia, the bupivacaine-fentanyl combination. Anesthesia was provided by 2 anesthesiologists and 10 anesthesia technicians. More than half the patients developed adverse events in the operating room, and one (1) patient died (0.3%). Conclusion: This study provides us with information on the socio-demographic characteristics of patients, the types of surgery and the characteristics of adult anaesthesia at Zinder National Hospital. A number of aspects remain to be improved, including the number of anaesthetists and the availability of equipment such as respirators and capnographs.

Assessing the balance between excitation and inhibition in chronic pain through the aperiodic component of EEG

Chronic pain is a prevalent and debilitating condition whose neural mechanisms are incompletely understood. An imbalance of cerebral excitation and inhibition (E/I), particularly in the medial prefrontal cortex (mPFC), is believed to represent a crucial mechanism in the development and maintenance of chronic pain. Thus, identifying a non-invasive, scalable marker of E/I could provide valuable insights into the neural mechanisms of chronic pain and aid in developing clinically useful biomarkers. Recently, the aperiodic component of the electroencephalography (EEG) power spectrum has been proposed to represent a non-invasive proxy for E/I. We, therefore, assessed the aperiodic component in the mPFC of resting-state EEG recordings in 149 people with chronic pain and 115 healthy participants. We found robust evidence against differences in the aperiodic component in the mPFC between people with chronic pain and healthy participants, and no correlation between the aperiodic component and pain intensity. These findings were consistent across different subtypes of chronic pain and were similarly found in a whole-brain analysis. Their robustness was supported by preregistration and multiverse analyses across many different methodological choices. Together, our results suggest that the EEG aperiodic component does not differentiate between people with chronic pain and healthy individuals. These findings and the rigorous methodological approach can guide future studies investigating non-invasive, scalable markers of cerebral dysfunction in people with chronic pain and beyond.