Pain Conditions Research Articles

Prevalence and mechanisms of subacromial impingement in breast cancer patients after breast-conserving surgery and radiation therapy: a case-cohort study.

Subacromial impingement is a painful shoulder disorder, which may be common after breast cancer treatment. A previous study showed a high prevalence after mastectomy but prevalence after conservatively treated patients is unknown. Impingement mechanisms in breast cancer survivors have not been studied. Twenty-four breast cancer survivors who had undergone breast-conserving surgery without axillary lymph node dissection followed by radiation therapy, and 12 cancer-free controls were included. Breast cancer survivors were grouped by the presence of subacromial impingement pain. The subacromial space and the supraspinatus tendon were imaged using ultrasound on the treated side in the breast cancer survivors and a randomly chosen side in controls. In these images, the width of the subacromial space, thickness of the supraspinatus tendon and combined thickness of the supraspinatus tendon and surrounding soft tissues were measured. Subacromial impingement prevalence among breast cancer survivors was 54%. The width of the subacromial space and the thickness of the supraspinatus tendon were not different in breast cancer survivors with subacromial impingement compared to breast cancer survivors without subacromial impingement and controls. Combined thickness of the supraspinatus tendon and surrounding soft tissues was grater in breast cancer survivors with subacromial impingement. Prevalence of subacromial impingement is high, even in the most conservatively treated breast cancer patients. The presence of subacromial impingement pain is unrelated to width of the subacromial space, but greater thickness of the supraspinatus tendon and surrounding soft tissue may be part of the impingement mechanism.

A Missing Puzzle in Preclinical Studies—Are CCR2, CCR5, and Their Ligands’ Roles Similar in Obesity-Induced Hypersensitivity and Diabetic Neuropathy?—Evidence from Rodent Models and Clinical Studies

Research has shown that obesity is a low-grade inflammatory disease that is often associated with comorbidities, such as diabetes and chronic pain. Recent data have indicated that chemokines may play a role in these conditions due to their pronociceptive and chemotactic properties, which promote hypersensitivity and inflammation. Accumulating evidence suggests that CCR2, CCR5, and their ligands (CCL2, CCL3, CCL4, CCL5, CCL7, CCL8, CCL11 CCL12, and/or CCL13) play a role in rodent models of pain and obesity, as well as in patients with diabetes and obesity. It was proven that the blockade of CCR2 and CCR5, including the simultaneous blockade of both receptors by dual antagonists, effectively reduces hypersensitivity to thermal and mechanical stimuli in chronic pain states, including diabetic neuropathy. The present review discusses these chemokine receptors and the role of their ligands in diabetes and obesity, as well as their involvement in diabetic neuropathy and obesity-induced hypersensitivity.

Circulating Serum Micro-RNA as Non-Invasive Diagnostic Biomarkers of Endometriosis.

Endometriosis (END) is a painful gynecological condition. Clinical examination, imaging, and laparoscopy can provide a definitive diagnosis of END. Nonetheless, non-invasive biomarkers could help enhance and streamline the diagnostic process. Micro-RNAs (miRNAs), a family of small non-coding RNAs, could serve as useful non-invasive biomarkers for END. The aim of this study was to perform serum miRNA profiling in a retrospective cohort of women to identify miRNAs that are differentially expressed in END compared to control patients. RNA was isolated from serum samples of 67 END patients and 60 control women. The expression profile of a 754-miRNA panel was studied with RT-qPCR performed on a QuantStudio 12K Flex with the TaqMan OpenArray miRNA panel. A Censored Regression Model was used for miRNA differential expression analysis. Several gene-enrichment algorithms were employed to identify pathways related to the target genes of differentially expressed miRNAs. One hundred and thirty miRNAs were detected in at least 75% of samples from either the END or the control group. Sixteen miRNAs were significantly modulated between the END and control groups. Enrichment analysis identified targets significantly overrepresented in numerous pathways involved in biological processes related to END, including inflammation, angiogenesis, cellular invasion, cell-cycle/cell proliferation, and estrogen and progesterone hormonal signaling. Our study indicates that differentially expressed miRNAs between END patients and controls can be identified through liquid biopsy. Our findings also suggest a potential role for serum miRNAs in the pathophysiology of END, warranting further investigations for their use as non-invasive biomarkers.

Predicting “pain genes”: multi-modal data integration using probabilistic classifiers and interaction networks

Abstract Accurate identification of pain-related genes remains challenging due to the complex nature of pain pathophysiology and the subjective nature of pain reporting in humans, or inferring pain states in animals on the basis of behaviour. Here, we use a machine learning approach to identify possible “pain genes”. Labelling was based on a gold-standard list of genes with validated involvement across pain conditions, and was trained on a selection of -omics, protein-protein interaction network features, and biological function readouts for each gene. Multiple classifiers were trained, and the top-performing model was selected to predict a “pain score” per gene. The top ranked genes were validated against pain-related human SNPs to validate against human genetics studies. Functional analysis revealed JAK2/STAT3 signal, ErbB, and Rap1 signalling pathways as promising targets for further exploration, while network topological features contribute significantly to the identification of “pain” genes. As such, a network based on top-ranked genes was constructed to reveal previously uncharacterised pain-related genes including CHRFAM7A and UNC79. These analyses can be further explored using the linked open-source database at https://livedataoxford.shinyapps.io/drg-directory/, which is accompanied by a freely accessible code template and user guide for wider adoption across disciplines. Together, the novel insights into pain pathogenesis can indicate promising directions for future experimental research.

Prevalence and Clinical Correlates of Endometriosis in Patients With IC/BPS.

Interstitial cystitis/bladder pain syndrome (IC/BPS) presents as a complex heterogeneous disorder that poses a significant clinical challenge both for diagnosis and treatment. The identification of patient subgroups with significant overlap in their nonurological associated symptoms, including endometriosis, may enable a more targeted therapeutic approach. This study investigated the prevalence, clinical correlates, and clinical sequelae associated with concurrent endometriosis in patients with IC/BPS. Demographic, clinical, surgical, and questionnaire data from female patients (n = 533) with a diagnosis of IC/BPS were evaluated in this retrospective cohort study. Surgical history was obtained from patient electronic medical records, using Current Procedural Terminology (CPT) and International Classification of Diseases (ICD) codes. Data from participants with and without concurrent endometriosis were compared using univariate analysis, followed by binary logistic regression to identify associated variables. Of 533 participants, 108 (20.3%) reported a history of endometriosis. Those with concurrent endometriosis were younger, had a larger bladder capacity, and had a higher number of nonurological associated symptoms. Patients with concurrent endometriosis were less likely to have a history of cystectomy (the surgical removal of the bladder) and report allergies but more prone to report comorbidities such as chronic pelvic pain, chronic fatigue, fibromyalgia, migraines, and pelvic floor dysfunction. Binary logistic regression identified a positive association between endometriosis and chronic pelvic pain, and a negative association between allergies and low bladder capacity for those with concurrent endometriosis. Endometriosis is common in younger female patients with IC/BPS and is associated with a non-bladder-centric (ie, systemic pain disorder) phenotype.

Chronic Overlapping Pain Conditions in people with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): a sample from the Multi-site Clinical Assessment of ME/CFS (MCAM) study

BackgroundChronic overlapping pain conditions (COPCs), pain-related conditions that frequently occur together, may occur in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and could impact illness severity. This study aimed to identify comorbid COPCs in patients with ME/CFS and evaluate their impact on illness severity.MethodsWe used data from 923 participants in the Multi-Site Clinical Assessment of ME/CFS study, conducted in seven U.S. specialty clinics between 2012 and 2020, who completed the baseline assessment (595 ME/CFS and 328 healthy controls (HC)). COPCs included chronic low back pain (cLBP), chronic migraine/headache (cMHA), fibromyalgia (FM), interstitial cystitis/irritable bladder (IC/IB), irritable bowel syndrome (IBS), temporomandibular disorder (TMD). Illness severity was assessed through questionnaires measuring symptoms and functioning. Multivariate analysis of variance and analysis of covariance models were used for analyses. Log-binomial regression analyses were used to compute prevalence of COPCs and prevalence ratios (PR) between groups with 95% confidence intervals. Both unadjusted and adjusted results with age and sex are presented.Results76% of participants with ME/CFS had at least one COPCs compared to 17.4% of HC. Among ME/CFS participants, cMHA was most prevalent (48.1%), followed by FM (45.0%), cLBP (33.1%), and IBS (31.6%). All individual COPCs, except TMD, were significantly more frequent in females than males. The unadjusted PR (ME/CFS compared to HC) was highest for FM [147.74 (95% confidence interval (CI) = 20.83-1047.75], followed by cLBP [39.45 (12.73-122.27)], and IC/IB [13.78 (1.88-101.24)]. The significance and order did not change after age and sex adjustment. The COPC comorbidities of cLBP and FM each had a significant impact on most health measures, particularly in pain attributes (Cohen’s d effect size 0.8 or larger). While the impact of COPC comorbidities on non-pain attributes and quality of life measures was less pronounced than that on pain, statistically significant differences between ME/CFS participants with and without COPCs were still evident.ConclusionsMore than 75% of ME/CFS participants had one or more COPCs. Multiple COPCs further exacerbated illness severity, especially among females with ME/CFS. Assessment and management of COPCs may help improve the health and quality of life for patients with ME/CFS.

Development of a selective COX-2 inhibitor: from synthesis to enhanced efficacy via nano-formulation.

Non-steroidal anti-inflammatory drugs NSAIDs are widely used for managing various conditions including pain, inflammation, arthritis and many musculoskeletal disorders. NSAIDs exert their biological effects by inhibiting the cyclooxygenase (COX) enzyme, which has two main isoforms COX-1 and COX-2. The COX-2 isoform is believed to be directly related to inflammation. Based on structure-activity relationship (SAR) studies of known selective COX-2 inhibitors, our aim is to design and synthesize a novel series of 2-benzamido-N-(4-substituted phenyl)thiophene-3-carboxamide derivatives. These derivatives are intended to be selective COX-2 inhibitors through structural modification of diclofenac and celecoxib. The compound 2-benzamido-5-ethyl-N-(4-fluorophenyl)thiophene-3-carboxamide VIIa demonstrated selective COX-2 inhibition with an IC50 value of 0.29 μM and a selectivity index 67.24. This is compared to celecoxib, which has an IC50 value of 0.42 μM and a selectivity index 33.8. Molecular docking studies for compound VIIa displayed high binding affinity toward COX-2. Additionally, the suppression of protein denaturation with respect to albumin was performed as an indicative measure of the potential anti-inflammatory efficacy of the novel compounds. Compound VIIa showed potent anti-inflammatory activity with 93% inhibition and an IC50 value 0.54 μM. In comparison, celecoxib achieved 94% inhibition with an IC50 value 0.89 μM. Although molecule VIIa demonstrated significant in vitro anti-inflammatory activity, adhered to Lipinski's "five rules" (RO5) and exhibited promising drug-like properties, it showed indications of poor in vivo activity. This limitation is likely due to poor aqueous solubility, which impacts its bioavailability. This issue could be addressed by incorporating the drug in niosomal nanocarrier. Niosomes were prepared using the thin-film hydration technique. These niosomes exhibited a particle size of less than 200 nm, high entrapment efficiency, and an appropriate drug loading percentage. Transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) studies revealed that the niosomes were spherical and demonstrated compatibility of all of its components. The drug release study indicated that the pure drug had limited practicality for in vivo use. However, incorporating the drug into niosomes significantly improved its release profile, making it more suitable for practical use.

Surgical treatment of trigeminal pain

Surgical procedures for treating neuropathic pain, including trigeminal neuralgia (TGN), are categorized into three groups: decompression, ablation, and neuromodulation. Microvascular decompression is the only causal therapy for TGN, applicable favorably in cases of classical TGN due to avascular nerve conflict. Ablative procedures include both percutaneous and radiosurgical methods, which are mainly used for idiopathic trigeminal neuralgia. For irreversible neuropathies of the trigeminal nerve, the algorithm for other neuropathic pain conditions should be considered, along with the potential use of neuromodulatory techniques. When selecting a therapy, diagnosis, medication side effects, individual patient risks, and treatment outcomes must all be taken into account (current S1guideline from the German Society of Neurology).

Electrophysiological evidence of dry needling efficacy on spasticity in poststroke patients: A randomized control trial

Abstract: CONTEXT: Therapists use dry needling (DN) to treat myofascial trigger points and various pain conditions. Need for study: A gap analysis showed that more information about how DN works on spastic muscles through alpha motor neurofiring and what role it plays in clinical and functional outcomes. Currently, the objective evidence for the usefulness of DN in neurological diseases is required. AIMS: The purpose of this research was to examine how DN affects spasticity in stroke patients using the H reflex and a Modified Tardieu Scale (MTS). SETTINGS AND DESIGN: We conducted a randomized controlled trial. We randomly assigned 81 stroke survivors to one of two groups: one group underwent six sessions of DN over the muscles with conventional treatment, whereas the other group received conventional care. We assessed spasticity using the H reflex and the MTS. We analyzed all outcome measures before, after, and 2 weeks later names as H1, H2, H3 and T1, T2, and T2 receptivity. RESULTS: After the intervention, people who received DN had improvement in spasticity. H3-H1 is statistically significant (P = 0.42) in the experimental group against the control group. T3-T1 and T2-T3 are statistically significant (P = 0.00) in the experimental group compared to the control group. CONCLUSIONS: The DN is effective for lowering spastic muscle tone and local muscle stiffness. This could be because DN diminishes the nodular zone of spastic muscle and reduces the firing of alpha motor neurons. These findings are very promising in terms of lowering spasticity.

A Multimodal Approach to the Management of Diverticular Abscess with Paraesophageal Hernia Complication

This study aims to evaluate the management of acute diverticulitis complicated by hernia and the role of electroacupuncture in managing postoperative ileus. The case involved a 51-year-old male patient who presented with left lower abdominal pain, fever, and defecation disorder. Physical examination showed signs of infection with localized peritonitis, while laboratory tests revealed neutrophilia. CT scan showed diverticulitis with abscesses in the descending and sigmoid colon, as well as free air around the colon and perihepatic region, and paraesophageal hernia. The patient underwent left hemicolectomy with Hartmann's procedure. Postoperatively, the patient developed ileus which was treated using electroacupuncture. The results showed that the relationship between diverticulosis and hernia is due to connective tissue changes. Approximately 10-20% of diverticulosis cases progress to acute diverticulitis. CT scan is the gold standard for diagnosis, staging and management of diverticulitis. In cases of Hinchey III diverticulitis, laparoscopic washing does not give better results compared to colonic resection. The Hartmann procedure is recommended for patients with multiple comorbidities. Electroacupuncture proved to be an effective adjunctive therapy in managing postoperative ileus. The conclusion of this study is that a multimodal approach, including surgery and complementary therapies such as electroacupuncture, is essential in the management of diverticulitis and its complications. The implication of this study is the need for a holistic approach in managing patients with acute diverticulitis, especially in cases with multiple comorbidities and risk of postoperative complications.

Bedside Neuromodulation of Persistent Pain and Allodynia with Caloric Vestibular Stimulation.

Caloric vestibular stimulation (CVS) is a well-established neurological diagnostic technique that also induces many phenomenological modulations, including reductions in phantom limb pain (PLP), spinal cord injury pain (SCIP), and central post-stroke pain. We aimed to assess in a variety of persistent pain (PP) conditions (i) short-term pain modulation by CVS relative to a forehead ice pack cold-arousal control procedure and (ii) the duration and repeatability of CVS modulations. The tolerability of CVS was also assessed and has been reported separately. We conducted a convenience-based non-randomised single-blinded placebo-controlled study. Thirty-eight PP patients were assessed (PLP, n = 8; SCIP, n = 12; complex regional pain syndrome, CRPS, n = 14; non-specific PP, n = 4). Patients underwent 1-3 separate-day sessions of iced-water right-ear CVS. All but four also underwent the ice pack procedure. Analyses used patient-reported numerical rating scale pain intensity (NRS-PI) scores for pain and allodynia. Across all groups, NRS-PI for pain was significantly lower within 30 min post-CVS than post-ice pack (p < 0.01). Average reductions were 24.8% (CVS) and 6.4% (ice pack). CRPS appeared most responsive to CVS, while PLP and SCIP responses were less than expected from previous reports. The strongest CVS pain reductions lasted hours to over three weeks. CVS also induced substantial reductions in allodynia in three of nine allodynic CRPS patients, lasting 24 h to 1 month. As reported elsewhere, only one patient experienced emesis and CVS was widely rated by patients as a tolerable PP management intervention. Although these results require interpretative caution, CVS was found to modulate pain relative to an ice pack control. CVS also modulated allodynia in some cases. CVS should be examined for pain management efficacy using randomised controlled trials.

Percutaneous Electrical Stimulation Improves Chronic Knee Pain and Function. A Systematic Review and Meta-analyses.

The aim of this systematic review and meta-analysis was to evaluate the effectiveness of the percutaneous electrical stimulation in the modulation of pain and its implication in the function of patients with a painful knee condition. A search was conducted from database inception to September 2023 across PubMed, Web of Science and Scopus databases. Randomized controlled trials were included. Two reviewers performed independent data extraction and methodologic quality assessment of the studies. Study quality was assessed using the PEDro scale and the risk of bias was evaluated with the Cochrane Assessment tool. Eight studies were included. A significant statistical effect was found (P<0.001) for reducing pain and improving function after treatment. Additionally, a significant statistical effect was presented for reducing pain (P=0.009) and improving function (P<0.001) after follow-up. The risk of bias was low. This review showed a positive effect of applying the percutaneous electrical stimulation reducing pain and improving function in adults with a painful knee.

Unani Regimenal Therapy for Knee Osteoarthritis (Waja ‘al Rukba): A Comprehensive Scientific Assessment

Pain in the joints has been a common and serious health issue for a long time. In Unani medicine, both inflammatory and non-inflammatory joint problems are grouped under the term "Waja‘al-Mafāṣil," which means joint pain. Osteoarthritis, based on its symptoms, is very similar to a condition in Unani medicine called Waja‘al-Mafāṣil Balghamī. One of the most common types of osteoarthritis is Knee Osteoarthritis (KOA), which is known in Unani medicine as Waja‘al Rukba. This chronic and painful condition is usually treated with non-steroidal anti-inflammatory drugs (NSAIDs), but these drugs can have many side effects. In contrast, the Unani system of medicine uses a more comprehensive approach to manage osteoarthritis. Waja‘al Rukba is managed with Istefragh (evacuation) followed by Tadeel Mizaj (rejuvenation), Taqwiyat (strengthened) and Taskeen (pain is relieved). Istefragh is achieved using specific Unani herbal treatments, like Munzij-Mushil Therapy followed by Tadeel Mizaj using various techniques, including Ḥijāma (cupping), Dalk (massage), Ta‘līq al-‘Alaq (leech therapy), Ḥammām (Turkish Bath), Takmeed (fomentation), Naṭūl (irrigation), Qay‘ (vomiting), and Ḥuqna (enema). Taskeen and Taqwiyat are achieved using either medications or these modalities. This overview focuses on Waja‘al Rukba and its Regimenal management. Keywords Ilājbi’lTadbīr, Osteoarthritis, Unani, Waja ‘al Rukba, Waja‘al Mafāṣil,

Glial-modulating agents for the treatment of pain: a systematic review.

Preclinical research supports a critical role for nervous system glia in pain pathophysiology. This systematic review of human trials of potential glia-modulating drugs for the prevention or treatment of pain followed a predefined search strategy and protocol registration. We searched for English language, randomized, double-blind trials comparing putative glia-modulating drugs to placebo or other comparators. The primary outcomes included validated participant-reported measures of pain intensity or relief and, in studies of opioid administration, measures of opioid consumption and/or opioid-related adverse effects. Twenty-six trials (2132 participants) of glial modulators (12 minocycline, 11 pentoxifylline, and 3 ibudilast) were included. Because of clinical heterogeneity related to study drug, participant population, outcome measures, and trial design, no meta-analysis was possible. Only 6 trials reported a positive effect of the treatment (pentoxifylline-4 trials; minocycline-2 trials), whereas 11 trials reported mixed results and 9 trials reported no effect. This review does not provide convincing evidence of efficacy of current pharmacological targets of nervous system glial function for pain treatment or prevention. However, in light of ample preclinical evidence of the importance of neuroimmune signalling and glial functions in pain pathophysiology, continued strategic human research is anticipated to identify (1) drugs with maximal activity as selectively targeted glial modulators, (2) the necessary timing and duration of pharmacological glial modulation needed for pain prevention or treatment for specific injuries or pain conditions, and (3) the best design of future clinical trials of glial-targeted drugs for pain treatment and/or prevention.

Investigation of the effect of catechol-o-methyltransferase gene rs4680 polymorphism on trigeminal neuralgia susceptibility

Research has been conducted to explore the genetic basis of trigeminal neuralgia, a persistent pain condition that impacts the trigeminal nerve. COMT is an enzyme responsible for inactivating substances and hormones containing catechol and catecholamines. Previous research has linked COMT gene polymorphism with various pain conditions, including migraine. Our research aimed to investigate the correlation between trigeminal neuralgia and the rs4680 polymorphism of the COMT gene. We conducted a research project which included 10 individuals diagnosed with trigeminal neuralgia and 30 healthy individuals as controls. Following collection of blood samples, we isolated DNA from the samples and then genotyping of COMT rs4680 polymorphism was performed with Real-Time PCR, using TaqMan SNP Genotyping Assay. Among the trigeminal neuralgia patients, 2 of them exhibited the AA genotype, 6 had the AG genotype, and 2 had the GG genotype for COMT rs4680. The AG genotype was notably prevalent. No statistically significant differences in the distributions of COMT genotypes and allele frequencies were found between the experimental (patients) and the control group. However, the AG genotype appeared to be more frequent in the patient group. Moving forward, we plan to expand our study by increasing the number of patients and control subjects. This will enable us to further elucidate the potential relationship between COMT gene polymorphism and trigeminal neuralgia.

Metabotropic Glutamate Receptor 5: A Potential Target for Neuropathic Pain Treatment.

Neuropathic pain, a multifaceted and incapacitating disorder, impacts a significant number of individuals globally. Despite thorough investigation, the development of efficacious remedies for neuropathic pain continues to be a formidable task. Recent research has revealed the potential of metabotropic glutamate receptor 5 (mGlu5) as a target for managing neuropathic pain. mGlu5 is a receptor present in the central nervous system that has a vital function in regulating synaptic transmission and the excitability of neurons. This article seeks to investigate the importance of mGlu5 in neuropathic pain pathways, analyze the pharmacological approach of targeting mGlu5 for neuropathic pain treatment, and review the negative allosteric mGlu5 modulators used to target mGlu5. By comprehending the role of mGlu5 in neuropathic pain, we can discover innovative treatment approaches to ease the distress endured by persons afflicted with this incapacitating ailment.

Characteristics of men and women with medically diagnosed cluster headache in a national integrated healthcare system: A Veterans Health Administration cohort study.

Describe the epidemiology of cluster headache (CH) using Veterans Health Administration (VHA) Electronic Health Record (EHR) data. Epidemiologic studies of CH at the population level are difficult because it has a prevalence of ~0.1%. Hospital system-wide studies are an attractive alternative as they have large numbers of patients and broader populations than headache or neurology clinic-based studies. The VHA is an ideal hospital-based system in which to study CH because it is nationwide, predominantly male, has a strong focus on mood disorders and suicidality, and has accessible individual medical records. Here, we report the first headache study based on an ongoing longitudinal cohort of patients with CH using VHA EHR data. The VHA EHR data were accessed from Fiscal Year 2008 to 2019. Patients with CH consisted of all patients with at least one outpatient visit containing a CH diagnosis code from the International Classification of Diseases (ICD)-9 or -10. We extracted data on demographic features, incidence, and prevalence, as well as pain and psychiatric comorbidities. Of the 1,524,960 distinct patients who presented for headache treatment in the VHA between Fiscal Year 2008-2019, 24,131 had at least one visit with a CH diagnosis. The 1-year period prevalence of a CH diagnosis in the VHA ranges from 0.08% to 0.10% for women and 0.10% to 0.18% for men. A larger proportion of women versus men received a diagnosis of unspecified CH (59.6% [1412/2368] vs. 53.6% [11,663/21,763], p < 0.001). Most patients with CH had both comorbid headache and non-headache pain diagnoses. Headache not-otherwise-specified was the most common comorbid headache disorder at 70.0% (16,885/24,131) and was more common in women (76.1%, 1801/2368) compared to men (69.3%, 15,084/21,763). Other common comorbidities included migraine, depression, tobacco use, and obstructive sleep apnea. Rates of suicidal ideation or attempt were almost 50% higher in women (5-year proportion 9.4%, 222/2368) with CH compared to men (6.6%, 1433/21,763). To our knowledge this is the largest hospital system study of CH to date and reinforces several previous studies. Pain, mental health, and sleep disorders comorbidities are particularly prevalent in this group and were often more common in women compared to men with CH. Future work should examine gender and race stratified prevalence estimates within the VHA and other healthcare systems.

Predictors of Persistent Pain after Total Knee Arthroplasty

Background: Total knee arthroplasty (TKA) is an orthopedic procedure performed on patients with severe knee pain and advanced knee conditions, such as osteoarthritis and rheumatoid arthritis, in order to restore joint function. Despite the procedure’s high success rates, persistent postoperative pain (PPP) remains a significant complication, affecting a substantial proportion of patients. Identifying predictors of PPP is crucial for improving patient outcomes and satisfaction. Methods: A retrospective analytic study was conducted, reviewing the medical records of patients who underwent unilateral or bilateral TKA at King Abdulaziz Medical City. The data collection focused on demographics, comorbidities, clinical presentations, surgical details, and postoperative outcomes. Data were analyzed using JMP software. A p-value of less than 0.05 was considered statistically significant. Results: This study included 838 patients, predominantly female (71.5%), with an average age of 65.4 years. Osteoarthritis was the primary reason for surgery (98.3%). The mean preoperative pain score was 3.4, and the average pain duration prior to surgery was 6.2 years. We identified dyslipidemia as a significant predictor of PPP (OR 1.40, p = 0.042), while we found younger age to be a significant predictor (OR 0.979, 95% CI 0.967–0.991, p = 0.001). Other factors such as gender, diabetes, hypertension, cardiovascular disease, anxiety disorder, mood disorder, tobacco use, chronic kidney disease, chronic lung disease, and BMI were not significant predictors of PPP. Conclusion: This study identifies younger age and dyslipidemia as significant predictors of persistent postoperative pain and improved outcomes following total knee arthroplasty Further research is needed to validate these results in diverse populations and settings, with the objective should be to refine preoperative counseling and postoperative pain management protocols.

Characteristics of patients with somatoform pain disorder

AbstractBackgroundPatients with somatoform pain experience physical pain that cannot be attributed to any underlying medical or physiological cause, and it is often thought to be related to psychological factors. Health professionals encounter difficulties identifying this specific type of chronic pain, leading to suboptimal treatment strategies. Therefore, we aimed to describe the characteristics of patients with somatoform pain, to support the identification of affected patients.MethodsWe collected and analyzed a cross‐sectional survey data from 200 patients with somatoform pain admitted to one of three psychosomatic centers in Germany between August 2013 and July 2014. The survey contains 10 different categories, all of them referring to pain‐related topics. Within the survey, we analyzed validated as well as non‐validated questionnaires. Here, we present the following five: Personal data, Body: Pain perception, Cognition: Pain processing, Pain behavior, and Physical complaints.ResultsOur results highlight that most patients with somatoform pain experience it in several body parts and as persisting, lasting &gt;12 h/day (50%), and constantly changing (71%). Furthermore, patients indicate feelings of helplessness, by agreeing to the expressions the pain controls me (70%). Finally, we found that pain is predominantly seen as suffering, failing to convey emotional pain, despite cognitively acknowledging the dependency of emotional and physical pain.ConclusionThe study identified specific and distinctive characteristics in the emotional and behavioral responses of patients with somatoform pain, potentially distinguishing them from other patients with chronic pain.

Suppression of Visceral Nociception by Selective C-Fiber Transmission Block Using Temporal Interference Sinusoidal Stimulation.

Chronic visceral pain management remains challenging due to limitations in selective targeting of C-fiber nociceptors. This study investigates temporal interference stimulation (TIS) on dorsal root ganglia (DRG) as a novel approach for selective C-fiber transmission block. We employed (1) GCaMP6 recordings in mouse whole DRG using a flexible, transparent microelectrode array for visualizing L6 DRG neuron activation, (2) ex vivo single-fiber recordings to assess sinusoidal stimulation effects on peripheral nerve axons, (3) in vivo behavioral assessment measuring visceromotor responses (VMR) to colorectal distension in mice, including a TNBS-induced visceral hypersensitivity model, and (4) immunohistological analysis to evaluate immediate immune responses in DRG following TIS. We demonstrated that TIS (2000 Hz and 2020 Hz carrier frequencies) enabled tunable activation of L6 DRG neurons, with the focal region adjustable by altering stimulation amplitude ratios. Low-frequency (20-50 Hz) sinusoidal stimulation effectively blocked C-fiber and Aδ-fiber transmission while sparing fast-conducting A-fibers, with 20 Hz showing highest efficacy. TIS of L6 DRG reversibly suppressed VMR to colorectal distension in both control and TNBS-induced visceral hypersensitive mice. The blocking effect was fine-tunable by adjusting interfering stimulus signal amplitude ratios. No apparent immediate immune responses were observed in DRG following hours-long TIS. In conclusion, TIS on lumbosacral DRG demonstrates promise as a selective, tunable approach for managing chronic visceral pain by effectively blocking C-fiber transmission. This technique addresses limitations of current neuromodulation methods and offers potential for more targeted relief in chronic visceral pain conditions.