Opioid Misuse by Adults with Chronic Pain: The Impact of Illness and Medication Beliefs.

BACKGROUND: Why do some adults with chronic pain misuse their prescription opioids when others do not? Based on the extended Common-Sense Model, the study evaluated whether adults' beliefs about their pain have an indirect effect on risk of opioid misuse through beliefs about opioids when controlling for depression. METHODS: The sample included 297 adult participants in the U.S. recruited from Prolific, an online crowdsourcing website. Study measures included the Illness Perception Questionnaire-Revised (IPQ-R; protective and threat-related illness beliefs about chronic pain), the Beliefs about Medicines Questionnaire-Specific subscale (BMQ-Specific; concern and necessity medication beliefs about prescription opioids), and the Current Opioid Misuse Measure (COMM; risk of current opioid misuse). This cross-sectional parallel mediation analysis was conducted using MPlus. RESULTS: After controlling for depression, the indirect effect of protective illness beliefs on opioid misuse risk through concern medication beliefs (b = -0.01, 95% CI (-0. 038, -0.001), and the indirect effect of threat-related illness beliefs on opioid misuse risk through necessity medication beliefs (b = 0.02, 95% CI (0.004, 0.036) were significant. The full model explained 35% of the variance of opioid misuse risk. CONCLUSIONS: Adults with chronic pain with stronger protective beliefs about pain were less likely to have concerns about their opioids and were at lower risk for opioid misuse, while those with greater threat-related beliefs about pain were more likely to believe that their opioids were necessary and be at greater risk for opioid misuse. Results have implications for medical and mental health providers and future research.

Hip and waist circumference correlations with demographic factors and pain intensity in patients with chronic pain.

Aim: This study aimed to investigate how demographic factors such as race, age, sex and ethnicity can impact hip circumference (HC) and waist circumference (WC) in patients with chronic pain.Materials & methods: We queried the NIH-sponsored All of Us database for patients with documented HC, WC and waist/hip ratio (WHR) data. This cross-sectional study categorized participants into four groups: total cohort, no chronic pain, mild/moderate chronic pain (numeric rating scale < 7) and severe chronic pain (numeric rating scale > 7). Further subgroup analyses were performed based on race, age, sex and ethnicity. We examined the correlation between chronic pain and WC, HC and WHR. ANCOVA analysis was used to determine to investigate demographics.Results: This study included 204,013 participants, with 25.22% having a chronic pain diagnoses. In most subgroups, females had significantly greater HC, while males had greater WC and WHR. WC (p < 0.001 in females, p < 0.01 in males), HC (p < 0.001 in females) and WHR (p < 0.001 in females, p < 0.05 in males) were significantly greater in the severe pain group compared with the mild/moderate pain group.Conclusion: These findings suggest that when assessing HC and WC, demographic variables need to be considered to develop more personalized and comprehensive treatment plans for chronic pain patients.

Our study looked at how factors like race, age, sex and ethnicity relate to hip and waist sizes in people with chronic pain. We wanted to see whether waist and hip measurements that lead to chronic pain is associated with race, age, sex and ethnicity. We used information from a database of patients with chronic pain formed in the USA. We grouped people based on how much pain they had (none, mild/moderate, severe) and then looked for differences between races, ages, sexes and ethnicities. Among men of all races, those with mild to moderate pain tended to have larger waists compared with those without pain. For women, those who experienced severe pain had larger waists and hips.We addressed how race, age, sex and ethnicity are associated with these results. Our main finding is that doctors should consider not just hip and waist sizes but also a patient's demographic background. This can help them create better treatment plans to determine risks of developing pain and individualizing treatment.

Transforming personalized chronic pain management with artificial intelligence: A commentary on the current landscape and future directions.

Artificial intelligence (AI) has the potential to revolutionize chronic pain management by guiding the development of effective treatment strategies that are tailored to individual patient needs. This potential comes from AI's ability to analyze large and heterogeneous datasets to identify hidden patterns. When applied to clinical datasets of a particular patient population, AI can be used to identify pain subtypes among patients, predict treatment responses, and guide the clinical decision-making process. However, integrating AI into the clinical practice requires overcoming challenges such as data quality, the complexity of human pain physiology, and validation against diverse patient populations. Targeted, collaborative efforts among clinicians, researchers, and AI specialists will be needed to maximize AI's capabilities and advance current management and treatment of chronic pain conditions.

The Combined Relationship of Prescription Drug Monitoring Program Enactment and Medical Cannabis Laws with Chronic Pain-Related Healthcare Visits.

BACKGROUND: U.S. state electronic prescription drug monitoring programs (PDMPs) are associated with reduced opioid dispensing among people with chronic pain and may impact use of other chronic pain treatments. In states with medical cannabis laws (MCLs), patients can use cannabis for chronic pain management, reducing their need for chronic-pain related treatment visits and moderating effects of PDMP laws. OBJECTIVE: Given high rates of chronic pain among Medicaid enrollees, we examined associations between PDMP enactment in the presence or absence of MCL on chronic pain-related outpatient and emergency department (ED) visits. DESIGN: We created annual cohorts of Medicaid enrollees with chronic pain diagnoses using national Medicaid claims data from 2002-2013 and 2016. Negative binomial hurdle models produced adjusted odds ratios (aOR) for the likelihood of any chronic pain-related outpatient or ED visit and incident rate ratios (IRR) for the rate of visits among patients with ≥ 1 visit. PARTICIPANTS: Medicaid enrollees aged 18-64 years with chronic pain (N = 4,878,462). MAIN MEASURES: A 3-level state-year variable with the following categories: 1) no PDMP, 2) PDMP enactment in the absence of MCL, or 3) PDMP enactment in the presence of MCL. Healthcare codes for chronic pain-related outpatient and ED visits each year. KEY RESULTS: The sample was primarily female (67.2%), non-Hispanic White (51.2%), and ages 40-55 years (37.2%). Compared to no-PDMP states, PDMP enactment in the absence of MCL was not associated with chronic pain-related outpatient visits but PDMP enactment in the presence of MCL was associated with lower odds of chronic pain-related outpatient visits (aOR = 0.81, 95% CI:0.71-0.92). PDMP enactment was not associated with ED visits, irrespective of MCL. CONCLUSIONS: During a period of PDMP and MCL expansion, our findings suggest treatment shifts for persons with chronic pain away from outpatient settings, potentially related to increased use of cannabis for chronic pain management.

Interdisciplinary pain program participants with high catastrophizing scores improve function utilizing enriched therapeutic encounters and integrative health techniques: a retrospective study.

Introduction: Pain catastrophizing describes helplessness, rumination, and magnification of a pain experience. High pain catastrophizing is an independent risk factor for disability, pain severity, inadequate treatment response, chronicity, and opioid misuse. Interdisciplinary pain programs (IPPs) are beneficial and cost-effective for individuals with chronic pain, but their functional impact on individuals with high pain catastrophizing is not well established. The emerging field of placebo studies suggests that patient-provider relationships, positive treatment expectations, and sociobiologically informed care trigger physiological responses that may enhance therapeutic interventions. Methods: In this retrospective observational cohort study, we compared admission and discharge data for 428 adults with high-impact chronic pain (mean 8.5 years) who completed the Spaulding-Medford Functional Restoration Program (FRP). The interdisciplinary FRP team of physiatrists, behavioral health clinicians, physical therapists, and occupational therapists specializes in evidenced-based conventional rehabilitation, integrative health, and pain psychoeducation via enriched therapeutic encounters, fostering collaboration, validation, trust, self-efficacy, and positive expectations. Clinical outcome measures included the Canadian Occupational Performance Measure (COPM) assessing functional performance (COPM-PS) and satisfaction with function (COPM-SS), the Pain Numeric Rating Scale (NRS), the Pain Catastrophizing Scale (PCS), and the Patient Health Questionnaire-9 (PHQ-9). Results: FRP participants with clinically elevated catastrophizing at baseline (PCS ≥30, mean PCS 39) achieved statistically significant improvements in function (mean delta -2.09, CHI2 = 15.56, p < 0.001), satisfaction with function (COPM-SS mean delta -2.50, CHI2 = 7.42, p = 0.007), pain (NRS mean delta 2.7), mood (PHQ-9 mean delta 1.87, p = 0.002), and catastrophizing (PCS mean delta 4.16, p < 0.001). Subgroup analysis revealed racial disparities in pain scores, and exploratory analysis showed a trend toward reducing opiate consumption. Discussion: Despite the known association of adverse outcomes with high catastrophizing, FRP participation was associated with increased productive engagement, reduced pain, reduced maladaptive thought processes, and improved mood. Although causation and efficacy cannot be established from a retrospective design, this is the first study to identify functional improvement in patients with high-impact chronic pain and clinically relevant high pain catastrophizing who participate in an IPP combining conventional and complementary rehabilitation with psychoeducation. These enriched therapeutic encounters may enhance the treatment process by promoting trust, empathy, collaboration, and beneficial reframing of patients' experiences, expectations, and goals.

A Review of the Application of Myofascial Release Therapy in the Treatment of Diseases.

Myofascial release (MFR) therapy is widely used in clinical practice to treat various musculoskeletal and pain-related conditions. However, there is a lack of comprehensive reviews that systematically evaluate its effectiveness across different medical conditions, leading to inconsistent applications and understanding of its therapeutic potential. This review aims to synthesize the current applications of myofascial release therapy in the treatment of various diseases, highlighting its efficacy and identifying areas where further research is needed. The review covers the application of myofascial release therapy in conditions such as chronic pain, fibromyalgia, post-surgical recovery, and neurological disorders. It evaluates the outcomes of existing studies, identifies gaps in the literature, and discusses the mechanisms through which myofascial release exerts its effects. Additionally, the review provides insights into the limitations of current research and suggests directions for future studies to enhance the clinical application of myofascial release therapy.

An in-Depth Exploration of Consumer and Consumer Representative Views on Chronic Pain Management in Australia: A Key Informant Interview Study.

Chronic pain affects millions of Australians. Despite guidelines recommending non-pharmacological approaches as the first line treatment, opioid medications remain among the most common treatments. This study interviewed consumers and consumer representatives (i.e., representatives of peak pain advocacy organizations in Australia) to gain first-hand perspectives on chronic pain treatment in Australia. Individual semi-structured Key Informant Interviews (KIIs) with three consumers and three representatives were undertaken. Interviews were transcribed, and thematic analysis applied. Results showed that consumers and consumer representatives identified critical treatment access barriers. Another shared theme related to overarching principles of care, with sub-themes pertaining to the need for an interdisciplinary approach and pain education. A further shared theme focused on typical medical interventions, with one shared subtheme regarding the benefits and drawbacks of pain medications. Both groups highlighted the importance of a biopsychosocial approach with consideration of mental health, particularly related to perceived stigma and comorbidities. These findings highlight that chronic pain remains both undertreated and inadequately treated in Australia. There is a critical need to use novel approaches to overcome access barriers and stigma, and to advance precision medicine to match patients to the treatment most likely to be of benefit as early as possible in their journey.

Older and Better: A Narrative Review of Successful Aging and Adaptation to Pain in Late Life.

"Invariably, the self-assessed QoL was far better than I, as a physician, would have anticipated from the diseases and disabilities that you reported." -Ben Eiseman, MD, based on a survey of his octogenarian Yale University classmates. BACKGROUND: Chronic pain control is a high priority for the elderly; it is one of the most frequently encountered medical problems in this group. Chronic pain affects 60%-75% of people aged 65 years and older. Chronic pain's prevalence is even higher in those living in assisted living or nursing homes. Based on epidemiological data, the prevalence of chronic pain is directly proportional to age and is especially so in women. At least one in 3 patients over age 65 report significant ongoing pain that is often inadequately treated. Despite this high prevalence of chronic pain in older persons, aging research sheds light on how this suffering may be reduced. Healthy aging is not an oxymoron. Successful aging and adaptation to chronic pain involve similar medical, temperamental, behavioral, and cultural factors. Older patients with chronic pain face well-documented cultural bias, fear, and clinical pessimism; but adaptive coping is a realistic expectation. OBJECTIVES: This narrative review aims to summarize the available literature on strategies used by older persons to optimize adaptation to late-life pain. STUDY DESIGN: This is a narrative review of a PubMed literature search 1947 to March 4, 2024. METHODS: A PubMed literature search covering years 1947 to March 4, 2024 was performed using permutations of the search terms pain, chronic pain, persistent pain, aging, elderly, and coping. Relevant articles were also obtained from careful review of the references in articles identified in the search. RESULTS: I summarized the available literature on strategies used by older persons to optimize adaptation to late-life pain. There are distinct differences between older persons and younger persons in the strategies they use to cope with chronic pain. Furthermore, I identified significant overlap between strategies and actions used by older persons to cope with pain and those strategies and actions used to successfully adapt to the aging process; these commonalities demonstrate a linkage of these adjustment processes and have clinical utility. Also presented are 2 cases that demonstrate the relevance of these factors for treating elderly patients with chronic pain. LIMITATIONS: The literature search was limited to PubMed, which excluded psychology databases. CONCLUSIONS: Chronic pain is common in the elderly and is not adequately treated. Data indicate that older persons can benefit from guidance toward distinct attitudes and actions they can employ to cope with persistent pain. Epidemiologic and aging literature describe attitudes and behaviors that facilitate health and wellbeing during aging. Data from gerontology and from research on chronic pain in elderly patients converge upon factors that are common to better adaptation to both aging and late-life pain. I describe these common factors, which I categorize as treatment-factors, traits, attitudes, and actions. Two cases are presented to demonstrate these concepts.

Yoga as an Adjunctive Treatment for Chronic Low Back Pain: A Narrative Review.

BACKGROUND: Yoga has been recognized for its many mental and physical health benefits. A growing body of literature supports yoga's indication in chronic low back pain (CLBP) management. CLBP is a major public health concern, given its high rates of associated disabilities and large healthcare costs. A biopsychosocial approach has been deemed the most effective and appropriate management strategy for this condition. When alternative and comprehensive approaches for managing the complexity of CLBP are considered, yoga poses a safe, accessible adjunctive treatment option. OBJECTIVES: The goal of this review is to demonstrate, by highlighting yoga's benefits on mental and physical health and the pathophysiology associated with CLBP, that yoga is an effective form of CLBP management. Our other goal is to establish that yoga encompasses a biopsychosocial approach to managing CLBP. STUDY DESIGN AND METHODS: After thorough examination of the available published literature, this narrative review evaluated 24 articles examining yoga's benefits to CLBP patients. RESULTS: CLBP is associated with high rates of anxiety, depression, chronic stress, and pain catastrophizing. Numerous studies support yoga as an effective intervention for depression, anxiety, chronic stress, and pain catastrophizing, given yoga's effects on the sympathetic nervous system, endocrine system, and various neurotransmitters and brain regions, and improvements in these areas may ameliorate the clinical symptoms experienced by CLBP patients. Physically, symptoms experienced by those with CLBP include pain, impaired function and mobility, disability, fatigue, and medication dependence, all of which, according to the literature, yoga has been shown to improve. Additionally, the chronicity and persistence of low back pain are related to central and peripheral sensitization, and yoga may intervene in these pathways to minimize symptom propagation. LIMITATIONS: This review is not without limitations. The current literature lacks standardization regarding which yoga poses are safe, appropriate, and effective for CLBP patients, which limits the generalizability of yoga therapy. Additionally, few existing prospective trials study yoga in the management of CLBP. Though numerous randomized controlled trials (RCTs) are included in this review, most of the current literature details other reviews or analyses of RCTs, includes smaller sample sizes, and lacks long-term follow-up data. Furthermore, many of these studies include patients who have volunteered or self-selected to trial yoga therapy for their back pain, indicating inherent selection bias. CONCLUSION: Overall, the current management strategies for CLBP do not encompass an effective biopsychosocial approach, and an intervention such as yoga is a promising adjunctive treatment for the condition.

Single Institutional Cross-Sectional Phone Survey Study: Evaluation of Causes for Loss to Follow-up After Spinal Cord Stimulator Implantation.

BACKGROUND: Spinal cord stimulation (SCS) is often an option of last resort for patients with post-laminectomy syndrome or an alternative option for patients with complex regional pain syndrome, chronic nonsurgical low back pain, or painful diabetic peripheral neuropathy when conservative management has failed. Although SCS is a helpful option, it is not without complications that can frequently lead to explantation of the SCS device and dissatisfaction with the treatment. Furthermore, as with any technology, SCS has potential issues that may lead to patient frustration and ultimately result in patient noncompliance and lack of follow-up visits. OBJECTIVES: The goals of this study are to explore the magnitude of and reasons for patient loss to follow-up after SCS device implantation. STUDY DESIGN: A cross-sectional phone survey. SETTING: A tertiary-care academic hospital. METHODS: A cross-sectional phone survey was performed on 49 patients who were deemed lost to follow-up when they did not return to the clinic one month after being implanted with permanent SCS devices at Beth Israel Deaconess Medical Center. Patients were administered an institutional review board-approved questionnaire exploring their reasons for not returning to the clinic. RESULTS: Over a 5-year period, 257 patients underwent full implantation of an SCS device. Of the 49 patients lost to follow-up, 24 were able to be contacted, and they completed the questionnaire. Twenty of the patients continued to use the SCS device but were lost to follow-up for the following reasons: 58% (14/24) due to improvement of pain, 13% (3/24) due to minimal improvement in pain control, 4% (1/24) due to other urgent health conditions, and 8% (2/24) due to patient noncompliance and missing follow-up appointments (4/24). Four patients discontinued using the SCS device after an average of 1.5 years +/- one year, 12% (3/24) due to inadequate pain control and 4% (1/24) due to inability to recharge the device (1/24). Of these patients, 2 of the 4 contacted their SCS representatives for help with troubleshooting prior to discontinuation. None of the patients was explanted. LIMITATIONS: The main limitation of this study was the incompletion rate, which was 51.0% (25 out of 49 patients). CONCLUSIONS: This paper, the first cross-sectional study of loss to follow-up among patients who are implanted with SCS devices, identifies that up to 19% of patients are quickly lost to follow-up after implantation. Only half of the patients in this study could be reached, with most successfully using their device for meaningful pain control, but a substantial number of patients likely required additional device optimization for pain relief.

Peripheral Nerve Stimulation Using High-frequency Electromagnetic Coupling (HF-EMC) Technology to Power an Implanted Neurostimulator With a Separate Receiver for Treating Peripheral Neuropathy.

BACKGROUND: Peripheral neuropathy is estimated to be prevalent in up to 12% of the population, increasing to 30% in older demographics. This makes peripheral neuropathy one of the most common neurological diseases in the United States. OBJECTIVES: This retrospective study aims to report on the efficacy and safety of peripheral nerve stimulation (PNS) on the treatment of peripheral neuropathy in a commercial setting. STUDY DESIGN: This was a retrospective study. A chart review was conducted for all eligible study patients. SETTING: This study was conducted at the Advanced Spine and Pain Center in San Antonio, a center focused on physical medicine and rehabilitation, pain management and advanced interventional procedures that effectively ease pain. METHODS: From September 2018 through July 2022, a total of 63 consecutive patients with peripheral neuropathy who presented with chronic pain symptoms originating from the shoulder, hip, knee, ankle, and groin were trialed in this study. All patients were required to be at least 18 years old. These patients underwent PNS therapy via implantation of the Freedom® PNS System (Curonix LLC) in order to treat their chronic pain related to or due to peripheral neuropathy from various peripheral nerve origins. RESULTS: The mean Numeric Rating Scale (NRS-11) score of 63 patients at baseline was 7.24 (SD, 1.80). At 2-3 weeks postimplantation, the mean NRS-11 score decreased to 3.43 (SD, 2.38). A total of 53 out of the 63 patients reported a reduction in their NRS-11 score at the 2-3 week follow-up. A total of 24 patients completed a long-term follow-up. The mean follow-up time was 763.13 days (SD, 428.42); all patients had their PNS system permanently implanted for at least 8 months (range, 255-1,592 days). LIMITATIONS: This was a retrospective study investigating the efficacy and safety of the Freedom® PNS System in patients with peripheral neuropathy. We were limited to the data available in the patient charts. CONCLUSION: PNS effectively treats chronic pain due to peripheral neuropathy for patients who have failed other conservative treatments.

Design of a Health Education Program to Manage Chronic Neck Pain: Protocol for a Development Study.

BACKGROUND: Chronic neck pain (CNP) needs attention to its physical, cognitive, and social dimensions. OBJECTIVE: We aimed to design a health education program (HEP) with a biopsychosocial approach for patients with CNP. METHODS: A literature search on CNP, health education, and biopsychosocial models was carried out. Seven physiotherapists with expertise in HEPs and chronic pain participated in three teams that evaluated the literature and prepared a synthesis document in relation to the three target topics. Experts compiled the information obtained and prepared a proposal for an HEP with a biopsychosocial approach aimed at patients with CNP. This proposal was tested in the physiotherapy units of primary care health centers belonging to the East Assistance Directorate of Madrid, and suggestions were included in the final program. RESULTS: The HEP for CNP with a biopsychosocial approach consists of 5 educational sessions lasting between 90 and 120 minutes, carried out every other day. Cognitive, emotional, and physical dimensions were addressed in all sessions, with particular attention to the psychosocial factors associated with people who have CNP. CONCLUSIONS: The proposed HEP with a biopsychosocial approach emphasizes emotional management, especially stress, without neglecting the importance of physical and recreational exercises for the individual's return to social activities. The objective of this program was to achieve a clinically relevant reduction in perceived pain intensity and functional disability as well as an improvement in quality of life in the short and medium term. TRIAL REGISTRATION: ClinicalTrials.gov NCT02703506; https://clinicaltrials.gov/study/NCT02703506. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/56632.

Open Surgical Implantation of Lumbosacral Dorsal Root Ganglion Stimulators for Chronic Pain: Analysis of Patient Outcomes and Operative Technique.

OBJECTIVE: Dorsal root ganglion (DRG) stimulator leads were designed to be placed percutaneously, yet open surgical placement via laminectomy is an option. We present the largest series to date of surgically-placed DRG stimulators and the first series where open surgical implantation was the chosen technique and not a salvage procedure. METHODS: A retrospective review of a prospective database of DRG implants identified 17 patients who had open lumbosacral DRG lead placement performed by a single surgeon (NDT) between October 2021 and April 2023. Descriptive statistics, fluoroscopy exposure times, and complications were reported. The window of data collection was 1 month pre-operatively to 12 months post-operatively. Phone interviews were conducted to collect information on pain outcomes and patient satisfaction. RESULTS: We identified 17 patients (12 women, 5 men) who had lumbosacral DRG placement. Phone interviews were conducted for 10/17 patients, with mean follow-up of 11.9 months. 53% reduction in mean pain score was achieved (n=10, p<0.001). There were no infections, hematomas, or symptomatic lead migrations. 1/17 experienced a superficial dehiscence and 2/17 had an intra-operative repairable durotomy with no post-operative sequelae. Mean fluoroscopy time per lead was 15.4±9.9s (n=10). CONCLUSION: Open DRG lead placement via laminotomy/laminectomy is reported as a salvage procedure but may have comparable safety and efficacy profile to percutaneous implantation when utilized as the primary implantation method. Before establishing open DRG as an alternative permanent implantation method, more studies are needed to determine whether such benefits as less migration outweigh the risks of a more invasive implantation procedure.

Sex differences in functional and structural alterations of hippocampus region in chronic pain: a DTI and resting-state fMRI study.

Introduction: It is well known that there are significant differences in the prevalence of chronic pain between males and females. Human and animal imaging studies have shown that chronic pain profoundly alters the structure and function of brain regions. However, there is limited research on the sex-specific mechanisms underlying the brain plasticity and adaptive changes associated with chronic pain. In this article, we conducted a multimodal study to evaluate how nerve injury-induced chronic pain affects the brain. Methods: Male and female Sprague-Dawley (SD) rats with spared nerve injury (SNI) model underwent resting-state functional magnetic resonance imaging (rs-fMRI) (male sham group: n = 18; male SNI group: n = 18; female sham group: n = 20; female SNI group: n = 18) and magnetic resonance diffusion tensor imaging (DTI) (male sham group: n = 23; male SNI group: n = 21; female sham group: n = 20; female SNI group: n = 21) scanning. ICA method, Fractional amplitude of low-frequency fluctuations (fALFF), immunofluorescence staining, and graph theory analysis was utilized to extract the rs-fMRI changes of brain regions of each group. Results: Using SNI model, which promotes long-lasting mechanical allodynia, we found that neuropathic pain deeply modified the intrinsic organization of the brain functional network in male and female rats (main effect of operation: F = 298.449, P < 0.001). 64 independent components (ICs) in the brain were divided and assigned to 16 systems. In male rats, we observed significant alterations in the microstructure of the hippocampal cornu ammonis 1 and cornu ammonis 2 (CA1/CA2) region, as indicated by increased mean diffusivity (MD) (CA1_L: P = 0.02; CA1_R: P = 0.031; CA2_L: P = 0.035; CA2_R: P = 0.015) and radial diffusivity (RD) (CA1_L: P = 0.028; CA1_R: P = 0.033; CA2_L: P = 0.037; CA2_R: P = 0.038) values, along with enhanced activating transcription factor 3 (ATF3) expression. Conversely, in female rats, we found significant increases in the fractional amplitude of low frequency fluctuations (fALFF) value within the hippocampal dentate gyrus (DG) (F = 5.419, P = 0.023), accompanied by elevated c-Fos signal (F = 6.269, P = 0.031). Furthermore, graph theory analysis revealed notable differences in the small-world network of the hippocampal system in female rats, characterized by reduced small-world attributes and increased inter-nodal transmission efficiency. Discussion: Our study indicates sex differences in structural and functional alterations in the hippocampal system in rats under chronic pain conditions. The results suggest that the hippocampus system plays an important role in the different mechanisms of chronic pain in different sexes. These findings provide reliable insights to explore the complex mechanisms underlying sex differences in chronic pain.

Changes of Trigeminal Ganglion Neurons Innervating the Temporomandibular Joint in Chronic Pain Rat Model.

Background: Phenotype alterations of nociceptive neurons have been shown to be a key step in the pathogenesis of many pain-related diseases. However, it is unclear if the characteristic changes of temporomandibular joint (TMJ) primary afferent neurons are related to the pathogenesis of temporomandibular joint osteoarthritis (TMJOA) chronic pain. This study aimed to determine the morphological and neurochemical changes in trigeminal ganglion (TG) neurons innervating the TMJ in TMJOA chronic pain rats. Materials and Methods: Monosodium iodoacetate (MIA)-induced TMJOA chronic pain rat model was established (n = 6), and saline was injected in rats of the control group (n = 6). TMJ primary afferent neurons were labeled with retrograde tracing (Dil). The spatial distribution and the expression of calcitonin gene-related peptide (CGRP), isolectin B4 (IB4), and neurofilament 200 (NF200) of TMJ primary afferent neurons in TG were investigated using immunofluorescence. Intracellular calcium signaling was recorded by calcium imaging (n = 20). Results: TMJ primary afferent neurons were located only in the V3 region of the TG from both saline- and MIA-injected rats. The number of TG neurons innervating the TMJ was increased in MIA-injected rats. Elevated number and intracellular calcium concentration of small- and medium-sized instead of large-sized Dil+ TG neurons were found in MIA-injected rats. The upregulated expression of CGRP and IB4, but not NF200, in TG neurons innervating the rat TMJs was accompanied by TMJOA chronic pain. Conclusion: This study suggests that sensitization of small- to medium-sized Dil+ TG neurons and CGRP- and IB4-positive Dil+ TG neurons might contribute to the development of TMJOA chronic pain in rats. This will provide valuable information for more efficient control of TMJOA chronic pain.

A surgical approach to complex regional pain syndrome with neurogenic thoracic outlet syndrome in a reoperation patient.

Thoracic outlet syndrome (TOS) and complex regional pain syndrome (CRPS) are two etiologies of chronic pain. TOS is a group of conditions that occur due to compression of the neurovascular structures of the upper extremity while CRPS is a disorder characterized by chronic and unremitting pain. This case highlights the experience of a 22-year-old female who presented following a traumatic injury to her left arm and was initially diagnosed with neurogenic TOS and later CRPS. Over a 10-year-period, she underwent a total of four operations to try and address her debilitating pain. In our third-time reoperation, symptoms of both pathologies nearly completely resolved with extensive neurolysis of the left brachial plexus and application of a scar tissue barrier.

A case report of a patient with severe & debilitating arm pain: Neurogenic thoracic outlet syndrome and complex regional pain syndrome are two disorders with the potential to cause severe and debilitating long-term pain, typically in an arm or leg. These two disorders are hard to diagnose, and patients can have variable responses to treatment. This case discussed a young woman who has severe pain of her left arm which eventually progress to the point that she had lost all meaningful use of the arm. After 8 years of treatments and four surgeries, she improved and began to regain her arm function.

Effect of neuromodulation for chronic pain on the autonomic nervous system: a systematic review.

Background: In recent years, there has been a growing interest in the use of neuromodulation as an alternative treatment option for chronic pain. Neuromodulation techniques, such as spinal cord stimulation (SCS), dorsal root ganglion (DRG) stimulation, deep brain stimulation (DBS), and peripheral nerve stimulation, have shown promising results in the management of various chronic pain conditions and involve targeted modulation of neural activity to alleviate pain and restore functional capacity. The autonomic nervous system (ANS) plays a crucial role in the regulation of various bodily functions including pain perception. However, the effects of neuromodulation on the ANS in the context of chronic pain remain poorly understood. This systematic review aimed to comprehensively assess the existing literature about the effects of neuromodulation on the ANS in chronic pain settings. Methods: Searches were conducted using four electronic databases (PubMed, EMBASE, SCOPUS, and Web of Science). The study protocol was registered before initiation of the review process. The Office of Health Assessment and Translation (OHAT) Risk of Bias tool was used to evaluate risk of bias. Results: A total of 43 studies were included, of which only one was an animal study. Several studies have reported more than one outcome parameter in the same population of chronic pain patients. Cardiovascular parameters were the most frequently used outcomes. More specifically, 18 outcome parameters were revealed to evaluate the function of the ANS, namely heart rate variability (n=17), arterial blood pressure (n=15), tissue oxygenation/perfusion (n=5), blood markers (n=6), multiunit postganglionic sympathetic nerve activity (n=4), skin temperature (n=3), skin conductance (n=3), cephalic autonomic symptoms (n=2), ventilatory frequency (n=2), vasomotor tone (n=1), baroreflex sensitivity (n=1), sympathetic innervation of the heart, neural activity of intrinsic cardiac neurons (n=1), vascular conductance (n=1), arterial diameter (n=1), blood pulse volume (n=1), and vagal efficiency (n=1). Most studies evaluated SCS (62.79%), followed by DBS (18.6%), peripheral nerve stimulation (9.3%), DRG stimulation (4.65%), and vagus nerve stimulation (4.65%). Overall, inconsistent results were revealed towards contribution of SCS, DBS, and peripheral nerve stimulation on ANS parameters. For DRG stimulation, included studies pointed towards a decrease in sympathetic activity. Conclusions: There are indications that neuromodulation alters the ANS, supported by high or moderate confidence in the body of evidence, however, heterogeneity in ANS outcome measures drives towards inconclusive results. Further research is warranted to elucidate the indirect or direct mechanisms of action on the ANS, with a potential benefit for optimisation of patient selection for these interventions. Systematic review protocol: PROSPERO (CRD42021297287).

Diurnal cortisol patterns in chronic pain: Associations with work-family spillover, work, and home stress.

Chronic pain is a prevalent condition with significant impacts on individuals' lives, including heightened stress and impaired physiological functioning. Given that work and family are the two main social domains where stress manifests, this study aimed to investigate the interactions between chronic pain, work-family stressors, and diurnal cortisol patterns to understand how chronic pain affects daily life and physiological stress responses. We identified 1,413 adults with chronic pain and 1,413 matched controls within MIDUS II samples to examine work-family spillover, daily work and home stressors, and cortisol levels across multiple days. The chronic pain group reported more negative work to family spillover and experienced more instances of stressful home events, particularly avoided arguments. These results align with literature suggesting chronic pain exacerbates tensions in close relationships and increases stress. The chronic pain group also had higher cortisol levels cross late-day periods, indicative of hypothalamic-pituitary-adrenal (HPA) axis dysregulation. This dysregulation is associated with poorer health outcomes, including increased inflammation and psychological distress. We did not find any differences in previously identified cortisol profiles, which are higher-level summaries of cortisol levels within each day. We discuss why such difference might not have appeared in this sample.

Correlating Evoked Electromyography and Anatomic Factors During Spinal Cord Stimulation Implantation With Short-Term Outcomes.

INTRODUCTION: We examine ways intraoperative neuromonitoring during spinal cord stimulation (SCS) varies between a high-resolution investigational SCS (HR-SCS) paddle and a commercial paddle. Furthermore, the presence of evoked motor responses (eg, electromyography [EMG]) in painful regions during surgery is correlated to outcomes. MATERIALS AND METHODS: We used HR-SCS to assess EMG response from 18 patients (NCT05459324). Maximum percentage change in root mean squared (maxRMS) EMG values was determined. Correlations were performed with magnetic resonance imaging measurements and patient outcomes collected preoperatively and at three months (numerical rating scale [NRS], McGill Pain, Beck Depression Inventory, Oswestry Disability Index [ODI], and Pain Catastrophizing Score). RESULTS: Of the 18 patients (12 women to six men; mean age 56 years; eight with neuropathic pain, eight with persistent spinal pain syndrome, two with complex regional pain syndrome), nine had a response at three months based on 50% reduction in NRS, 14 by achieving minimal clinically important difference (MCID) on NRS, and 11 by reaching MCID on ≥three outcome metrics. The anterior posterior diameter (APD) of the spinal column at level of testing correlated with all three responses (p < 0.05). We examined RMS at muscles correlating with individual patient pain distributions and found correlations between RMS and MCID NRS and MCID ODI (p < 0.05). maxRMS in abductor hallucis correlated with improvement in NRS and ODI across the group (p < 0.05). CONCLUSIONS: We found that eliciting EMGs over the painful areas during surgery caused alleviation of pain intensity and disability. Obtaining stimulation of abductor hallucis (AH) was more predictive of pain improvement than any other muscle group, and APD alone correlated with improvements in pain intensity and holistic outcomes. These pilot data suggest that implanters should consider APD and EMG responses from painful regions and AH during surgery.