Frontiers in pain research (Lausanne, Switzerland)最新文献

Individuals who have visual impairments (IVI) face unique challenges in coping with and adjusting to chronic pain. However, this population remains underrepresented in chronic pain research and often encounters barriers in accessing effective, tailored healthcare. The primary objective of this study is to generate baseline data on the prevalence, types, and impact of chronic pain in this population. The secondary objectives are to identify specific challenges in pain management and provide evidence to identify specific challenges in pain management and to provide evidence that can inform the development of targeted interventions aimed at promoting equitable healthcare and improving quality of life. An international cross-sectional observational study will be conducted using an online survey administered via LimeSurvey. The survey, developed specifically for this project, will be accessible in multiple languages to enhance participation and representativeness. It is designed to capture the unique aspects of chronic pain, ocular and non-ocular forms, in IVI, including barriers to care and management challenges. This protocol aims to establish a comprehensive understanding of chronic pain in IVI. The findings will help bridge current research gaps, guide tailored interventions, and inform policy initiatives, ultimately reducing healthcare disparities and enhancing quality of life for this underserved group.

Background: Fibromyalgia syndrome (FMS) is linked to central sensitization and neuroplastic alterations that contribute to chronic pain, fatigue, cognitive, sleep, and affective disturbances. Conventional treatments offer limited benefit. Non-invasive transcranial electrical stimulation (tES), particularly transcranial direct current stimulation (tDCS), may modulate brain function and relieve symptoms, but findings remain inconsistent.

Objective: To systematically review and meta-analyze the effects of tES on clinical, neurophysiological, neuropsychological, and neurochemical outcomes in FMS.

Methods: Seven databases were searched for studies published between April 2013 and April 2023. Eligible designs included randomized controlled trials, cross-over, one-arm, and case studies involving adult FMS patients. Data extraction followed Cochrane Collaboration guidelines and used RevMan 6.6.0.

Results: Anodal tDCS produced short- to mid-term reductions in pain and mood symptoms, especially when applied over M1 or DLPFC. Longer interventions and repeated sessions enhanced effects, though protocol heterogeneity limited comparability. Both subjective (VAS, NRS) and objective (QST) measures confirmed pain reduction. Cognitive improvements were inconsistent, and quality of life effects were limited. Neurophysiological and neurochemical changes suggested possible mechanisms, though findings varied. Study quality was mixed, with small sample sizes and methodological inconsistencies. Meta-analysis revealed statistically significant but small effects on pain (Hedges' g < 0.2), with limited evidence on clinical relevance.

Conclusions: Anodal tDCS may offer short-term relief of pain and mood symptoms in FMS, potentially through modulation of cortical excitability and neuroplasticity. However, due to variability in findings and methodological limitations, its clinical relevance remains unclear. Future trials should use standardized protocols, assess long-term effects, and include clinically meaningful outcome measures.

Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD42023412332, PROSPERO CRD42023412332.

Chronic pain is one of the leading causes of disability worldwide. It can result in a significant reduction in quality of life and has been associated with decreased neurocognitive performance in attention, memory, and processing speed. Spinal cord stimulation (SCS) is a surgical treatment option for drug-refractory chronic pain. Although SCS can improve pain perception and related physical well-being, the mechanisms by which SCS improves pain perception and affects cognition remain largely unknown. Here, we review the cognitive impairments and neuroanatomical changes that can arise from chronic pain and how SCS treatment impacts these. This review identifies four key regions that may modulate attention, executive and emotional functioning, and memory with SCS: the amygdala, anterior cingulate cortex, thalamus, and somatosensory cortex. These observations suggest a role for SCS to influence and modulate the cognitive-emotional aspects of pain perception. Our review provides new insights to identify potential cortical areas that can serve as biomarkers or neuromodulation targets for SCS treatment. Recognizing the changes in activity within these supraspinal regions during SCS treatment may help individualize pain treatment and induce favorable cognitive shifts.

Introduction: Reduced pain perception following a persistent noxious stimulus during a study session (short-term habituation) is believed to be partially mediated by descending inhibitory mechanisms, although these mechanisms have not been fully elucidated. We examined the hypothesis that cardiopulmonary baroreceptor would significantly increase short-term habituation in chronic back pain (CBP) patients.

Methods: A short-term habituation protocol was utilized that involved 1-sec pulses (×10) at 105% heat pain threshold on the anterior forearm at 0.5 Hz. Cardiopulmonary baroreceptor unloading was performed via lower body negative pressure (LBNP) that reduces central venous pressure to elicit a reflex increase in sympathetic nerve activity.

Results: Short-term habituation was observed in young, healthy participants (n = 11), as indicated by a reduction in subjective pain ratings across the 10 repetitive heat pulses (-42% ± 29, P < 0.01, n = 11). Short-term habituation was also observed in CBP patients (-32% ± 30, P < 0.01, n = 12). Cardiopulmonary baroreceptor unloading via LBNP significantly reduced pain ratings across the 10 repetitive heat pulses in CBP patients compared with supine control (patient positioned in LBNP chamber but without a reduction in pressure) and upright sitting (chair), as indicated by a more negative area under the curve index (LBNP: -16.3 ± 4.1; Control: -14.4 ± 2.6; Upright sitting: -15.1 ± 4.1, P = 0.02). However, LBNP-mediated reductions in pain ratings were selective to CBP patients with more severe symptoms, i.e., neuropathic pain (LBNP: -14.7 ± 2.1; Control: -12.8 ± 1.4; Upright sitting: -12.1 ± 1.2, P = 0.04), whereas no effect of LBNP was observed in young, healthy participants (P = 0.83). In support, CBP patients with neuropathic pain exhibited significantly elevated mechanical pressure pain threshold during LBNP (P = 0.04).

Conclusions: Together, these findings demonstrate an association between cardiopulmonary baroreceptor unloading and a reduction in pain perception during repetitive noxious stimuli in CBP patients, particularly among CBP patients with greater pain severity.

Introduction: Menstrual-related pain and sleep disturbances are widespread in women experiencing premenstrual syndrome and primary dysmenorrhea. Such disturbances could be alleviated through repeated whole-body cryostimulation (WBC) sessions. Therefore, this study aimed to assess the effect of menstrual-related pain on sleep parameters, and the impact of WBC exposures on pain and sleep.

Materials and methods: Pain and sleep were evaluated for two 5-day periods under different conditions (control vs. WBC), randomly assigned across two consecutive menstrual cycles. Measurements began when the first pain/symptom indicating the onset of the menstrual phase was experienced. Pain was rated using a scale, while sleep was assessed using accelerometers and questionnaires. Throughout the 5-day WBC exposure, women underwent 3-min exposure to intense ventilated cold air each evening. After data collection, participants were categorized into high (HP) or low/no pain (LP) groups based on control pain scores.

Results: Twenty-nine naturally menstruating women were assessed. Perceived sleep quality was lower in the HP group compared to the LP group during the control condition (Spiegel score: 20.1 ± 2.3 vs. 22.3 ± 1.9, respectively; Cohen's d = 1.1). Across both groups, perceived sleep quality improved with the number of WBC exposures (night1: 19.5 ± 3.2 vs. night5: 23.5 ± 3.8; Hedge's g = 1.10). In the HP group, pain was reduced in the WBC condition compared to the control condition. Changes in pain and perceived sleep quality following WBC were correlated (r = -0.86).

Discussion: Women experiencing higher menstrual-related pain reported poorer perceived sleep quality. Their pain was reduced by WBC exposures. This improvement was highly associated with the enhancement in sleep quality.

Postherpetic neuralgia (PHN) is a debilitating chronic pain condition that significantly affects the quality of life, often leading to physical discomfort, emotional distress, and psychological comorbidities, such as depression and anxiety. This study aimed to systematically assess the neural oscillatory activity and functional connectivity patterns in patients with PHN using resting-state electroencephalography (EEG). Overall, 21 patients with PHN and 17 healthy controls participated in this study. Resting-state EEG data were collected and analyzed. Power spectrum density analysis was conducted to compare frequency band activity, and correlation analyses were used to examine associations between EEG power and psychological symptoms. Functional connectivity was assessed using the weighted phase lag index. Power spectrum density analysis revealed significantly higher EEG power across the delta, theta, alpha, beta, and gamma frequency bands in patients with PHN compared with controls. Correlation analyses indicated that delta and theta frequency band power were positively associated with the Beck Depression Inventory scores, whereas delta frequency band power was negatively correlated with the State Anxiety Inventory scores. Additionally, functional connectivity analysis demonstrated reduced gamma-band connectivity in patients with PHN, particularly in regions of the sensorimotor and pain modulation networks. These findings suggest that PHN is characterized by widespread hyperactivity in neural circuits, accompanied by disrupted interregional communication. These results provide valuable insights into the neurophysiological mechanisms underlying PHN and highlight potential biomarkers for developing targeted neuromodulatory treatments to alleviate pain and improve the psychological well-being of affected individuals.

Background: The best treatment yielding clinical benefits was still equivocal and controversial for the treatment of cervical radicular pain (CRP). This study aimed to propose a novel combination strategy of percutaneous cervical nucleoplasty (PCN) and ultrasound-guided pulsed radiofrequency (PRF) of cervical nerve root for CRP, and to compare its therapeutic effects with PRF alone.

Methods: 120 CRP patients who satisfied the inclusion requirements between January 2016 and March 2019 were retrospectively analyzed and split into PCN + PRF and PRF groups. The propensity score matching (PSM) technique was used to correct the imbalanced confounding variables between the groups. Then, clinical outcomes including the visual analog scale (VAS) score, Neck Disability Index (NDI) score, clinical assessment scale for cervical spondylosis (CASCS), modified MacNab criteria, radiological parameters, and complications were evaluated.

Results: In all, 120 patients were used to calculate the propensity score, producing 26 matched pairs that were monitored for a minimum of a year. When compared to the preoperative data, both groups' neck pain VAS scores, arm pain VAS scores, NDI scores, and CASCS scores saw a significant improvement during the follow-up period (p < 0.001). However, patients in the PRF group noted higher neck pain VAS scores, arm pain VAS scores, NDI scores, and CASCS scores than those in the PRF + PCN group at the final follow-up (p < 0.05). The decrease in surgical level disc height was more pronounced in the PRF + PCN group at the final follow-up (P < 0.05). The ROM was reduced in the PRF group but increased in the PRF + PCN group at the final follow-up (P < 0.01). Based on the modified MacNab criteria, the PRF and PCN + PRF groups had excellent and good rates of 76.92% and 84.62%, respectively, with no statistically significant difference (P > 0.05).

Conclusion: We present and describe a novel strategy for the combined treatment of CRP in chronic cervical radicular pain using ultrasound-guided percutaneous disc radiofrequency ablation PCN and spinal nerve root pulse radiofrequency PRF, which is both effective and safe throughout the treatment process, reducing pain and improving function.

Background: Chronic pain affects a significant portion of the population, and conventional treatments often prove insufficient. Spinal Cord Stimulation (SCS), a neuromodulation technique, has shown benefits in pain relief, while physiotherapy is widely employed to enhance physical function and quality of life. Although the combination of these approaches may offer synergistic effects, existing evidence is limited and fragmented.

Objective: This systematic review aimed to evaluate the clinical outcomes of Spinal Cord Stimulation (SCS), with or without the association of physiotherapy, in the management of chronic pain in adults. Methodology: The review was conducted following PRISMA guidelines and the PICO strategy. A comprehensive search was performed across databases including Cochrane Library, ScienceDirect, BASE, and VHL (BVS: MEDLINE, IBECS, WPRIM, LILACS, PERIÓDICO CAPES) using MeSH terms and Boolean operators: ("Spinal Cord Stimulation" OR "Neuromodulation") AND ("Chronic Pain" OR "Pain Management") AND ("Physical Therapy Modalities" OR "Physiotherapy" OR "Rehabilitation"). Only studies published in English, Spanish, or Portuguese in the past 10 years were included, focusing on chronic pain and reporting outcomes related to pain reduction and functional improvement.

Results: Eight studies comprising 777 patients were included. Spinal cord stimulation alone led to significant pain reductions, with responder rates above 80% and average decreases of 5-6 cm on pain scales. Improvements in quality of life and functional disability were also reported, with reductions of over 30 points in disability indices and up to 40% in opioid use. However, only one study included physiotherapy as a complementary intervention, without isolating its effects. No study directly evaluated the combined efficacy of SCS and physiotherapy, highlighting a gap in the literature.

Conclusion: The findings highlight the proven effectiveness of SCS in chronic pain management but reveal a lack of studies assessing its integration with physiotherapy. Future clinical trials should address this gap to explore potential synergistic effects and optimize interdisciplinary pain treatment strategies.

Background: Low back pain (LBP) is the most common reason for outpatient opioid prescribing: a quarter of patients receive prescriptions, leading to opioid use disorder (OUD) in 5%. Guideline-recommended multimodal interventions often face implementation barriers, and effective modalities (e.g., electrical stimulation) lack coverage. A multimodal mechanical stimulation (M-Stim) device for LBP has demonstrated safety and efficacy in pain reduction, but its impact on opioid use has not yet been determined.

Methods: As part of an NIH-funded double-blind study to reduce pain and opioid use, patients with moderate-to-severe LBP presenting to two suburban chiropractic centers were randomized to receive either the M-Stim device or a transcutaneous electrical nerve stimulation (TENS) unit for 30 min daily, in addition to other therapies. Analgesic use was reported daily for 28 days, with new prescribing followed weekly for 3 months. The primary outcome was prescribing in the opioid-naïve subjects. Secondary endpoints included risk factors for prolonged use in the opioid-naïve subjects, milligram morphine equivalents (MME) for opioid users between the first and last 2 weeks, and prescribing compared with national rates.

Results: After informed consent, 159 eligible patients were randomized to M-Stim (87) or TENS (72) (mean age 42.6 years, 54% female, BMI 30.9, NRS 5.5) between 23 June 2022 and 31 December 2023. Zero opioid-naïve M-Stim participants (n = 43) received prescriptions (0% vs. 8.6%, Fisher's exact p = 0.086), and those taking opioids used significantly fewer MME [7.5 (SD 3.54) vs. 498.5 MME (SD 474.9), p < 0.0001] for fewer of reported days [M-Stim 2/47 (4.2%)] compared with TENS [n = 36, 38/102 (37%), RR 0.11 (95% CI 0.28-0.44), p = 0.0018]. M-Stim significantly reduced MME in opioid users [-44.6% (32.33 MME), p = 0.02], use days for those with BMI ≥30 [-3 (99% CI -5.73 to -0.26), p = 0.032], and prescribing compared with national rates [9.8% vs. 25%, -63%, RR 0.32 (95% CI 0.16-0.66), p = 0.002] while TENS did not.

Conclusions: Among chiropractic patients with moderate-to-severe LBP, added use of a multimodal M-Stim device in the opioid-naïve subjects significantly reduced factors associated with OUD compared with TENS and reduced use days for those with BMI ≥30. This novel device is a potential alternative to prescribing opioids as first line for LBP management.

Clinical trial registration: https://clinicaltrials.gov/study/NCT04491175, identifier NCT04491175.