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

Chronic musculoskeletal (MSK) pain can be characterized by its temporal variability and evolution, affecting both pain management and treatment outcomes. While pain variability is traditionally studied over long timescales (e.g. days or weeks), few studies have explored short-term fluctuations (e.g. minutes to seconds) and their clinical relevance. This study investigated the short-term variability of chronic musculoskeletal pain across consecutive days, examining whether these fluctuations are stable, exhibit consistent temporal patterns, and relate to clinical severity. We also explored whether individuals with chronic MSK pain could predict their pain intensity on the following day, suggesting an ability to learn about their pain's levels. Eighty-one participants with chronic MSK pain to the back, neck, leg or arm (22-65 years, 72% females, 28% males) rated their pain continuously over two days, using a smartphone-based app. Results indicated that pain ratings were stable and exhibited consistent temporal patterns across days, with a temporally correlated structure. High mean pain levels were associated with lower variability, possibly reflecting a stabilized pain state. Short-term pain variability negatively correlated with clinical severity, indicating that greater variability is linked to milder pain. These findings highlight the importance of short-term variability as a distinct and clinically relevant feature of chronic MSK pain, with implications for personalized pain management strategies.

Quantitative pain assessment is important for effective pain management. Pain pressure threshold (PPT) and Pain Tolerance (PT) measured through pressure algometry offer valuable tools for quantitative evaluation of nociceptive stimuli. Low-cost algometers, described in literature require complex calibration and lack a digital interface, limiting real-time data acquisition and integration with electronic health record systems. In the current study, we developed a durable and accurate pressure algometer built on the base of a syringe, an Arduino microcontroller and an analog piezoelectric pressure sensor. The PPT values obtained with our device are in good correlation with data obtained utilizing commercially available digital and mechanical algometers. In addition, our device can be easily connected to a computer via a USB, allowing for convenient data storage and analysis. Our results demonstrate the accuracy and reliability of a novel algometry device constructed from readily available materials and requires minimal engineering and programming skills.

Medically refractory, severe, and unrelenting neuropathic pain remains a public health challenge worldwide. Green light has been found to have an analgesic effect on neuropathic pain. Interestingly, this analgesic effect is prolonged even after green light exposure. Peripheral and central mechanisms include the inhibition of the inflammatory response and the activation of the endogenous cannabinoid system and nerve circuits between the lateral geniculate nucleus and other brain regions, such as the dorsal raphe nucleus and the rostral ventromedial medulla, which may mediate the analgesic effect of green light. An increasing number of clinical studies highlight the side effects of traditional analgesics. The antinociceptive effect of green light has been proven in fibromyalgia and migraine patients. However, the effect of green light on neuropathic pain has not been reported in clinical settings. Here, we review the cellular and molecular mechanisms of the antinociceptive effect of green light. Furthermore, the green light parameters (intensity, duration, and wavelength) used in clinical trials are also summarized.

Background: Trigeminal neuralgia (TN) causes severe facial pain and affects quality of life. Radiofrequency rhizotomy (RFR) is often used when medications fail. This multicenter study assesses pain relief and patient satisfaction following this minimally invasive procedure in affected individuals treated across multiple institutions in Saudi Arabia and Pakistan.

Methods: In this prospective cohort study, 50 patients aged 40-60 with medically refractory TN (V2/V3) underwent percutaneous RFR at 75°C for 60 s under fluoroscopy, followed by dexamethasone injection. Pain (VAS) and patient satisfaction (PGIC) were evaluated at 1 and 6 months post-procedure. Inter-statistical analysis of patients' clinical outcomes using repeated measures ANOVA and Chi-square tests was performed.

Results: The average age of the participants was 50.58 ± 5.67 years. 72% were female. The right side was more commonly affected (62%) than the left (38%). The maxillary branch (V2) was the most frequently involved (76%), followed by the mandibular branch (V3) in 24%. Pain scores significantly decreased from a baseline mean of 8.04 ± 0.78-3.20 ±  1.05 at 1 month and 2.58 ± 1.18 at 6 months (p  <  0.001). Patient satisfaction scores also improved significantly, from 5.60 ± 1.20 at baseline to 2.52 ± 1.11 at 1 month and 1.92 ± 0.80 at 6 months (p < 0.001). The most common complication was facial numbness (32%), followed by masticator weakness (14%), dysesthesia (6%), hematoma (2%) and pain recurrence occurred in 6% of cases, defined by either an increase in VAS ≥ 4 or the need for a second intervention during the follow-up window.

Conclusion: Radiofrequency rhizotomy offers effective, well-tolerated pain relief for trigeminal neuralgia with high patient satisfaction. It improves symptom control and outcomes, though further long-term studies are needed to assess sustained benefits and quality-of-life impacts beyond six months.

Background: While chronic neuropathic pain is characterised by abnormal pain signs, such as allodynia, highly disabling co-morbidities, such as anxiety and depression, have a major impact. It is thought that these co-morbidities arise from learning maladaptations related to inappropriate associations between pain and stimulus/environmental cues. However, the impact of animal neuropathic pain models on the interactions between fear-learning, pain and anxiety are poorly understood, particularly during early stages prior to establishment of anxiety.

Methods: We examined the impact of fear-conditioning on fear, anxiety-like behaviours and cold/mechanical allodynia in the mouse sciatic nerve chronic constriction injury (CCI) model of neuropathic pain, at an early post-injury time point.

Results: At 2 weeks post-surgery, CCI and sham operated mice displayed similar acquisition of fear-like freezing responses to a paired audio-tone/footshock fear-conditioning paradigm. On the following day, CCI mice displayed greater freezing than sham mice in response to the same context and subsequent tone presentations. While CCI and sham mice display similar anxiety-like behaviour in the light-dark box and open field, these were increased by fear-conditioning in CCI but not mice. Finally, CCI but not sham surgery produced cold and mechanical allodynia, however, these were unaffected by fear-conditioning.

Conclusions: These findings indicate that a neuropathic pain model enhances learned context/cue evoked fear behaviours at an early stage following nerve-injury. Furthermore, fear-conditioning enhances anxiety-like behaviour, before such behaviour is normally developed. Thus, fear-conditioning induces exaggerated fear-learning which triggers enhanced fear and anxiety, even during early stages of chronic neuropathic pain.

Background: This study aimed to examine the efficacy and safety of ultrasound (US)-guided superior cervical ganglion (SCG) block in conjunction with standard triptan in the management of migraine attacks.

Methods: In total, 243 subjects who received an adjunctive US-guided SCG block alongside triptan for a migraine attack were enrolled as the SCG cohort. A 1:1 propensity score based on baseline covariates was used to match 243 cases who received triptan alone as the control. The primary endpoints were pain relief and freedom from pain within 24 h after the procedure. Secondary outcomes included headache relief and freedom from pain within 2 h, monthly migraine days (MMDs), Migraine Disability Assessment (MIDAS) scores, Migraine-Specific Quality of Life questionnaire (MSQ) scores, and adverse events.

Results: The rates of pain relief and freedom from pain at 24 h after the block were increased in the SCG cases compared to the controls {73.3% vs. 49.4%, with mean difference [MD] of 23.9% [95% confidence interval (CI): 15.5%-29.0%] and 64.2% vs. 37.4%, with MD = 26.7% [95% CI: 18.2%-31.3%], respectively}. Superiority was met, as the 95% CI fell within the superiority margin of 15%. Higher rates of pain relief and freedom from pain at 2 h following the procedure were reported in the SCG cohort (both p < 0.001). At the 1-month follow-up, the SCG cohort had a greater improvement in MMDs (p < 0.01), MIDAS scores (p = 0.040), and MSQ scores (p = 0.036). There were no severe adverse events in the SCG group.

Conclusions: US-guided SCG block with triptan was superior to triptan alone in achieving headache remission during a migraine attack for up to 24 h, resulting in reduced migraine days and improved functional ability and life quality at the 1-month follow-up.

Annually, millions of humans and animals suffer from chronic and acute pain, creating welfare and quality of life concerns for both humans and animals who suffer this pain. In developing new therapeutic approaches, the challenge is to accurately measure this pain to ascertain the efficacy of novel therapeutics. Additionally, there is a need to develop new and effective analgesic options that may offer alternatives to using opioids that contribute to the opioid epidemic. The Pain in Animals Workshop (PAW) meetings are held every other year in partnership with the National Institutes of Health (NIH), bringing key stakeholders together to understand pain in humans and animals better. The 2023 workshop focused on presenting and discussing updates on validated approaches to measuring pain, highlighting opportunity areas for additional outcome measure development. It also discussed study design and analytic approaches to the use of outcome measures in clinical trials, including the important concepts of success-failure approaches and the application of multiple endpoints in evaluating analgesic therapies. The workshop also introduced the concept of the biopsychosocial model of pain, broadening the conversation around the impact of pain and thus opportunities to modulate the pain experience. The application of artificial intelligence to the measurement of pain was introduced. The workshop brought together academia, government, and industry experts in human and animal pain assessment and analgesic intervention development. Given the topic's importance and the meeting's uniqueness, capturing the thoughts and ideas presented and discussed is critical. This narrative is one product from that meeting, summarizing several presentations from the workshop.