European Journal of Pain最新文献

Background: This study assessed the effect of expectation of analgesia on conditioned pain modulation (CPM) in healthy participants stratified into inhibitors and non-inhibitors.

Methods: A parallel CPM protocol was assessed on 21 women and 22 men across two sessions: baseline and expectation of analgesia, which was induced by a standardized audiovisual suggestion. The CPM assessment involved two different test stimuli (TS): mechanically controlled palpation and the pressure pain threshold, applied to two different regions: anterior temporalis and thenar eminence of the hand. The conditioning stimulus (CS) involved immersing the non-dominant forearm in cold water. The order of the TS and regions was randomized for each participant. The CPM protocol was performed three times, with a 1-min interval between TS/region sequences. After a 20-min rest, the CPM assessment was repeated (two blocks in total). The standard error of measurement (SEM) was computed to identify inhibitors (inhibitory responses) and non-inhibitors (including non-inhibitors and facilitatory responses). Cochran's Q, ANOVA and ANCOVA were applied to the data (p < 0.05).

Results: There was a significant decrease in the proportion of non-inhibitors during the expectation of analgesia session (32.6%-44.2%) when compared with the baseline session (51.2%-72.1%). The non-inhibitors exhibited a lower inhibitory CPM magnitude than the inhibitors only in block 1 of the baseline session. The expectation of analgesia resulted in an increased magnitude of the inhibitory CPM solely in non-inhibitors.

Conclusion: Expectation of analgesia can increase the inhibitory response of the CPM beyond the measurement error in healthy participants with a baseline non-inhibitory profile.

Significance: Several studies have investigated whether cognitive modulation can alter the magnitude of the inhibitory response of conditioned pain modulation (CPM), yet some gaps remain. This study accounted for measurement error to accurately determine changes in CPM influenced by expectation of analgesia.

Background: Hypermobility Spectrum Disorder (HSD) and Hypermobile Ehlers-Danlos Syndrome (hEDS) are two overlapping heritable connective tissue disorders characterized by joint hypermobility, chronic pain, impaired body perception, and musculoskeletal symptoms. Central sensitization has been proposed as a plausible explanation for symptoms like widespread pain, fatigue, mood disorders, and sleep disturbances in patients with HSD/hEDS.

Objective: The aim of this study was to investigate signs of central sensitization, including exercise-induced hypoalgesia (EIH), and fatigue severity in adolescents with HSD/hEDS.

Methods: In this prospective, experimental, case-control study, thirty-seven adolescents with HSD/hEDS and 47 healthy adolescents (all aged 13-17 years) were included. Pressure pain thresholds (PPTs) were measured at four muscle groups using a pressure algometer. EIH was evaluated by measuring PPTs on two muscle groups immediately after an exercise test on a bicycle ergometer. Participants also completed questionnaires on fatigue and cognitive/emotional factors.

Results: The study demonstrated significantly lower PPTs in four different muscle groups in adolescents with HSD/hEDS compared to the healthy control group. Both groups achieved a significantly higher PPTs after exercise in the muscle involved in the activity. Adolescents with HSD/hEDS reported higher fatigue levels and more cognitive/emotional difficulties than the control group.

Conclusion: Adolescents with HSD/hEDS showed generalized hyperalgesia measured through PPTs at different body sites. EIH was partly affected in adolescents with HSD/hEDS, presenting as unchanged pain sensitivity in the remote muscle. Pain should be considered as a phenomenon that is influenced by different biopsychosocial factors, including possible central sensitization, which increase its complexity.

Significance statement: This study breaks new ground by showing signs of central sensitization, including diminished EIH, in adolescents with HSD or hEDS. Given that exercise is a key element in pain management, these findings offer valuable insights when developing treatment plans for adolescents with HSD or hEDS.

Background and objective: While the development of artificial intelligence (AI) technologies in medicine has been significant, their application to acute and chronic pain management has not been well characterized. This systematic review aims to provide an overview of the current state of AI in acute and chronic pain management.

Databases and data treatment: This review was registered with PROSPERO (ID# CRD42022307017), the international registry for systematic reviews. The search strategy was prepared by a librarian and run in four electronic databases (Embase, Medline, Central, and Web of Science). Collected articles were screened by two reviewers. Included studies described the use of AI for acute and chronic pain management.

Results: From the 17,601 records identified in the initial search, 197 were included in this review. Identified applications of AI were described for treatment planning as well as treatment delivery. Described uses include prediction of pain, forecasting of individualized responses to treatment, treatment regimen tailoring, image-guidance for procedural interventions and self-management tools. Multiple domains of AI were used including machine learning, computer vision, fuzzy logic, natural language processing and expert systems.

Conclusion: There is growing literature regarding applications of AI for pain management, and their clinical use holds potential for improving patient outcomes. However, multiple barriers to their clinical integration remain including lack validation of such applications in diverse patient populations, missing infrastructure to support these tools and limited provider understanding of AI.

Significance: This review characterizes current applications of AI for pain management and discusses barriers to their clinical integration. Our findings support continuing efforts directed towards establishing comprehensive systems that integrate AI throughout the patient care continuum.

Background: Chronic pain is among the leading causes of disability worldwide, of which only a small percentage of patients receive adequate treatment for. Non-prescribed opioid analgesics are commonly sought out in effort to alleviate unrelieved pain. This study assesses the prevalence and correlates of chronic pain among primary fentanyl users.

Methods: A cross-sectional and structured survey was conducted with 200 adults who reported fentanyl as their drug of choice from a Vancouver acute care hospital. Presence and levels of chronic pain were determined through self-report.

Results: The majority of participants (n = 130, 72.6%) reported having chronic pain in the past 6 months, with the mean level of pain on a typical day to be 7.6 out of a scale of 10 (SD = 1.9). Majority (n = 85, 65.4%) reported using street opioids to self-medicate, while only 9 (6.9%) reported that their chronic pain was unrelated. Regression analysis indicated that increasing age and co-use of cannabis and opioids were independent associated factors of chronic pain. Higher levels of reported pain on a typical day were further associated with age and self-medication.

Conclusions: The findings of this study demonstrate a significant association between self-medication and chronic pain among primary fentanyl users in British Columbia. For these individuals, inadequate pain relief may drive continued opioid use, which in turn may increase risks of treatment discontinuation and overdose. Appropriate pain management strategies are crucial to avoid opioid misuse and decrease the large societal burden caused by chronic pain.

Significance: Our work points to the high prevalence of self-reported chronic pain among individuals who primarily use fentanyl. Among those with self-reported fentanyl use and chronic pain, self-medication with street opioids was found to be common and associated with higher reported pain levels on a typical day. This highlights the need for pain management strategies to be integrated into opioid dependence treatment and more research in the overlap of pain and fentanyl use.

Background: Plasma neurofilament light chain (NFL) has been measured as a biomarker of neuronal damage in various neurological disorders. Elevated tau and β-amyloid levels have been found in patients with fibromyalgia (FM). The aim of the present study was to compare plasma neurofilament levels in fibromyalgia patients with normal controls and to investigate the correlation with clinical features and cognitive tests.

Methods: Plasma NFL levels were assessed in 33 FM patients and compared with 22 age-matched controls. All patients were also assessed with clinical scales examining fibromyalgia disability, sleep quality and duration, fatigue, anxiety, and depression, and a neuropsychological battery examining executive function, verbal short-term memory, and working memory, as well as attentional executive function and selective attention, interference sensitivity, and inhibition of automatic responses.

Results: NFL levels were higher in FM patients (controls 6.19± 1.92; FM 17.28± 15.94 pg/mL ANOVA p 0.002). Working memory was the most impaired cognitive function significantly correlated with high NFL scores (Pearson p 0.034). Short sleep times also correlated with higher NFL scores (Pearson p 0.02) and poorer working memory performance (Pearson p 0.02). No correlation was found with indices of disease severity and duration.

Conclusions: Plasma NFL levels are elevated in fibromyalgia patients, suggesting neuronal damage and correlating with a slight decrease in working memory and short sleep duration.

Significance statement: Plasma neurofilament levels are elevated in patients with fibromyalgia, regardless of disease severity and duration. Neurofilament levels are higher in patients with mild working memory impairment and sleep disorders. Subgroups of patients with primary neuronal damage phenomena could be individualized for prospective evaluation with regard to the possible development of cognitive decline and sleep disturbances, which would justify a tailored therapeutic approach.

Background: Persistent postsurgical pain (PPSP) following thoracic surgery affects 40%-60% of patients undergoing lung resection due to malignancies. Postoperative pain-related symptoms are common, leading to limitations in activities of daily living (ADL) and deterioration in physical function, which significantly impacts quality of life. Pain-related limitations are of interest, as postsurgical pain may present as a target for intervention to improve postoperative rehabilitation. This study aimed to evaluate the association between PPSP and ADL limitations during the first 12 postoperative months after surgery for lung cancer.

Methods: A total of 124 patients undergoing surgery for lung cancer were followed for 12 months. Every 2 months, participants reported ADL limitations attributed to PPSP. Cumulative pain impairment scores were calculated from reported limitations in 14 daily activities, and recovery trajectory patterns were analysed.

Results: Daily activities most affected by PPSP were carrying bags, arm elevation, climbing stairs, cleaning floors and coughing, with >50% reporting limitations across all assessment times. Reported pain intensities were generally mild (NRS≤3), but still associated with significant impairment. Some recovery was observed in patients reporting pain at rest, but PPSP was consistently associated with higher cumulative pain impairment scores at all assessments during the 12-month follow-up period.

Conclusions: Findings indicate that persistent postsurgical pain, even of mild intensity, is associated with significant limitations in daily activities up to 12 months post-surgery. Some improvement in pain-related impairment was observed, although limitations remained significantly higher in patients reporting persistent postsurgical pain, as compared to pain-free patients.

Significance: Surgery remains a cornerstone in the treatment of early-stage lung cancer. Despite advances in minimally invasive techniques and rehabilitation, persisting postsurgical pain and pain-related limitations in daily activities may endure. This study investigated specifically the pain-related limitations in activities of daily living and described recovery trajectories during the first 12 postoperative months. Patients with persistent postsurgical pain experienced multiple limitations compared to pain-free patients. Although partial recovery was observed, impairments remained significant for up to 12 months after surgery.

Background: High-impact chronic pain (HICP), defined as chronic pain with a significant impact on daily function, affects approximately 8% of the Western population. In Denmark, HICP still remains to be described at the population level. Some patients with HICP are referred to the Danish pain centres, where they are registered with a procedural code. We conducted a nationwide registry-based study of all Danish patients registered with a visit to a pain centre from January 2005 to March 2022, to explore time trends in the prescription of analgesics and sedatives in this HICP subpopulation. Furthermore, data on socioeconomics and hospital diagnoses are reported.

Methods: We used data from the Central Person Registry, the Danish National Patient Registry, the Danish National Prescription Registry, combined with data on socioeconomic information from Statistics Denmark. Data was collected on prescriptions 3 months before the first visit to a pain centre. Prescriptions were stratified into five calendar periods: before 2011, 2011-2013, 2014-2016, 2017-2019, and 2020-2022.

Results: We identified 66,577 patients referred to a pain centre. Over 15 years, prescriptions before referral declined for opioids (from 53.2% to 31.7%), NSAIDs (from 28.3% to 23.5%), antidepressants (from 20.5% to 16.8%), anxiolytics (from 12.3% to 3.2%), and sleep medication (from 15.8% to 7.6%). In contrast, prescriptions increased for paracetamol (from 31.1% to 48.9%) and gabapentinoids (from 19.2% to 27.7%).

Conclusions: In patients with HICP visiting Danish pain centres, prescriptions before referral decreased for opioids over 15 years, with a simultaneously increased prescription of gabapentinoids (gabapentin and pregabalin).

Significance statement: This nationwide study of 66,577 Danish patients with high-impact chronic pain reveals a significant decrease in filled opioid prescriptions over the past 15 years, with a simultaneous rise in gabapentinoid use before referral to pain centres. These findings suggest a shift in clinical practice towards alternative pain management strategies. The study underscores the need for continued research into the long-term effects of these changes and their impact on patient outcomes.

Background: Stretching exercises have effects on local and widespread pain sensitivity. A dose-response relationship may exist between the analgesic effect and the intensity of stretching, such that a higher intensity of stretching may generate a larger reduction in analgesic response, but this remains to be studied. This study aimed to examine the dose-response relationship between stretching intensity and the analgesic effect.

Methods: A randomized, repeated-measures crossover study was performed to examine the effect of stretching to the first point of pain onset and stretching to the point of a sensation of stretching (discomfort). The primary outcome was regional and distant pressure pain thresholds.

Results: Thirty-one participants (n = 24 female) were available for analysis. We observed a 22.2% increase in regional pressure pain thresholds (93.2 kPa, p = 0.001) and a 15.0% increase in distant pressure pain thresholds (50.9 kPa, p = 0.012) following stretching to the point of stretch. We observed a 20.0% increase in regional pressure pain thresholds (90.3 kPa, p = 0.001) and a 15.1% increase in distant pressure pain thresholds (52.1 kPa, p = 0.004) following stretching to the point of pain.

Conclusions: The results showed that local and widespread pain sensitivity decreased following acute stretching, regardless of stretching intensity. No differences in pain sensitivity were found between stretching to the point of stretch or stretching to the first onset of pain. Thus, the results showed no evidence of a dose-response relationship between stretching intensity and the analgesic effect.

Significance: The study showed a significant acute hypoalgesic effect of stretching exercises regardless of stretching intensity. This may have appropriate clinical implications for patients with musculoskeletal and nociplastic pain.