Pain

New-onset chronic pain is a common and debilitating symptom of Long COVID (LC) that remains not fully understood in terms of pathophysiology and therapeutic targets. A growing body of evidence in chronic pain syndromes similar to LC demonstrates an association between EEG alpha oscillatory activity and the experience of pain, with clinical studies showing maladaptive changes in oscillatory activity, particularly a slowing of alpha activity. This study aims to investigate the association between ...

IntroductionChronic pain in fibromyalgia may be driven by abnormal ongoing activity in a subclass of C-fibre nociceptors known as Type1B or CMi nociceptors. As is common in C-nociceptor microneurography studies, the modest patient numbers in these prior studies generate large confidence intervals around the point estimate of the prevalence of this abnormal activity. This complicates the interpretation of the relative importance of this ongoing nociceptor activity as a pain generating mechanism i...

Chronic pain (CP) is a multidimensional condition characterized by physical, emotional, and cognitive symptoms. However, many neuroimaging studies investigating the brain mechanisms of CP have focused on single-domain measures, most commonly pain intensity. Incorporating multidimensional symptom profiles may advance the understanding of CP, its neural underpinnings, and the development of clinically actionable biomarkers. Here, we aimed to empirically derive symptom dimensions of CP and relate t...

BackgroundNeuropathic pain (NP) is a debilitating chronic pain condition caused by injury or disease of the somatosensory nervous system. Accumulating evidence indicates that astrocytes play a central role in neuroinflammatory regulation and synaptic remodeling, thereby critically influencing the initiation and persistence of neuropathic pain. However, a comprehensive overview of research trends and knowledge structures in this field is still lacking. MethodsThe analysis was conducted based on ...

Sensory gating -- the brains ability to filter out repetitive sensory input -- is essential for preventing sensory overload. Impaired gating is frequently observed in nociplastic and other chronic overlapping pain conditions, yet the specific brain regions supporting this inhibitory process in humans remains unclear. Neuroimaging studies examining pain processing implicate the anterior insula (AI), posterior insula (PI), and anterior mid-cingulate cortex (aMCC), but their deeper locations limit ...

BackgroundPersistent Spinal Pain Syndrome (PSPS) type II represents a challenging clinical entity with limited therapeutic options. Various spinal cord stimulation (SCS) modalities have emerged as potential treatments, but their comparative effectiveness remains unclear. ObjectiveOur goal in this paper is to systematically evaluate and compare the efficacy of different SCS modalities in patients with PSPS type II through meta-analysis of available randomized controlled trials. Evidence ReviewW...

In this randomized, double-blind, controlled trial of 8 weeks of repetitive transcranial magnetic stimulation (rTMS) for chronic pain, we compared the classic primary motor cortex (M1) rTMS with a novel target-selection strategy based on pre-therapy cortical connectivity. Guided by principles of homeostatic plasticity, we tested whether stimulating the cortical site with the lowest pre-therapy global connectivity would be more effective than two active comparators: stimulating the site with the ...

Repetitive transcranial magnetic stimulation (rTMS) of non-motor cortical targets, including the left dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), and posterosuperior insula (PSI), has been proposed as a treatment for chronic pain with variable clinical outcomes. Pre-treatment local cortical dynamics were hypothesized to serve as markers of chronic pain reduction. In this secondary analysis of a large clinical trial comparing different rTMS targets for pain relief, it...

Resting-state electroencephalography (EEG) has been proposed as a scalable source of biomarkers for chronic pain, but its clinical potential remains uncertain. To systematically evaluate this potential, we benchmarked nine modeling strategies, spanning conventional machine learning with handcrafted features to state-of-the-art deep learning. Across 72 configurations of signal representations and model architectures, we trained models to predict self-reported pain intensity, using chronological a...

Why some surgical participants experience pain that extends beyond the original site of injury while others do not remains poorly understood. Both pain intensity and widespread pain contribute to recovery and quality of life, yet their psychosocial correlates are often examined separately. Using data from two large pre-surgical cohorts--participants preparing for knee replacement or thoracic surgery--we examined associations between sociodemographic and psychosocial factors, pain intensity at su...

We performed the first systematic review and meta-analysis of the prevalence of pain with neuropathic characteristics using Bayesian methods to correct prevalence estimates for the use of screening tools with imperfect sensitivity and specificity (CRD42023416845). We searched major databases for national or regional epidemiological studies that reported the prevalence of pain with neuropathic characteristics, as identified by the PainDETECT, S-LANSS, or DN4-interview. Of the 1,251 unique records...

Two-pore domain potassium (K2P) channels are novel analgesic drug targets with existing in vitro and in vivo validation, however genetic associations in large scale populations have not been widely reported. By examining two comprehensive genetic databases (UK Biobank & FinnGen) and 136 pain-related traits, we highlight that multiple pain-associated signals are present within 500 kb of K2P gene transcripts, with particularly strong evidence for KCNK5 (TASK-2) and headache-related traits. This da...

Chronic pain is increasingly conceptualized within a stress-related framework. However, it remains unclear whether chronic pain and prototypical stress-related conditions--such as post-traumatic stress disorder (PTSD)--share common neurobiological substrates. To this end, we conducted a pre-registered transdiagnostic meta-analytic study of gray matter volume alterations in chronic pain (60 studies) and PTSD (20 studies). Disorder-specific meta-analyses revealed that chronic pain was associated w...

BackgroundPatients understanding of pain and its biopsychosocial nature is thought to be important in order to optimize treatment decisions and treatment outcomes. A validated Spanish questionnaire for patients based on a biopsychosocial model assessing knowledge and attitudes of pain was unavailable. The aim of this study is to validate the Spanish version of the PACKA, to have a Spanish questionnaire to be used among pain patients in both clinical and research settings. MethodsPhase 1: forwar...

BackgroundChronic pain affects 28 million UK adults. While physiotherapy and social prescribing are recognised as effective, evidence on integrating them remains limited. Digital biomarkers could objectively assess movement quality and pain physiology to support clinical decision-making. ObjectivesTo explore whether simple kinematic and electroencephalography (EEG) biomarkers can discriminate between correct versus incorrect exercise performance and high versus low pain states, and to consider ...

BackgroundUnderstanding the associations among biopsychosocial factors is essential for improving research and treatment of chronic low back pain (CLBP). Here we characterized interrelations among biopsychosocial domains using network analysis and identified the most influential features in CLBP. MethodsData came from Quebec Low Back Pain Study, comprising 4,489 CLBP participants. We modeled relationships among baseline biopsychosocial features as networks, where nodes represent features and ed...

Acute pain in hospitalised patients is common and is associated with adverse outcomes, yet African data are scarce. We conducted an international prospective point-prevalence study of adult inpatients across Africa to determine pain prevalence and severity, and explored associations with critical illness and survival status. On a single day, investigators assessed patients worst pain in the preceding 24 hours using a 0-10 visual-numerical scale and recorded vital signs. Critical illness was defi...

AimWe investigated the heterogeneity of treatment effects in transcranial direct current stimulation (tDCS) with mindfulness-based meditation (MBM) and within each individual study group (tDCS alone, MBM alone, and sham) among individuals with symptomatic knee osteoarthritis. We also explored participant characteristics underlying this heterogeneity. MethodsThis secondary analysis drew on a double-blind, randomized, sham-controlled, phase II, parallel-group trial in which 200 participants were ...

Inflammatory pain is a major clinical challenge, yet appropriate human models mimicking local infection are lacking. We established a novel human pain model based on intradermal administration of lipopolysaccharide (LPS), a component of Gram-negative bacteria, and investigated the time course and underlying molecular mechanisms of inflammatory pain hypersensitivity. In a placebo-controlled pilot study with 12 healthy subjects, the intradermal LPS injection induced hyperaemia peaking at 4.5 h and...

IntroductionPatients undergoing anterior cruciate ligament (ACL) reconstruction experience substantial postoperative pain, which delays recovery and leads to both immediate and long-term opioid use. In other knee procedures, infiltration between the popliteal artery and the capsule of the posterior knee (IPACK) has demonstrated analgesic and opioid reducing effects. However, the effect in patients undergoing ACL reconstruction has not been investigated. We aimed to investigate the real-world eff...