Abstract. Introduction:. Painful stimuli trigger autonomic nervous system responses, including changes in pupil size, which provide a physiological measure of pain processing and modulation. The endogenous pain modulatory system plays a key role in regulating pain, and its dysfunction contributes to a variety of chronic pain conditions. Offset analgesia (OA) offers a behavioral measure of this system but relies on subjective ratings. Objectives:. This study aimed to determine whether pupil size can serve as a physiological proxy of OA in healthy individuals, complementing traditional pain ratings. Methods:. Twenty-nine healthy participants completed an OA paradigm applied on the left volar forearm with 3 thermal phases: T1, 47°C for 5 seconds; T2, 48°C for 5 seconds; and T3, 47°C for 20 seconds. Subjective pain intensity was rated verbally (0–10), and pupil size was recorded continuously via infrared pupillometry. Analgesic effects for pain ratings and pupil sizes were quantified by comparing T2 maxima with T3 minima and analyzed using linear mixed-effects models. Results:. Participants showed a strong OA effect, with pain ratings decreasing by 52% (P < 0.001, Cohen d = 2.09). Pupil sizes decreased by 20% (P < 0.001, Cohen d = 1.52), exceeding natural resting-state variability. Pain sensitivity measures were not associated with the amount of pupil size changes during OA. Conclusion:. Pupil size decreased significantly during OA, consistent with the expected analgesic effect. Whether this truly reflects the endogenous pain modulatory system remains to be confirmed in future studies that include a constant-temperature control condition to establish specificity of the observed pupil response.
Blandhol M, Lee S, Ellingsen D-M. Rethinking coping in chronic pain:a systematic review and dynamic interaction model of coping. PAIN Rep 2026;11:e1421. Reply to: de Azevedo Nobre CD, Martins Santiago BV. Surgical resilience may represent the perioperative expression of dynamic adaptive coping. PAIN Rep 2026;11:e1501.
Abstract. Introduction:. Glossopharyngeal neuralgia (GPN) is a rare cranial pain syndrome, with limited comparative long-term evidence for microvascular decompression (MVD) and neurotomy (NT). Objectives:. To compare clinimetric outcomes of microvascular decompression (MVD) and neurotomy (NT) in patients with glossopharyngeal neuralgia (GPN). Methods:. Analytical ambispective multicenter study (1990–2024) including patients with GPN treated with MVD or NT across 3 international neurosurgical centers. Pharmacological treatment history was recorded. Pain intensity was assessed pre- and postoperatively using the Visual Analog Scale (VAS) and Barrow Neurological Institute-Pain Intensity Score. Positive sensory symptoms (PSS) including allodynia, dysesthesia, and paresthesia were evaluated when data were available. Results:. From a total of 93 medical records, 25 patients underwent surgery; 23 met inclusion criteria (MVD = 12, NT = 11) and were evaluated long-term. Patients had a mean age of 58.48 ± 14.33 years, and follow-up ranged from 6 months to 14 years (mean 5.2 ± 4.52). All patients were refractory to pharmacotherapy. Overall VAS scores decreased from 4 to 10 (mode 10) preoperatively to 0 to 5 (mode 0) postoperatively (P = 2.38 × 10−7). In the MVD group, VAS decreased from 4 to 10 to 0 to 5 (P = 0.00049), and in the NT group from 8 to 10 to 0 to 4 (P = 0.00098), with no significant difference in postoperative scores between groups (P = 0.913). Positive sensory symptoms were assessed in 12 patients (52.17%); 9 (75%) presented ≥1 preoperatively (100% allodynia, 77.8% dysesthesia, 22.2% paresthesia). Postoperatively, only 1 patient (8.3%) had persistent dysesthesia and paresthesia. Conclusions:. Both MVD and NT are highly effective in reducing pain and PSS in GPN, with comparable postoperative outcomes. Limitations include small sample size and ambispective design.
Abstract. Shoulder pain is a major cause of work absenteeism, affecting 1 in 3 adults. Although nonsurgical treatments like physical therapy are recommended as the first line of management, 40% of patients are referred for surgery before exploring these options. This review aimed to identify existing triage models used for shoulder pain referrals for surgery, guidelines for shoulder pain management that include criteria for surgical referral, and indications for surgery. An integrative review approach was used to comprehensively search major databases (Medline, PubMed, Embase, CINAHL Plus) and gray literature. Articles on triage models, referral processes, or surgery candidacy for shoulder pain were included. The searches retrieved 4510 articles, with 480 selected for full review and 71 articles included in this synthesis. Thirty-seven articles described various triage models and clinical decision-making processes for managing shoulder pain, including determining when to refer for surgical consultation and the indications for surgery. Seventeen articles compared surgical and nonsurgical treatments to identify surgical indicators, 10 articles examined factors affecting decision-making, and 7 articles explored predictor models for surgical outcomes. The findings underscore the need for a multifactorial decision-making process that acknowledges the complexity of pain within a biopsychosocial framework and incorporates patients' personal preferences into the triage decision-making process. These triage models should work across different contexts, eg, conservative, primary, and speciality care, to facilitate better patient experience across the continuum.
Abstract. Back pain affects over half of individuals with lower limb amputation, yet research findings on associated factors remain fragmented. In view of the evolution of pain science in the general population, this fragmentation likely stems from significant variability in the identification, characterization, and classification of pain, as well as inconsistent assessment of associated biopsychosocial factors. This scoping review aims to examine how back pain is currently identified, assessed, classified, and characterized in people with lower-limb amputation, to determine the gaps and inconsistencies that could impede standardization and evidence synthesis. Six electronic databases were searched for studies involving major unilateral acquired lower limb amputation. Two independent reviewers screened articles and extracted data using standardized forms in Covidence. Synthesis focused on identification, classification, reporting of back pain–related biopsychosocial variables, and assessment strategies. Sixty-seven studies were included, predominantly cross-sectional (69%). Although pain intensity was frequently assessed, methods were binary (yes/no), and the use of mechanistic classification and biopsychosocial factors was sparse. Measurement strategies were highly heterogeneous, with standardized frameworks used in only 4 studies. This scoping review reveals a profound discrepancy between contemporary pain science approaches and current pain practice methodologies for the lower limb amputation population. Significant diagnostic gaps persist because of inconsistent classification of pain mechanisms and a void in reporting biopsychosocial variables. Prioritizing standardized frameworks and a population-specific core outcome set is essential to bridge the translational gap. These advancements will improve research quality and facilitate more targeted, evidence-based clinical care for this complex population.
