Search

Background and Aims: Healthy women have generally been found to have increased experimental pain perception and chronic pain has a higher prevalence in female as compared to male patients. However, no study has investigated whether pain intensity and pain perception thresholds are distinct or similar between sexes within various chronic pain entities. We investigated whether average pain intensities and pain thresholds assessed using quantitative sensory testing (QST) differed between women and men suffering from three distinct chronic pain conditions: Complex Regional Pain Syndrome (CRPS type I), peripheral nerve injury (PNI) or polyneuropathy (PNP), as compared to paired healthy volunteers., Methods: QST data of 1,252 patients (669 female, 583 male) with PNI (n = 342), PNP (n = 571) or CRPS (n = 339), and average pain intensity reports from previously published studies were included. Absolute and z-values (adjusted for age and body region) of cold, heat, pressure (PPT) and pinprick pain thresholds were compared in generalized linear models with aetiology, duration of underlying pain disease and average pain intensity as fixed effects., Results: Average pain intensity during the past four weeks did not differ between women and men, in both mean and range. In women absolute pain thresholds for cold, heat and pinprick were lower than in males across all diagnoses (p < .05). However, after z-transformation these differences disappeared except for PPT in CRPS (p = .001)., Discussion: Pain thresholds in patients show only minor sex differences. However, these differences mimic those observed in healthy subjects and do not seem to be linked to specific pathophysiological processes., Significance: Female healthy participants and female patients with neuropathic pain conditions or CRPS I report lower pain thresholds compared to males, but pain intensity is similar and there is no sex difference in the extent to which the thresholds are altered in neuropathic pain or CRPS. Thus, the sex differences observed in various chronic pain conditions mimic those obtained in healthy participants, indicating that these differences are not linked to specific pathophysiological processes and are of minor clinical relevance., (© 2020 European Pain Federation - EFIC®.)

Background: Thermo-test devices are rarely used outside specialized pain centres because of high acquisition costs. Recently, a new, portable device ("Q-Sense") was introduced, which is less expensive but has reduced cooling capacity (20°C). We assessed the reliability/validity of the "Q-Sense" by comparing it with the Thermal Sensory Analyzer (TSA)., Methods: Using a phantom-skin model, the physical characteristics of both devices were compared. The clinical performance was assessed in a multicentre study by performing Quantitative Sensory Testing (QST) in 121 healthy volunteers and 83 diabetic patients (Eudra-Med-No. CIV-12-05-006501)., Results: Both device types showed ~40% slower temperature ramps for heating/cooling than nominal data. Cold/warm detection thresholds (CDT, WDT) and heat pain thresholds (HPT) of healthy subjects did not differ between device types. Cold pain thresholds (CPT) were biased for Q-Sense by a floor effect (p < .001). According to intraclass correlation coefficients (ICC), agreement between TSA and Q-Sense was good/excellent for CDT (ICC = 0.894) and WDT (ICC = 0.898), moderate for HPT (ICC = 0.525) and poor for CPT (ICC = 0.305). In diabetic patients, the sensitivity of Q-Sense to detect cold hypoesthesia was reduced in males >60 years. Moderate correlations between thermal detection thresholds and morphological data from skin biopsies (n = 51) were similar for both devices., Conclusions: Physical characteristics of both thermo-test devices are similarly limited by the poor temperature conduction of the skin. The Q-Sense is useful for thermal detection thresholds but of limited use for pain thresholds. For full clinical use, the lower cut-off temperature should be set to ≤18°C., Significance: High purchase costs prevent a widespread use of thermo-test devices for diagnosing small fibre neuropathy. The air-cooled "Q-Sense" could be a lower cost alternative, but its technical/clinical performance needs to be assessed because of its restricted cut-off for cooling (20°C). This study provides critical information on the physical characteristics and the clinical validity/reliability of the Q-Sense compared to the "Thermal Sensory Analyzer" (TSA). We recommend lowering the cut-off value of the Q-Sense to ≤18°C for its full clinical use., (© 2019 European Pain Federation - EFIC®.)

This paper presents the results of a prospective observational cohort study investigating referral practices to six specialized pain centres (SPCs) in 303 patients with headache (HD), low back pain (LBP), and neuropathic pain (NP). The study was divided into three parts. Part 1: The pain health care history (contacts with general practitioners and specialists, further referrals, time spans, therapies) before first contact with the SPC. Part 2: Reality of pain therapy and management in the SPC (patients' attrition, interdisciplinarity of therapy and novel therapeutic strategies instigated). Part 3: Follow-up and assessment of pain levels (NRS, SES), disability scores (PDI), QoL scores (SF 12), and anxiety and depression scores (HADS) at 0, 6 and 12 months. Using an ordinal linear regression model, factors predicting a good treatment outcome were identified. On average it took 3 years of pain symptoms before first consultation with GP. The median time period from the first pain sensations until the appointment in the SPC was 12 years. Nearly half of the referrals to specialists or SPCs were initiated by a non-professional. In the SPC the medication was changed in 71% of cases. Care was interdisciplinary in only 32%. At 6 and 12 months after the first contact with the SPC, only 20% of the patients had improved with respect to levels of pain and psychometric data. A high degree of chronicity, a history of pain-associated surgeries and low social support were negative predictors for treatment outcome., (Copyright 2009 European Federation of International Association for the Study of Pain Chapters. Published by Elsevier Ltd. All rights reserved.)