The objective of this scoping review was to investigate the available literature on physical and quality of life (QoL) outcomes of underwater treadmill exercise trials in clinical chronic pain samples. A scoping search of studies of the effectiveness of underwater treadmill exercise trials from 1947 to 2024 was conducted using the following databases: EMBASE, MEDLINE, SPORTDiscus, CINAHL, and Cochrane Reviews. To be included, studies were required to have included adult participants living with chronic pain (defined as pain lasting for 3 months or longer) who participated in an active underwater treadmill exercise intervention. No restrictions on pain diagnosis were applied. All clinical trials, including but not limited to randomized controlled trials (RCTs), feasibility trials, and pilot studies, were included in the search. Two independent reviewers determined whether studies met inclusion criteria, and a third reviewer resolved any disagreement on study inclusion. The initial search identified 2,209 studies: 314 articles were removed for duplications, 1,781 were removed because they did not meet inclusion criteria, and 113 were retained for full-text review. The full-text review yielded nine studies, all of which included samples consisting of participants with osteoarthritis. The following variables were investigated in the included studies to varying degrees: pain, QoL, mobility, balance, strength, and changes in gait kinematics. Multiple studies identified significant differences between control groups or pre-intervention groups and underwater treadmill groups or post-intervention groups in chronic pain, balance, mobility, strength, and QoL. Findings suggest that underwater treadmill exercise leads to positive changes in chronic pain, balance, mobility, strength, and QoL. However, more studies, particularly RCTs with larger samples that include individuals with chronic pain conditions other than osteoarthritis, are warranted.

The association between baseline laboratory parameters and experienced well-being in healthy individuals remains uncertain. This study explored the relationship between clinical laboratory profiles and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores for pain, stiffness, and physical functional limitation in healthy individuals in Qatar. Clinical laboratory data were collected from 1,764 Qatar Biobank participants who also completed the WOMAC questionnaire: lipid profiles (high-density lipoprotein, low-density lipoprotein, cholesterol, and triglycerides), endocrine markers (TSH, T3, T4, estradiol, and testosterone), and two inflammatory markers (CRP and fibrinogen). Multiple linear regression was used with 11 clinical indicators as independent variables and the subscale and total WOMAC scores as dependent variables. Multivariate effects of each indicator on the outcomes were assessed, and univariate effects were examined when significant. Testosterone had a significant impact on all WOMAC subscales (pain, stiffness, and functional limitation) and the total WOMAC score. Higher testosterone levels were associated with a reduction in pain (β = -0.03, t = -3.505, p < 0.001, 95% CI = -0.052, -0.015), stiffness (β = -0.01, t = -2.265, p = 0.024, 95% CI = -0.018, -0.001), physical dysfunction (β = -0.08, t = -3.265, p = 0.001, 95% CI = -0.135, -0.034), and total WOMAC scores (β = -0.127, t = -3.444, p < 0.001, 95% CI = -0.199, -0.055). Elevated fibrinogen levels were associated with an increase in stiffness (β = 0.155, t = 2.241, p = 0.025, 95% CI = 0.019, 0.290), physical dysfunction (β = 1.17, t = 2.808, p = 0.005, 95% CI = 0.354, 1.997), and total WOMAC scores (β = 1.610, t = 2.691, p = 0.007, 95% CI = 0.437, 2.784). Testosterone may protect against pain, stiffness, and physical dysfunction, while high fibrinogen levels might be a surrogate of systemic inflammation that enhances stiffness and limits physical function. Measuring multiple clinical and laboratory markers in healthy individuals may enhance our understanding of the molecular mechanisms underlying pain.

A significant subset of patients with mental health disorders (MHDs) fail to respond to standard management and are termed as treatment-resistant. This cohort has limited options for managing their condition. Autonomic dysfunction has been reported in the neurobiology of MHDs including anxiety, depression, obsessive-compulsive disorder (OCD), panic disorder, and bipolar disorder (BD). Stellate ganglion block (SGB) is an emerging treatment that dampens sympathetic activity and has been shown to be of benefit in the management of post-traumatic stress disorder. Patients with treatment-resistant disparate MHDs were reviewed by a multidisciplinary team comprising a psychiatrist, a clinical psychologist, and a pain medicine physician. Patients were offered SGB as a novel strategy in the management of treatment-resistant conditions. Validated outcome measures were completed at baseline, 4 weeks, and 16 weeks post-intervention. Four patients with heterogenous treatment-resistant MHDs who received SGB are presented in this report. SGB resulted in an improvement in BD, OCD with alcohol addiction, opioid addiction, and health anxiety. SGB could have a role in the management of treatment-resistant MHDs.

Autonomic regulation has been identified as a potential regulator of pain via vagal nerve mediation, assessed through heart rate variability (HRV). Non-invasive vagal nerve stimulation (nVNS) and heart rate variability biofeedback (HRVB) have been proposed to modulate pain. A limited number of studies compare nVNS and HRVB in persons with chronic pain conditions. This systematic review compared interventions of nVNS and HRVB in adults with long-standing pain conditions. PubMed, MEDLINE, CINAHL, SPORTDiscus, Google Scholar, and Cochrane library were used to retrieve the randomized controlled trials for this review between the years 2010 and 2023. Search terms included chronic pain, fibromyalgia, headache, migraine, vagus nerve stimulation, biofeedback, HRV, pain assessment, pain, and transcutaneous. Ten full-text articles of 1,474 identified were selected for full qualitative synthesis, with a combined population of 813 subjects. There were n = 763 subjects in studies of nVNS and n = 50 subjects for HRVB. Six of the nine nVNS studies looked at headache disorders and migraines (n = 603), with two investigating effects on fibromyalgia symptoms (n = 138) and one the effects on chronic low back pain (n = 22). Of the nVNS studies, three demonstrated significant results in episode frequency, six in pain intensity (PI) reduction, and three in reduced medication use. The HRVB study showed statistically significant findings for reduced PI, depression scores, and increased HRV coherence. Moderate to high-quality evidence suggests that nVNS is beneficial in reducing headache frequency and is well-tolerated, indicating it might be an alternative intervention to medication. HRVB interventions are beneficial in reducing pain, depression scores, use of non-steroidal anti-inflammatory medication, and in increasing HRV coherence ratio. HRVB and nVNS appear to show clinical benefits for chronic pain conditions; however, insufficient literature exists to support either approach.

The efficacy of long-term opioid therapy (LTOT) in treating patients with chronic non-cancer pain (CnCP) is questionable, and the potential risks of adverse effects are well established. The aims were as follows: (1) compare characteristics in patients exposed to LTOT vs non-exposed. (2) Regarding opioid-exposed patients, describe characteristics of patients with risk factors for opioid use disorder or overdose in relation to opioid dosage. A cross-sectional study was conducted at a Swedish tertiary pain rehabilitation clinic serving CnCP patients. The study population comprised 1,604 patients ≥18 years old registered in the Swedish Quality Registry for Pain Rehabilitation between 2018 and 2020. Data on dispensed opioids were extracted from the Swedish Prescribed Drug Register. Dependent variables were as follows: LTOT vs non-LTOT and exposed opioid dosage <50 mg morphine equivalent/day (MME/day) vs ≥50 MME/day. Of the included patients, 681 (42.5%) had at least one dispensation of opioids 180 days prior to assessment, 601 with a calculated opioid dosage ≥1 MME/day, and 424 (26.4%) were exposed to LTOT. The type of opioid prescribed was, in descending order, oxycodone (42.3% of all dispensations), codeine in combination with paracetamol (17.6%), tramadol (13.8%), and morphine (8.1%). A total of 89 cases had dosages of ≥50 MME/day and 430 patient dosages <50 MME/day. Patients exposed to LTOT exhibited an increased odds ratio (OR) of 2.685 (95% CI, 1.942-3.711) for concomitant use of benzodiazepines and male sex (OR, 1.694; 95% CI, 1.227-2.337). Patients receiving doses ≥50 MME/day were all, except one, exposed to LTOT. The concomitant use of benzodiazepines (OR 1.814, 95% CI 1.264-3.331) and male sex (OR, 1.777; 95% CI, 1.178-3.102) indicated a higher OR for opioid doses ≥50 MME/day. LTOT strongly influenced the opioid dose. Furthermore, concomitant benzodiazepine dispensation and male sex were over-represented in patients exposed to LTOT as well as those exposed to opioid doses ≥50 MME/day.

Since 2008, patients have had access to reimbursed analgesics, including opioids, for chronic pain in Norway. There is a need for knowledge on the occurrence and trends over time of substance use disorder (SUD) diagnoses among patients who receive reimbursed opioids for chronic pain. The primary aim of this study was to investigate the prevalence of SUD diagnoses in patients with chronic pain using reimbursed opioids from 2010 to 2019 in Norway. The secondary aim was to investigate the prevalence of other mental health diagnoses among those receiving reimbursed opioids in the subgroups with and without SUD diagnoses. A cross-sectional design utilising data from four Norwegian nationwide registries. The annual number of individuals with SUD diagnoses increased from 377 to 932 from 2010 to 2019, while the annual prevalence of individuals with SUD remained relatively stable at around 5%. There was a higher prevalence for all categories of other mental health diagnoses among individuals with a SUD diagnosis, compared to those without a SUD diagnosis. The prevalence of SUD diagnoses was low in the population using reimbursed opioids for chronic pain in Norway, but the number of patients increased in the study period because the number of individuals receiving reimbursed opioids increased. Patients with a SUD used on average twice the daily doses of opioids compared to patients without a SUD. They were also more likely to have an additional mental health diagnosis.

The overlapping neural networks of social and physical pain have been investigated intensively in recent years. It was postulated that triggering social pain might result in greater physical pain. Nonetheless, how this affects somatoform pain disorder has not yet been considered. Since an increased pain processing activity is reported in these patients, the investigation of social exclusion and its effect on this group seems interesting. Hence, the aim of this study was to compare the influence of social exclusion on healthy controls and patients with somatoform pain disorder. Nineteen patients with somatoform pain disorder and 19 healthy controls were examined. Cyberball, a virtual ball-tossing paradigm, was used to experimentally induce social exclusion and inclusion. To measure effects on pain perception, pressure pain thresholds and heart rate variability (HRV) were recorded after each round of cyberball. Demographic data, pain medication, and potential psychosocial moderators were collected by questionnaires. After social exclusion, pressure pain thresholds were significantly reduced in healthy controls (p < 0.01) as well as somatoform pain patients (p < 0.05), while HRV increased only in patients with somatoform pain disorder (p < 0.05) indicating increased parasympathetic activity. This study is the first to analyse the effects of social exclusion on pain perception in somatoform pain disorder. While the reduction in pressure pain thresholds is in line with the social pain literature, the effects on HRV could be interpreted as a form of pain regulation mechanism. However, further research is needed to investigate the role of parasympathetic activity in socially excluded somatoform pain patients.

Inflexibly relying on avoidance of expression may increase and perpetuate pain-related emotional distress in patients with chronic pain. The context-insensitive avoidance (CIA) scale was recently developed to measure the degree to which patients avoid expressing their pain and distress in social situations. This study explored the psychometric properties of the CIA scale in a new sample. This study uses baseline data from a treatment trial for n = 115 patients with chronic pain and co-occurring emotional distress. Reliability and construct and criteria validity were studied using the same instruments as in the original psychometric study and further explored in two new measures. A series of multiple regression analyses were conducted to assess the relationship between the CIA scale and criteria variables compared to the other psychological constructs. The CIA scale showed good reliability. Significant correlations between high scores on the CIA scale and low scores on self-compassion and activity engagement could be replicated. Significant correlations between high scores on the CIA scale and high scores of pain intensity and pain interference could also be replicated. In the exploring part of this study, validity was extended to general problems with emotion regulation and to satisfaction with life in general and contact with friends but not to satisfaction with family, partner, or sexual life. Avoidance of expression was the only significant predictor of pain intensity. This study could replicate acceptable psychometric properties of a scale measuring CIA of expression. As in the original study, avoidance of expression was associated with increased suffering. Clinically, this instrument may be used to identify patients who may otherwise remain in aggravating silence. Theoretically, it introduces the important concept of context sensitivity to the field of chronic pain. Limitations include uncertainty about causal relationships, and that several important social situations were not examined.

The 13-item pain catastrophizing scale (PCS) is the most commonly used measure of pain catastrophizing. A validated Finnish version of the PCS has previously been unavailable. The objectives were to translate the original English version of the PCS into Finnish (PCS-FI), then to evaluate (i) structural validity of the PCS-FI with a confirmatory factor analysis (CFA), (ii) internal reliability with Cronbach's alpha, Omega, and Omega hierarchical, (iii) convergent validity with measures of well-being, quality of life, sleep quality, symptoms of central sensitization, and anxiety, and (iv) known-groups validity between participants with chronic low back pain (CLBP) and pain-free controls. The translation process was performed with established guidelines. The PCS-FI was psychometrically validated using 92 participants with CLBP and 53 pain-free controls. Structural validity with CFA supported a bifactor solution. However, low reliability was found for the three specific factors (ω h ranging from 0.14 to 0.18) compared to the general factor (ω h = 0.88) suggesting that only the total score should be used. Convergent validity analysis showed satisfactory correlations and medium effect sizes with the other patient-reported outcome measures. Participants with CLBP had significantly higher total PCS-FI scores than pain-free controls. The PCS-FI appears to be a valid and reliable instrument for assessing pain-related catastrophizing in Finnish-speaking populations. Ethical approval for this study was obtained from the Research Ethics Committee of the Northern Savo Hospital District, identification number 2131/2022, on the 31st of January 2022.