Predicting Factors of Pain Duration in Patients with Chronic Pain: A Large Population-based Study

The synergistic anti-nociceptive effects of nefopam and gabapentinoids in inflammatory, osteoarthritis, and neuropathic pain mouse models

Pain is a common public health problem and remains as an unmet medical need. Currently available analgesics usually have limited efficacy or are accompanied by many adverse side effects. To achieve satisfactory pain relief by multimodal analgesia, new combinations of nefopam and gabapentinoids (pregabalin/gabapentin) were designed and assessed in inflammatory, osteoarthritis and neuropathic pain. Isobolographic analysis was performed to analyze the interactions between nefopam and gabapentinoids in carrageenan-induced inflammatory pain, mono-iodoacetate-induced osteoarthritis pain and paclitaxel-induced peripheral neuropathic pain in mice. The anti-inflammatory effect and motor performance of monotherapy or their combinations were evaluated in the carrageenan-induced inflammatory responses and rotarod test, respectively. Nefopam (1, 3, 5, 10, 30 mg/kg, p.o.), pregabalin (3, 6, 12, 24 mg/kg, p.o.) or gabapentin (25, 50, 75, 100 mg/kg, p.o.) dose-dependently reversed mechanical allodynia in three pain models. Isobolographic analysis indicated that the combinations of nefopam and gabapentinoids exerted synergistic anti-nociceptive effects in inflammatory, osteoarthritis, and neuropathic pain mouse models, as evidenced by the experimental ED50 (median effective dose) falling below the predicted additive line. Moreover, the combination of nefopam-pregabalin/gabapentin alleviated carrageenan-induced inflammation and edema, and also prevented gabapentinoids-related sedation or ataxia by lowering their effective doses. Collectively, the co-administration of nefopam and gabapentinoids showed synergistic analgesic effects and may result in improved therapeutic benefits for treating pain.

Pain relief and associated factors: a cross-sectional observational web-based study in a Quebec cohort of persons living with chronic pain

Objectives

Randomized clinical trials are used to evaluate the efficacy of various pain treatments individually, while a limited number of observational studies have portrayed the overall relief experienced by persons living with chronic pain. This study aimed to describe pain relief in real-world clinical settings and to identify associated factors.

Methods

This exploratory web-based cross-sectional study used data from 1,419 persons recruited in the community. Overall pain relief brought by treatments used by participants was assessed using a 0%-100% scale (10-unit increments).

Results

A total of 18.2% of participants reported minimal pain relief (0%-20%), 60.0% moderate to substantial pain relief (30%-60%), and 21.8% extensive pain relief (70%-100%). Multivariable multinomial regression analysis revealed factors significantly associated with greater pain relief, including reporting a stressful event as circumstances surrounding the onset of pain, living with pain for ≥10 years, milder pain intensity, less catastrophic thinking, use of prescribed pain medications, use of nonpharmacological pain treatments, access to a trusted healthcare professional, higher general health scores, and polypharmacy. Factors associated with lower pain relief included surgery as circumstances surrounding pain onset, use of over-the-counter pain medications, and severe psychological distress.

Discussion

In this community sample of persons living with chronic pain, 8 out of 10 persons reported experiencing at least moderate relief with their treatment. The analysis has enabled us to explore potential modifiable factors as opportunities for improving the well-being of persons living with chronic pain.

The relationship between sleep disturbances and endometriosis: A systematic review

OBJECTIVE

Endometriosis is associated with a range of symptoms that can negatively impact a person's quality of life. While pain and infertility have received at lot of attention, sleep disturbances in individuals with endometriosis has been overlooked in both clinical practice and research. Therefore, the primary aim of this systematic review was to gather evidence from the current literature to illustrate the association between sleep disturbances and endometriosis.

STUDY DESIGN

A literature search was conducted using three electronic databases (OVID EMBASE, MEDLINE, and Web of Science). Observational studies, published in English, that involved participants aged 18 years or older that compared sleep outcomes between endometriosis patients and those without a history of endometriosis were included. The quality of each study was assessed using the Joanna Briggs Institute critical appraisal tools.

RESULTS

Nine studies (six case-control and three cross-sectional) were included in this review; 7 with low risk of bias and 2 with moderate risk of bias. The studies demonstrated heterogeneity in the assessment of sleep disturbances. However, 7 studies reported a significant positive association between endometriosis and sleep disturbances. Moreover, this impact on sleep was further complicated by the complex interaction between pain, fatigue and quality of life.

CONCLUSION

Current studies suggest an association between sleep disturbances and endometriosis, which may provide a blueprint for future clinical recommendations to screen and treat sleep disturbances in individuals with endometriosis to improve their quality of life. Future studies should aim to standardise the methods of assessing sleep disturbances and explore potential contributing factors.

The effect of different regional analgesia methods on chronic pain after thoracic surgery

Introduction

Chronic postsurgical pain (CPSP) is defined as pain persisting for ≥ 3 months after surgery, severely impairing patients' long-term daily activities and quality of life.

Aim

To evaluate the effects of various regional analgesia methods, including thoracic epidural (TE), serratus anterior plane (SAP) block, rhomboid intercostal block (RIB) and paravertebral block (PVB), on the incidence of chronic post-thoracic surgery pain.

Material and methods

A total of 489 patients (240 thoracotomy, 249 VATS) were included in the analysis. The primary outcome measure was the VAS score (postoperative 6th month), while the secondary outcome measures were the LANSS score (postoperative 6th month), the use of analgesic medication and descriptive information.

Results

In thoracotomy patients, VAS scores were statistically significantly lower in patients who underwent RIB and SAP block compared to those who underwent TE and patient-controlled anesthesia (PCA). LANSS scores did not differ between the RIB, SAP and TE groups, while higher scores were found in the PCA group. After VATS, VAS scores were statistically significantly lower in patients who underwent RIB, SAP and PVB block compared to the PCA group. LANSS scores were statistically significantly lower in the RIB and SAP block groups than in the PVB and PCA groups.

Conclusions

This study found that patients who received regional anesthesia had lower LANSS scores and VAS values, indicative of neuropathic pain reduction, following thoracotomy and VATS procedures.

Pain-Related Cognitive Processes, Pain Interference, and Alexithymia in Patients With Primary Headaches

Objectives This study aims to investigate the effects of pain-related cognitive processes (PRCPs) and emotional state on pain-related disability (PRD) and pain interference (difficulty in performing daily routines, difficulty in engaging in social activities [the enjoyment of life], and the impact on work and/or school performance) in patients with primary headaches (PHs). Methodology PRCPs were evaluated with the Pain Anxiety Symptom Scale-20 (PASS-20), Pain Catastrophizing Scale (PCS), and Pain Belief Questionnaire (PBQ). Anxiety, depression, and alexithymia were investigated to assess the emotional state. PRD was assessed by Headache Impact Test-6 (HIT-6). Health-related quality of life (HRQoL) was evaluated under three headings: daily activities (with Short Form-36 [SF-36] Question [Q] 22), social activities (with Graded Chronic Pain Scale-Revised [GCPS-R] Q 4), as well as the working ability (with GCPS-R Q 5). Two separate models were constructed to identify the factors influencing PRD and HRQoL in PHP: M1 to reveal the factors affecting PRD and M2 to determine the independent factors affecting pain interference. In both models, correlation analysis was applied first and the significant data were then evaluated with regression analysis. Results A total of 364 participants (74 healthy controls [HCs] and 290 PHPs) completed the study. In M1, the following domains were significantly associated with PRD: cognitive anxiety (β = 0.098; 95% confidence interval [CI] = 0.001-0.405; P = 0.049); helplessness (β = 0.107; 95% CI = 0.018-0.356; P = 0.031); alexithymia (β = 0.077; 95% CI = 0.005-0.116; P = 0.033); depression (β = 0.083; 95% CI = 0.014-0.011; P = 0.025). In M2, factors associated with impairment in daily activities for PHP were as follows: duration of pain, pain intensity, alexithymia, escape-avoidance response, psychological anxiety, anxiety, and poor sleep quality (R = 0.770; R² = 0.588). The independent factors affecting social activities for PHP were pain intensity and pain-related anxiety (R = 0.90; R² = 0.81). Independent risk factors that affected the ability to work for PHP were pain intensity, cognitive anxiety, escape-avoidance response, and pain anxiety (R = 0.90; R² = 0.81). Conclusions This study highlights the importance of cognitive and emotional processes that help increase our understanding of the patient with PHs. This understanding may help to reduce disability and improve the quality of life in this population by helping to guide multidisciplinary treatment goals.

High-impact chronic pain: evaluation of risk factors and predictors

Background

The concept of high-impact chronic pain (HICP) has been proposed for patients with chronic pain who have significant limitations in work, social life, and personal care. Recognition of HICP and being able to distinguish patients with HICP from other chronic pain patients who do not have life interference allows the necessary measures to be taken in order to restore the physical and emotional functioning of the affected persons. The aim was to reveal the risk factors and predictors associated with HICP.

Methods

Patients with chronic pain without life interference (grade 1 and 2) and patients with HICP were compared. Significant data were evaluated with regression analysis to reveal the associated risk factors. Receiving operating characteristic (ROC) analysis was used to evaluate predictors and present cutoff scores.

Results

One thousand and six patients completed the study. From pain related cognitive processes, fear of pain (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.87-0.98; P = 0.007) and helplessness (OR, 1.06; 95% CI, 1.01-1.12; P = 0.018) were found to be risk factors associated with HICP. Predictors of HICP were evaluated by ROC analysis. The highest discrimination value was found for pain intensity (cut-off score > 6.5; 83.8% sensitive; 68.7% specific; area under the curve = 0.823; P < 0.001).

Conclusions

This is the first study in our geography to evaluate HICP with measurement tools that evaluate all dimensions of pain. Moreover, it is the first study in the literature to evaluate predictors and cut-off scores using ROC analysis for HICP.

Chronic pain and COVID-19 hospitalisation and mortality: a UK Biobank cohort study

ABSTRACT

The risk of COVID-19 in those with chronic pain is unknown. We investigated whether self-reported chronic pain was associated with COVID-19 hospitalisation or mortality. UK Biobank recruited 502,624 participants aged 37 to 73 years between 2006 and 2010. Baseline exposure data, including chronic pain (>3 months, in at least 1 of 7 prespecified body sites) and chronic widespread pain (>3 months, all over body), were linked to COVID-19 hospitalisations or mortality. Univariable or multivariable Poisson regression analyses were performed on the association between chronic pain and COVID-19 hospitalisation and Cox regression analyses of the associations with COVID-19 mortality. Multivariable analyses adjusted incrementally for sociodemographic confounders, then lifestyle risk factors, and finally long-term condition count. Of 441,403 UK Biobank participants with complete data, 3180 (0.7%) were hospitalised for COVID-19 and 1040 (0.2%) died from COVID-19. Chronic pain was associated with hospital admission for COVID-19 even after adjustment for all covariates (incidence rate ratio 1.16; 95% confidence interval [CI] 1.08-1.24; P < 0.001), as was chronic widespread pain (incidence rate ratio 1.33; 95% CI 1.06-1.66; P = 0.012). There was clear evidence of a dose-response relationship with number of pain sites (fully adjusted global P -value < 0.001). After adjustment for all covariates, there was no association between chronic pain (HR 1.01; 95% CI 0.89-1.15; P = 0.834) but attenuated association with chronic widespread pain (HR 1.50, 95% CI 1.04-2.16, P -value = 0.032) and COVID-19 mortality. Chronic pain is associated with higher risk of hospitalisation for COVID-19, but the association with mortality is unclear. Future research is required to investigate these findings further and determine whether pain is associated with long COVID.

Lean Mass is Associated with, but Does Not Mediate Sex Differences in Pressure Pain Sensitivity in Healthy Adults

Background

Sex differences exist in pain sensitivity, however, the underlying mechanism(s) that explain these differences are not fully understood. Pain sensitivity has been shown to be influenced by body mass index, but limited data exist on the role of body composition on pain sensitivity. The purpose was to examine the influence of body composition on pain sensitivity in males and females.

Methods

This cross-sectional study design used pressure pain thresholds (PPT) of 87 participants (45 female) who were assessed in the vastus lateralis (leg PPT) and brachioradialis (arm PPT) using a pressure algometer. Fat and lean tissue were assessed via dual-energy X-ray absorptiometry (DXA). A two group by two limb, repeated measured ANOVA was used to assess differences between limbs and sex. Spearman correlations and hierarchical regression analyses were employed to determine the association between body composition and PPT.

Results

Males had higher PPTs then females (P<0.05) and had higher DXA assessed lean and lower levels fat mass (P<0.05). Total body and limb specific lean mass was associated with PPTs (r≥0.34; P<0.05). Hierarchical regression analysis revealed lean mass was a significant predictor of 8% of the variance in arm PPT (P<0.006) and 18% of the variance in leg PPT (P<0.001). However, lean mass was not found to statistically mediate the observed sex differences in PPT.

Conclusion

This finding suggests lean mass may play a previously unknown role in sex differences in pressure pain sensitivity. Future studies are needed to confirm this finding and a larger sample size is likely required to have sufficient power to perform the mediation analysis.

Body Composition does not influence Conditioned Pain Modulation and Exercise Induced Hyperalgesia in Healthy Males and Females

BACKGROUND

Obese individuals report a higher susceptibility to chronic pain. Females are more likely to have chronic pain and excess adipose tissue. Chronic pain is associated with dysfunctional pain modulatory mechanisms. Body composition differences may be associated with pain modulation differences in males and females. The purpose of this study was to investigate body composition (lean vs fat mass) differences and pain modulatory functioning in healthy males and females.

METHODS

Pressure pain thresholds (PPT) of 96 participants (47M; 49F) were assessed in both arms and legs before and after a double footed ice bath (2°C) for 1min and an isometric knee extension, time to failure task. The difference between post and pre measures was defined conditioned pain modulatory (CPM) response (ice bath) and exercise induced hypoalgesia (EIH) response. Whole body and site-specific fat and lean tissue were assessed via DXA scan.

RESULTS

Sex differences were found in whole body lean mass (61.5±6.7kg vs 41.2±5.4kg; P<0.001) but not fat mass amount (17.2±10.5kg vs 21.0±9.7kg; P=0.068). No effect of sex was found between limb CPM (P=0.237) and limb EIH (P=0.512). When controlling for lean mass there was no significant effect of sex on CPM (P=0.732) or EIH (P=0.474) response. Similar findings were found for fat mass.

CONCLUSION

The lack of difference suggests that males and females have similar modulatory functioning. It appears that in healthy adults free from chronic pain, neither fat mass nor lean mass has an influence on endogenous pain modulatory function.

Serratus Anterior Block for Long-Term Post-Thoracoscopy Pain Management

Purpose

Neuropathic, chronic pain is a common and severe complication following thoracic surgery, known as post-thoracotomy pain syndrome (PTPS). Here we evaluated the efficacy of an ultrasound-guided serratus anterior plane block (SAPB) on pain control compared to traditional pain management with intravenous opioids and nonsteroidal anti-inflammatory drugs (NSAIDs) six months after thoracic surgery.

Patients and Methods

In this retrospective observational study, we analyzed data from a questionnaire survey. We interviewed all patients who underwent elective video-assisted thoracoscopy surgery (VATS) at Soroka University Medical Center between December 2016 and January 2018. The responses of ninety-one patients were included.

Results

Participants reported PTPS in both groups, 43% of patients in the SAPB group and 57% of patients in the standard group, which failed to reach significance. However, we demonstrated that the percentage of pain occurrence trended lower in the SAPB group. There was significantly less burning/stitching or shooting, shocking, pressure-like, and aching pain in SAPB patients compared to the standard protocol group. Patients in the SAPB group had significantly less pain located in the upper and lower posterior thorax anatomical regions compared to the standard protocol group. Moreover, we found a significant difference in occurrence of PTPS depending on the type of thoracic surgery. From both study groups, 69% of patients who underwent lobectomy reported pain, compared with 41.9% of those in the segmental (wedge resection) procedure, and 42.1% of patients in other procedures.

Conclusion

While the present study did not demonstrate a statistically significant reduction of PTPS after SAPB concerning postoperative pain control, there was a trend of a decrease. We also found significance in the type of pain and location of pain after thoracic surgery between the two groups, as well as a significant difference between pain occurrence in types of thoracic surgeries from both groups.

Mirogabalin as a Novel Gabapentinoid for the Treatment of Chronic Pain Conditions: An Analysis of Current Evidence

: Neuropathic pain is a challenge for physicians to treat and often requires a multimodal approach with both pharmacologic and lifestyle interventions. Mirogabalin, a potent, selective ligand of the α2δ-1 and α2δ-2 subunits of voltage-gated calcium channels (VGCCs), provides analgesia by inhibiting neurotransmitter release at the presynaptic end of the neuron. Mirogabalin offers more sustained analgesia than its gabapentinoid counterparts in addition to a wider safety margin for adverse events. Recent clinical trials of mirogabalin have demonstrated both efficacy and tolerability of the drug for the treatment of diabetic peripheral neuropathic pain and postherpetic neuralgia, leading to its approval in Japan. While still not yet FDA approved, mirogabalin is still in its infancy and offers potential into the treatment of neuropathic pain and its associated comorbidities.

The relationships among self-efficacy, social support, and self-care behavior in the elderly patients with chronic pain (a STROBE-compliant article)

The relationships among the self-efficacy, social support and self-care behavior in the elderly patients with chronic pain has not been reported. Therefore, we explored the relationships among self-efficacy, social support and self-care behavior in the elderly patients with chronic pain.General data questionnaire, self-efficacy scale, social support scale and self-care behavior scale were performed in 1032 elderly patients with chronic pain from Shenyang city between February and December 2017. The relationships among self-efficacy, social support and self-care behavior, and self-efficacy as a mediator between the social support and self-care behavior were analyzed by Pearson correlation analysis and Bootstrap method.In these elderly patients with chronic pain, the total scores of the self-efficacy, social support and self-care behavior were 35.59 ± 12.38, 65.64 ± 19.68 and 50.52 ± 15.26, respectively. The self-efficacy was positively correlated with the self-care behavior (r = 0.414, P < .001), the self-efficacy was positively correlated with the social support (r = 0.293, P < .001) and the social support was positively correlated with the self-care behavior (r = 0.322, P < .001). The mediating effect of self-efficacy was 0.121 which accounted for 27.31% of the total effects.The self-efficacy plays a mediating effect between social support and self-care behavior in the elderly patients with chronic pain.

The Association of Kinesiophobia and Pain Catastrophizing with Pain-Related Disability and Pain Intensity in Obesity and Chronic Lower-Back Pain

Individuals affected by chronic lower-back pain and obesity have an increased risk of long-lasting disability. In this study, we aimed to explore the contribution of kinesiophobia and pain catastrophizing in explaining pain intensity and pain-related disability in chronic lower-back pain associated to obesity. A cross-sectional study on 106 participants with obesity and chronic lower-back pain was performed. We assessed pain intensity, pain disability, pain catastrophizing, and kinesiophobia levels through self-reporting questionnaire. Hierarchical regressions were performed to assess the role of pain catastrophizing and kinesiophobia on pain intensity and pain disability. According to the results, kinesiophobia, but not pain catastrophing, significantly explained both pain intensity and pain-related disability. Kinesiophobia might play a significant role in enhancing pain-related disability and the pain intensity in individuals with chronic lower-back pain and obesity. We encourage future studies in which beliefs and cognition towards pain might be a therapeutic target in interdisciplinary pain management interventions.

The Efficacy of Sphenopalatine Ganglion Block and Radiofrequency Denervation in the Treatment of Cluster Headache: A Case Series

Background

Cluster headache is a variant of primary neurovascular headaches. some patients with cluster headache are not responsive to medical treatment and may benefit from interventional modalities, including sphenopalatine ganglion block and denervation.

Objectives

Our purpose was to evaluate the efficacy of sphenopalatine ganglion block/denervation in the treatment of cluster headache.

Methods

In this study, we performed the sphenopalatine ganglion block for patients with cluster headaches, intractable to medical therapy, who were referred to our pain clinic between 2014 and 2018. We registered the following information for all patients: demographic data, pain relief, and pain intensity. First, we conducted a prognostic C-arm-guided sphenopalatine ganglion block. If there was at least 50% pain relief within the first 5 h, then we denervated the ganglion by radiofrequency ablation. The main outcome of the study (dependent variable) was pain relief. We followed the patients for 6 months.

Results

Among 23 enrolled patients, 19 consented to interventional treatment. Fifteen out of 19 patients (79%) had an acceptable response to the prognostic block. Ultimately, 11 patients underwent ganglion denervation, and 4 patients did not consent for ganglion ablation. Pain relief at intervals of 48 h, and 1, 3, and 6 months after ganglion denervation was 77, 59, 50, and 31 percent, respectively.

Conclusions

Sphenopalatine ganglion conventional radiofrequency denervation can effectively decrease the pain intensity of the patients with cluster headache for at least several months.

The Influence of Chronic Pain on Number Sense and Numeric Rating Scale: A prospective Cohort Study

Background

Several studies have demonstrated an association between chronic pain and impairment of cognitive capabilities. Since the number sense is one of the cognitive ability involved in the evaluation of pain intensity using some pain measurement tools, impairment of number sense may impact pain assessment. Therefore, the validity of number-based pain assessment tools should be re-evaluated.

Objectives

This study aimed to determine whether number sense is altered in chronic and acute pain patients compared to healthy subjects.

Methods

Overall, 150 participants were recruited and divided into the three groups of controls, chronic and acute pain patients. Pain intensity was evaluated using numeric and verbal rating scales as pain assessment tools. Number sense was assessed using number naming, number marking, and line bisection tasks. Deviation from correct answers was measured for each task.

Results

Patients with chronic pain (migraine headache) had higher pain intensity scores than acute pain subjects. Chronic pain patients showed significant deviation from the expected responses compared to controls in the line bisection task.

Conclusions

Chronic pain patients may have impaired number sense and may differently use number-based pain assessment tools in comparison with healthy individuals.