Lessons for Better Pain Management in the Future: Learning from the Past

3,3-Dibromoflavanone, a synthetic flavonoid derivative for pain management with antidepressant-like effects and fewer side effects than those of morphine in mice

In the pursuit of new lead compounds with fewer side effects than opioids, the novel synthetic phytochemical core, 3,3-dibromoflavanone (3,3-DBF), has emerged as a promising candidate for pain management. Acute assays demonstrated dose-dependent central and peripheral antinociceptive activity of 3,3-DBF through the μ-opioid receptor. This study aimed to explore repeated administration effects of 3,3-DBF in mice and compare them with morphine. Mice were treated with 3,3-DBF (30 mg/kg), morphine (6 mg/kg), or vehicle for 10 days, alongside single-treatment groups. Unlike morphine, 3,3-DBF demonstrated antinociceptive effects in the hot plate test without inducing tolerance. Locomotor activity and motor coordination tests (evaluated through the inverted screen and rotarod tests) revealed no significant differences between the 3,3-DBF-treated and control groups. The gastrointestinal transit assay indicated that 3,3-DBF did not induce constipation, in contrast to morphine. Furthermore, withdrawal signs assessed with the Gellert-Holtzman scale were not comparable to morphine. Additionally, 3,3-DBF exhibited antidepressant-like activity, reducing immobility time in the forced swimming and tail suspension tests, akin to imipramine. In summary, 3,3-DBF demonstrated antinociceptive effects without inducing tolerance or dependence and exhibited antidepressant properties. These findings highlight the potential of 3,3-DBF as a promising therapeutic agent for pain management and its comorbidities, offering advantages over morphine by minimizing side effects.

Genetically Regulated Gene Expression in the Brain Associated With Chronic Pain: Relationships With Clinical Traits and Potential for Drug Repurposing

BACKGROUND

Chronic pain is a common, poorly understood condition. Genetic studies including genome-wide association studies have identified many relevant variants, which have yet to be translated into full understanding of chronic pain. Transcriptome-wide association studies using transcriptomic imputation methods such as S-PrediXcan can help bridge this genotype-phenotype gap.

METHODS

We carried out transcriptomic imputation using S-PrediXcan to identify genetically regulated gene expression associated with multisite chronic pain in 13 brain tissues and whole blood. Then, we imputed genetically regulated gene expression for over 31,000 Mount Sinai BioMe participants and performed a phenome-wide association study to investigate clinical relationships in chronic pain-associated gene expression changes.

RESULTS

We identified 95 experiment-wide significant gene-tissue associations (p < 7.97 × 10-7), including 36 unique genes and an additional 134 gene-tissue associations reaching within-tissue significance, including 53 additional unique genes. Of the 89 unique genes in total, 59 were novel for multisite chronic pain and 18 are established drug targets. Chronic pain genetically regulated gene expression for 10 unique genes was significantly associated with cardiac dysrhythmia, metabolic syndrome, disc disorders/dorsopathies, joint/ligament sprain, anemias, and neurologic disorder phecodes. Phenome-wide association study analyses adjusting for mean pain score showed that associations were not driven by mean pain score.

CONCLUSIONS

We carried out the largest transcriptomic imputation study of any chronic pain trait to date. Results highlight potential causal genes in chronic pain development and tissue and direction of effect. Several gene results were also drug targets. Phenome-wide association study results showed significant associations for phecodes including cardiac dysrhythmia and metabolic syndrome, thereby indicating potential shared mechanisms.

Clinical characteristics and long-term outcomes following pancreatic injury - An international multicenter cohort study

Background

Trauma to the pancreas is rare but associated with significant morbidity. Currently available management guidelines are based on low-quality evidence and data on long-term outcomes is lacking. This study aimed to evaluate clinical characteristics and patient-reported long-term outcomes for pancreatic injury.

Methods

A retrospective cohort study evaluating treatment for pancreatic injury in 11 centers across 5 European nations over >10 years was performed. Data relating to pancreatic injury and treatment were collected from hospital records. Patients reported quality of life (QoL), changes to employment and new or ongoing therapy due to index injury.

Results

In all, 165 patients were included. The majority were male (70.9%), median age was 27 years (range: 6-93) and mechanism of injury predominantly blunt (87.9%). A quarter of cases were treated conservatively; higher injury severity score (ISS) and American Association for the Surgery of Trauma (AAST) pancreatic injury scores increased the likelihood for surgical, endoscopic and/or radiologic intervention. Isolated, blunt pancreatic injury was associated with younger age and pancreatic duct involvement; this cohort appeared to benefit from non-operative management. In the long term (median follow-up 93; range 8-214 months), exocrine and endocrine pancreatic insufficiency were reported by 9.3% of respondents. Long-term analgesic use also affected 9.3% of respondents, with many reported quality of life problems (QoL) potentially attributable to side-effects of opiate therapy. Overall, impaired QoL correlated with higher ISS scores, surgical therapy and opioid analgesia on discharge.

Conclusions

Pancreatic trauma is rare but can lead to substantial short- and long-term morbidity. Near complete recovery of QoL indicators and pancreatic function can occur despite significant injury, especially in isolated, blunt pancreatic injury managed conservatively and when early weaning off opiate analgesia is achieved.

A Systematic Review and Meta-analysis of the Effectiveness of Radiofrequency Neurotomy in Managing Chronic Neck Pain

Background

Extensive research into potential sources of neck pain and referred pain into the upper extremities and head has shown that the cervical facet joints can be a potential pain source confirmed by precision, diagnostic blocks.

Study Design

Systematic review and meta-analysis utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist, quality assessment of the included studies, conventional and single-arm meta-analysis, and best evidence synthesis.

Objective

The objective of this systematic review and meta-analysis is to evaluate the effectiveness of radiofrequency neurotomy as a therapeutic cervical facet joint intervention in managing chronic neck pain.

Methods

Available literature was included. Methodologic quality assessment of studies was performed from 1996 to September 2021. The level of evidence of effectiveness was determined.

Results

Based on the qualitative and quantitative analysis with single-arm meta-analysis and Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system of appraisal, with inclusion of one randomized controlled trial (RCT) of 12 patients in the treatment group and eight positive observational studies with inclusion of 589 patients showing positive outcomes with moderate to high clinical applicability, the evidence is level II in managing neck pain with cervical radiofrequency neurotomy. The evidence for managing cervicogenic headache was level III to IV with qualitative analysis and single-arm meta-analysis and GRADE system of appraisal, with the inclusion of 15 patients in the treatment group in a positive RCT and 134 patients in observational studies. An overwhelming majority of the studies produced multiple lesions.

Limitations

There was a paucity of literature and heterogeneity among the available studies.

Conclusion

This systematic review and meta-analysis shows level II evidence with radiofrequency neurotomy on a long-term basis in managing chronic neck pain with level III to IV evidence in managing cervicogenic headaches.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40122-022-00455-0.

"It feels like an endless fight": a qualitative study exploring healthcare utilization of persons with rheumatic conditions waiting for pain clinic admission

Background

Individuals living with a rheumatic pain condition can face delays in accessing pain clinics, which prevents them from receiving timely treatment. Little is known regarding their specific healthcare utilization in order to alleviate pain while waiting to obtain services in pain clinics. Hence, the aim of this study was to explore the perceptions and experiences of persons living with rheumatic conditions regarding healthcare utilization while waiting to access a pain clinic.

Methods

In this qualitative descriptive study, semi-structured interviews were conducted with adults living with a painful rheumatic condition that reported either being waiting for admission in a pain clinic, having been referred but then denied pain clinic services, or having received services during the previous six months, in the province of Quebec, Canada. The interviews were transcribed verbatim, and an inductive thematic analysis was performed.

Results

Twenty-six individuals were interviewed (22 women and 4 men; mean age 54 ± 10 years). Three themes were identified: 1) lacking guidance in identifying solutions to their complex and multidimensional needs, 2) struggling to obtain and maintain services due to systemic access barriers, and 3) displaying resilience through a search for accessible and sustainable self-management strategies.

Conclusions

The current approaches and structures of health services fail to adequately answer the service needs of individuals experiencing painful rheumatic conditions. Important shifts are required in pain education, in increasing access to multidisciplinary approaches at the primary care level and in breaking down barriers individuals with chronic pain face to receive appropriate and timely care.

Study protocol for a phase II, double-blind, randomised controlled trial of cannabidiol (CBD) compared with placebo for reduction of brain neuroinflammation in adults with chronic low back pain

INTRODUCTION

Chronic pain is a debilitating medical problem that is difficult to treat. Neuroinflammatory pathways have emerged as a potential therapeutic target, as preclinical studies have demonstrated that glial cells and neuroglial interactions play a role in the establishment and maintenance of pain. Recently, we used positron emission tomography (PET) to demonstrate increased levels of 18 kDa translocator protein (TSPO) binding, a marker of glial activation, in patients with chronic low back pain (cLBP). Cannabidiol (CBD) is a glial inhibitor in animal models, but studies have not assessed whether CBD reduces neuroinflammation in humans. The principal aim of this trial is to evaluate whether CBD, compared with placebo, affects neuroinflammation, as measured by TSPO levels.

METHODS AND ANALYSIS

This is a double-blind, randomised, placebo-controlled, phase II clinical trial. Eighty adults (aged 18-75) with cLBP for >6 months will be randomised to either an FDA-approved CBD medication (Epidiolex) or matching placebo for 4 weeks using a dose-escalation design. All participants will undergo integrated PET/MRI at baseline and after 4 weeks of treatment to evaluate neuroinflammation using [¹¹C]PBR28, a second-generation radioligand for TSPO. Our primary hypothesis is that participants randomised to CBD will demonstrate larger reductions in thalamic [¹¹C]PBR28 signal compared with those receiving placebo. We will also assess the effect of CBD on (1) [¹¹C]PBR28 signal from limbic regions, which our prior work has linked to depressive symptoms and (2) striatal activation in response to a reward task. Additionally, we will evaluate self-report measures of cLBP intensity and bothersomeness, depression and quality of life at baseline and 4 weeks.

ETHICS AND DISSEMINATION

This protocol is approved by the Massachusetts General Brigham Human Research Committee (protocol number: 2021P002617) and FDA (IND number: 143861) and registered with ClinicalTrials.gov. Results will be published in peer-reviewed journals and presented at conferences.

TRIAL REGISTRATION NUMBER

NCT05066308; ClinicalTrials.gov.

Diagnostic and Predictive Capacity of the Spanish Versions of the Opioid Risk Tool and the Screener and Opioid Assessment for Patients with Pain-Revised: A Preliminary Investigation in a Sample of People with Noncancer Chronic Pain

INTRODUCTION

Accurate assessment of the risk of opioid abuse and misuse in people with noncancer chronic pain is crucial for their prevention. This study aimed to provide preliminary evidence of the diagnostic and predictive capacity of the Spanish versions of the Opioid Risk Tool (ORT) and the Screener and Opioid Assessment for Patients with Pain-Revised (SOAPP-R).

METHODS

We used the Current Opioid Misuse Measure (COMM) as criterion measure to assess the capacity of each tool to identify patients misusing opioids at the time of the assessment. Eighteen months later, we used the COMM and the Drug Abuse Screening Test-10 (DAST-10) to assess their predictive capacity. In total, 147 people with noncancer chronic pain participated in the diagnostic study, and 42 in the predictive study.

RESULTS

Receiver operating curve analysis showed that the SOAPP-R had an excellent capacity to identify participants who were misusing opioids at the time of assessment (area under the curve [AUC] = 0.827). The diagnostic capacity of the ORT was close to acceptable (AUC = 0.649-0.669), whereas its predictive capacity was poor (AUC = 0.522-0.554). The predictive capacity of the SOAPP-R was close to acceptable regarding misuse (AUC = 0.672) and poor regarding abuse (AUC = 0.423).

CONCLUSION

In the setting of Spanish-speaking communities, clinicians should be cautious when using these instruments to make decisions on opioid administration. Further research is needed on the diagnostic and predictive capacity of the Spanish versions of both instruments.

Inhibiting the Musculoskeletal Pathological Processes in Post-knee Replacement Surgery With Osteopathic Manipulative Treatment: A Systematic Review

Total knee arthroplasty (TKA) is a very common surgical treatment approach for severe osteoarthritis. Complications of TKA include loss of range of motion and prolonged analgesic requirement for pain control. Osteopathic manipulative techniques (OMT) have been utilized to address localized muscular stiffness to improve range of motion; however, limited studies directly correlate OMT and TKA recovery. This review highlights the therapeutic benefits OMT can have in the postoperative management of arthroplasty with respect to range of motion, edema, pain perception, and ability to perform activities of daily living. This review revealed the use of OMT would positively influence range of motion by manipulation of localized musculature and can result in decreased demand for analgesics. This can, in turn, shorten hospital stay and return the ability of patients to perform activities of daily living earlier than without OMT. Increased research is needed to strengthen these findings on the benefits of OMT in the postoperative management of arthroplasty.

Efficacy of Radiofrequency Neurotomy in Chronic Low Back Pain: A Systematic Review and Meta-Analysis

Purpose

The objective of the systematic review and meta-analysis is to evaluate the efficacy of radiofrequency neurotomy as a therapeutic lumbar facet joint intervention.

Patients and Methods

Utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist, a systematic review and meta-analysis was performed. A comprehensive literature search of multiple data sources from 1966 to September 2020 including manual searches of bibliography of known review articles was performed. The inclusion criteria were based on the selection of patients with chronic low back pain with diagnosis confirmed based on controlled diagnostic blocks and with the publication of at least 6 months of results of appropriate outcome parameters. Quality assessment of the trials was performed with Cochrane review criteria and interventional pain management techniques-quality appraisal of reliability and risk of bias assessment (IPM-QRB). The level of evidence of effectiveness is classified at five levels ranging from Level I to Level V. The primary outcome measure was a significant reduction in pain, eg, short term (up to 6 months) and long term (more than 6 months). The secondary outcome measure was an improvement in functional status.

Results

A total of 12 randomized controlled trials (RCTs) met the inclusion criteria for evaluating the efficacy of lumbar radiofrequency neurotomy. Radiofrequency neurotomy showed Level II evidence for efficacy for both the short term and long term.

Conclusion

This systematic review of the assessment of the efficacy of radiofrequency neurotomy in managing chronic low back pain was based on the inclusion of 12 RCTs with a diagnostic block and at least 6 months of follow-up results that showed Level II evidence for both short-term and long-term improvement.

Using Telerehabilitation to Deliver a Home Exercise Program to Youth With Arthrogryposis: Single Cohort Pilot Study

BACKGROUND

Arthrogryposis multiplex congenita (AMC) is characterized by joint contractures and muscle weakness, which limit daily activities. Youths with AMC require frequent physical therapeutic follow-ups to limit the recurrence of contractures and maintain range of motion (ROM) and muscle strength; however, access to specialized care may be limited because of geographical distance. Telerehabilitation can offer a potential solution for delivering frequent follow-ups for youth with AMC, but research on the use of telerehabilitation in children with musculoskeletal disorders is scarce.

OBJECTIVE

The study aims to evaluate the feasibility of delivering a home exercise program (HEP) by using telerehabilitation for youth with AMC. We also aim to explore the effectiveness of the HEP as a secondary aim.

METHODS

Youths aged between 8 and 21 years with AMC were recruited at the Shriners Hospitals for Children-Canada. The participants completed baseline and post-HEP questionnaires (the Physical Activity Questionnaire for Adolescents, Pediatrics Outcomes Data Collection Instrument, and Adolescent and Pediatric Pain Tool), and clinicians assessed their active ROM using a virtual goniometer. Clinicians used the Goal Attainment Scale with the participants to identify individualized goals to develop a 12-week HEP and assess the achievement of these goals. Follow-ups were conducted every 3 weeks to adjust the HEP. Data on withdrawal rates and compliance to the HEP and follow-ups were collected to assess the feasibility of this approach. The interrater reliability of using a virtual goniometer was assessed using the intraclass correlation coefficient and associated 95% CI. Nonparametric tests were used to evaluate feasibility and explore the effectiveness of the HEP.

RESULTS

Of the 11 youths who were recruited, 7 (median age: 16.9 years) completed the HEP. Of the 47 appointments scheduled, 5 had to be rescheduled in ≤24 hours. The participants performed their HEP 2.04 times per week (95% CI 1.25-4.08) and reported good satisfaction with the approach. A general intraclass correlation coefficient of 0.985 (95% CI 0.980-0.989) was found for the web-based ROM measurement. Individualized goals were related to pain management; endurance in writing, standing, or walking; sports; and daily activities. In total, 12 of the 15 goals set with the participants were achieved. Statistically significant improvements were observed in the pain and comfort domain of the Pediatrics Outcomes Data Collection Instrument (preintervention: median 71; 95% CI 34-100; postintervention: median 85; 95% CI 49-100; P=.08) and Physical Activity Questionnaire for Adolescents (preintervention: median 1.62; 95% CI 1.00-2.82; postintervention: median 2.32; 95% CI 1.00-3.45; P=.046).

CONCLUSIONS

The remote delivery of an HEP for youth with AMC is feasible. Promising results were found for the effectiveness of the HEP in helping youths with AMC to achieve their goals. The next step will be to assess the effectiveness of this exercise intervention in a randomized controlled trial.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/18688.

Advocating for Multimodal Pain Management and Reducing the Need for Opioids in the Acute and Chronic Pain Setting

The opioid epidemic skyrocketed around 2017 when many pharmaceutical companies guaranteed effective pain relief with nonaddictive properties of prescription opioids. However, this has proven to be inadequate because opioid misuse has increased in the United States. These catastrophic consequences led many providers to take on a different approach to pain management in the acute and chronic setting. In the last few years, a great deal of research has focused more on a multimodal pain management approach, in hopes to decrease the rate of opioid misuse and related overdoses and help assist in putting an end to this public health crisis.

COVID-19 and the Opioid Epidemic: Two Public Health Emergencies That Intersect With Chronic Pain

The COVID-19 pandemic has affected the entire world and catapulted the United States into one of the deepest recessions in history. While this pandemic rages, the opioid crisis worsens. During this period, the pandemic has resulted in the decimation of most conventional medical services, including those of chronic pain management, with the exception of virtual care and telehealth. Many chronic pain patients have been impacted in numerous ways, with increases in cardiovascular disease, mental health problems, cognitive dysfunction, and early death. The epidemic has also resulted in severe economic and physiological consequences for providers. Drug deaths in America, which fell for the first time in 25 years in 2018, rose to record numbers in 2019 and are continuing to climb, worsened by the coronavirus pandemic. The opioid epidemic was already resurfacing with a 5% increase in overall deaths from 2018; however, the preliminary data show that prescription opioid deaths continued to decline, while at the same time deaths due to fentanyl, methamphetamine, and cocaine climbed, with some reductions in heroin deaths. The health tracker data also showed that along with an almost 88% decline in elective surgeries, pain-related prescriptions declined 15.1%. Despite increases in telehealth, outpatient services declined and only began returning towards normal at an extremely slow pace, accompanied by reduced productivity and increased practice costs. This review, therefore, emphasizes the devastating consequences of concurrent epidemics on chronic pain management and the need to develop best practice efforts to preserve access to treatment for chronic pain.

A safety review of approved intrathecal analgesics for chronic pain management

Introduction: Intrathecal (IT) drug therapy is an effective treatment option for patients with chronic pain of malignant or nonmalignant origin, with an established safety profile and fewer adverse effects compared to oral or parenteral pain medications. Morphine (a μ-opioid receptor agonist) and ziconotide (a non-opioid calcium channel antagonist) are the only IT agents approved by the U.S. Food and Drug Administration for the treatment of chronic pain. Although both are considered first-line IT therapies, each drug has unique properties and considerations.Areas Covered: This review will evaluate the pivotal trials that established the use of morphine and ziconotide as first-line IT therapy for patients with chronic pain, as well as safety and efficacy data generated from various retrospective and prospective studies.Expert Opinion: Morphine and ziconotide are effective IT therapies for patients with chronic malignant or nonmalignant pain that is refractory to other interventions. IT ziconotide is recommended as a first-line therapy due to its efficacy and avoidance of many adverse effects commonly associated with opioids. The use of IT morphine is also considered first-line; however, the risks of respiratory depression, withdrawal with drug discontinuation or pump malfunction, and the development of tolerance require careful patient selection and management.

Association of nocebo hyperalgesia and basic somatosensory characteristics in a large cohort

Medical outcomes are strongly affected by placebo and nocebo effects. Prediction of who responds to such expectation effects has proven to be challenging. Most recent approaches to prediction have focused on placebo effects in the context of previous treatment experiences and expectancies, or personality traits. However, a recent model has suggested that basic somatosensory characteristics play an important role in expectation responses. Consequently, this study investigated not only the role of psychological variables, but also of basic somatosensory characteristics. In this study, 624 participants underwent a placebo and nocebo heat pain paradigm. Additionally, individual psychological and somatosensory characteristics were assessed. While no associations were identified for placebo responses, nocebo responses were associated with personality traits (e.g. neuroticism) and somatosensory characteristics (e.g. thermal pain threshold). Importantly, the associations between somatosensory characteristics and nocebo responses were among the strongest. This study shows that apart from personality traits, basic somatosensory characteristics play an important role in individual nocebo responses, in agreement with the novel idea that nocebo responses result from the integration of top-down expectation and bottom-up sensory information.

Feasibility of Imported Self-Management Program for Elderly People with Chronic Pain: A Single-Arm Confirmatory Trial

INTRODUCTION

Multidisciplinary pain management programs incorporating a cognitive-behavioral therapy (CBT) approach have been reported to be helpful for elderly people with chronic pain. However, it is unclear whether the same program for elderly people with chronic pain would translate to different cultures. This study investigated whether a multidisciplinary program based on that of Nicholas et al. (Pain 154(6):824-835, 2013) in Australia would be effective for elderly people with chronic pain in Japan.

METHODS

Twenty-seven community-dwelling elderly people with chronic pain were enrolled to confirm changes (effect size d = 0.5) in pain disability, which were previously reported by Nicholas et al. The multidisciplinary program consisted of eight sessions (2 sessions a week for 4 weeks). Pain disability was assessed using the Pain Disability Assessment Scale (PDAS) as the primary outcome at the baseline, the beginning and the end of the program, and the 1- and 3-month (final) follow-up. We also assessed the pain severity, catastrophizing, pain self-efficacy, and physical function with the Timed Up and Go test (TUG) and the two-step test as secondary outcomes.

RESULTS

PDAS, pain catastrophizing, and pain self-efficacy were significantly improved immediately after the program compared with baseline, and these effects were maintained at 3-month follow-up. The effect size (d) for the PDAS score was a medium size (0.54) from baseline to 3-month follow-up. Those who showed improvements in TUG immediately after the program tended to report improved psychometric measures at 3-month follow-up.

CONCLUSION

These results suggest that the Japanese multidisciplinary program has a similar effect on pain disability as that reported by Nicholas et al. This finding has important implications for the development of pain services in community-dwelling elderly Japanese.

A virtual experimenter does not increase placebo hypoalgesia when delivering an interactive expectancy manipulation

Lack of standardization and unblinding threaten the research of mechanisms involved in expectancy effects on pain. We evaluated a computer-controlled virtual experimenter (VEx) to avoid these issues. Fifty-four subjects underwent a baseline-retest heat pain protocol. Between sessions, they received an expectancy manipulation (placebo or no-treatment) delivered by VEx or text-only control condition. The VEx provided standardized "social" interaction with the subjects. Pain ratings and psychological state/trait measures were recorded. We found an interaction of expectancy and delivery on pain improvement following the intervention. In the text conditions, placebo was followed by lower pain, whereas in the VEx conditions, placebo and no-treatment were followed by a comparable pain decrease. Secondary analyses indicated that this interaction was mirrored by decreases of negative mood and anxiety. Furthermore, changes in continuous pain were moderated by expectation of pain relief. However, retrospective pain ratings show an effect of expectancy but not of delivery. We conclude that we successfully applied an automated protocol for inducing expectancy effects on pain. The effect of the VEx regardless of treatment may be due to interactions of attention allocation and locus of control. This points to the diversity of expectancy mechanisms, and has implications for research and computer-based treatment applications.