Faculty Bibliography

Chronic low back pain is a prevalent and sometimes debilitating condition. This case report describes a 69-year-old female presenting with axial spine pain. The pain was inadequately controlled by opioids as she was treated unsuccessfully with hydrocodone and remained to have the pain between 7/10 and 10/10. Peripheral neural stimulation (PNS) was trialed and then used to control her pain. PNS is a device-based treatment option that appears effective in a subset of patients. It has been effectively used to treat many different chronic pain syndromes. The patient responded well to the treatment, with her pain intensity going down to between 2/10 and 5/10 on the same scale. She was able to discontinue her use of opioids. PNS can be a safe and effective treatment in patients who have not responded well to pharmacologic analgesia.

BACKGROUND:Epidural steroid injections (ESI) are one of the most commonly performed pain procedures; however, there has been variation in techniques and approaches amongst pain physicians in the United States. The formation of a multidisciplinary working group was made with considerations to help guide ESI practice. OBJECTIVE:Pain medicine physicians in the United States were surveyed in order to provide an update on current practices for both transforaminal and interlaminar ESI. STUDY DESIGN AND SETTING/METHODS:This was a cross-sectional survey of pain medicine physicians in the United States. METHODS:This study was approved by the institutional review board of our institution. Based on the American Society of Interventional Pain Physicians membership database, an email list was generated, and a web-based survey was sent to interventional pain physicians at academic centers, private practices, government hospitals, and community settings across the United States. Cervical, lumbar, and caudal ESI sections were divided into questions regarding preferences for fluoroscopic views, injectates, and techniques. RESULTS:A total of 261 responses were analyzed. All but one used fluoroscopy for lumbar ESI. There were variations in methods to detect intravascular uptake, choice of injectate, and the use of particulate steroids for lumbar transforaminal epidural steroid injection (TFESI). LIMITATIONS/CONCLUSIONS:The response rate is a limitation, and thus the results may not be representative of all pain medicine physicians in the United States. CONCLUSIONS:Since the 2015 multidisciplinary pain workgroup recommendations were made for ESI, there appears to be a trend towards following these guidelines compared to prior surveys looking at ESI practices. However, our survey shows there continues to be variations in ESI practice that deviates from these guidelines.

INTRODUCTION/UNASSIGNED:Guidelines recommend a number of pharmacotherapeutic options used as monotherapy or in combination with others for treating the pain of trigeminal neuropathy. AREAS COVERED/UNASSIGNED:The authors examine the pharmacotherapeutic options for treating trigeminal neuralgia and supporting evidence in the literature. Guidelines reported the most effective treatment for trigeminal neuropathy, in particular trigeminal neuralgia, appears to be carbamazepine or oxcabazepine, but side effects can be treatment limiting. Lamotrigine and gabapentin are also recommended in guidance. In real-world clinical practice, baclofen, cannabinoids, eslicarbazepine, levetiracetam, brivaracetam, lidocaine, misoprostol, opioids, phenytoin, fosphenytoin, pimozide, sodium valproate, sumatriptan, tizanidine, tocainide, tricyclic antidepressants, and vixotrigine are sometimes used, either as monotherapy or in combination. The relatively small patient population has limited the number of large-scale studies and there is limited evidence on which to base prescribing choices. EXPERT OPINION/UNASSIGNED:While there is no optimal pharmacotherapy for treating trigeminal neuropathy, advancements in our understanding of the underlying mechanisms of this condition and drug development indicate promise for NaV inhibitors, despite the fact that not all patients respond to them and they may have potentially treatment-limiting side effects. Nevertheless, better understanding of NaV channels may be important avenues for future drug development for trigeminal neuropathy.

BACKGROUND:Multiple publications have shown the significant impact of the COVID-19 pandemic on US healthcare and increasing costs over the recent years in managing low back and neck pain as well as other musculoskeletal disorders. The COVID-19 pandemic has affected many modalities of treatments, including those related to chronic pain management, including both interventional techniques and opioids. While there have not been assessments of utilization of interventional techniques specific to the ongoing COVID-19 pandemic, previous analysis published with data from 2000 to 2018 demonstrated a decline in utilization of interventional techniques from 2009 to 2018 of 6.7%, with an annual decline of 0.8% per 100,000 fee-for-service (FFS) in the Medicare population. During that same time, the Medicare population has grown by 3% annually. OBJECTIVES:The objectives of this analysis include an evaluation of the impact of the COVID-19 pandemic, as well as an updated assessment of the utilization of interventional techniques in managing chronic pain in the Medicare population from 2010 to 2019, 2010 to 2020, and 2019 to 2020 in the FFS Medicare population of the United States. STUDY DESIGN:Utilization patterns and variables of interventional techniques with the impact of the COVID-19 pandemic in managing chronic pain were assessed from 2000 to 2020 in the FFS Medicare population of the United States. METHODS:The data for the analysis was obtained from the master database from the Centers for Medicare & Medicaid Services (CMS) physician/supplier procedure summary from 2000 to 2020. RESULTS:The results of the present investigation revealed an 18.7% decrease in utilization of all interventional techniques per 100,000 Medicare beneficiaries from 2019 to 2020, with a 19% decrease for epidural and adhesiolysis procedures, a 17.5% decrease for facet joint interventions and sacroiliac joint blocks, and a 25.4% decrease for disc procedures and other types of nerve blocks. The results differed from 2000 to 2010 with an annualized increase of 10.2% per 100,000 Medicare population compared to an annualized decrease of 0.4% from 2010 to 2019, and a 2.5% decrease from 2010 to 2020 for all interventional techniques. For epidural and adhesiolysis procedures decreases were more significant and annualized at 3.1% from 2010 to 2019, increasing the decline to 4.8% from 2010 to 2020. For facet joint interventions and sacroiliac joint blocks, the reversal of growth patterns was observed but maintained at an annualized rate increase of 2.1% from 2010 to 2019, which changed to a decrease of 0.01% from 2010 to 2020. Disc procedures and other types of nerve blocks showed similar patterns as epidurals with an 0.8% annualized reduction from 2010 to 2019, which was further reduced to 3.6% from 2010 to 2020 due to COVID-19. LIMITATIONS:Data for the COVID-19 pandemic impact were available only for 2019 and 2020 and only the FFS Medicare population was utilized; utilization patterns in Medicare Advantage Plans, which constitutes almost 40% of the Medicare enrollment in 2020 were not available. Moreover, this analysis shares the limitations present in all retrospective reviews of claims based datasets. CONCLUSION:The decline driven by the COVID-19 pandemic was 18.7% from 2019 to 2020. Overall decline in utilization in interventional techniques from 2010 to 2020 was 22.0% per 100,000 Medicare population, with an annual diminution of 2.5%, despite an increase in the population rate of 3.3% annualized (38.9% overall) and Medicare enrollees of 33.4% and 2.9% annually.

Introduction/UNASSIGNED:Given the opioid epidemic in the US, it is vital that clinicians who prescribe opioids for pain management to do so in an evidence-based manner, eg considering all pharmacologic and non-pharmacologic options, assessing risk of opioid use disorder prior to initiating opioids. Continuing education regarding the evidence-based prescribing of opioids is now required for US healthcare providers who prescribe opioids. A "blueprint" of the content to be included in continuing education programs was developed by the US Food and Drug Administration and updated in 2018. Methods/UNASSIGNED:To understand the baseline knowledge and confidence of healthcare professionals in prescribing opioids for pain management, we posed 27 unique knowledge-based questions and 1 confidence question to clinician participants before or during 2 continuing educational programs that were based respectively on the 2016 and 2018 FDA Risk Evaluation and Mitigation Strategy (REMS) educational blueprints for pain management. Results/UNASSIGNED:Overall, 5571 clinicians completed these programs, including 1925 physicians (1516 [79%] identifying as primary care), 1181 physician assistants, 737 advanced practice nurses, 719 nurses, and 479 pharmacists. Responses to pretest questions in both programs indicated profound and persistent gaps in knowledge, particularly in definitions and mechanisms of pain, general principles of pharmacologic analgesic therapy, and specific aspects of opioid analgesic therapy and addiction. Participants in both programs also expressed limited confidence in their abilities to incorporate patient engagement techniques into pain management or develop a treatment plan for a patient with chronic pain. Discussion/UNASSIGNED:These data support an ongoing need for comprehensive clinician-based education as outlined in the FDA REMS educational blueprint, especially given recent data of escalating overdose deaths during the COVID-19 pandemic.

Overprescribing of opioids after surgical procedures can increase the risk of addiction in patients, and under prescribing can lead to poor quality of care. In this study, we propose a machine learning-based predictive framework to identify the varying effects of factors that are related to the opioid prescription amount after orthopaedic surgery. To predict the prescription classes, we train multiple classifiers combined with random and SMOTE over-sampling and weight-balancing techniques to cope with the imbalance state of the dataset. Our results show that the gradient boosting machines (XGB) with SMOTE achieve the highest classification accuracy. Our proposed analytical framework can be employed to assist and therefore, enable the surgeons to determine the timely changing effects of these variables.

BACKGROUND:Chronic spinal pain is the most prevalent chronic disease with employment of multiple modes of interventional techniques including epidural interventions. Multiple randomized controlled trials (RCTs), observational studies, systematic reviews, and guidelines have been published. The recent review of the utilization patterns and expenditures show that there has been a decline in utilization of epidural injections with decrease in inflation adjusted costs from 2009 to 2018. The American Society of Interventional Pain Physicians (ASIPP) published guidelines for interventional techniques in 2013, and guidelines for facet joint interventions in 2020. Consequently, these guidelines have been prepared to update previously existing guidelines. OBJECTIVE:To provide evidence-based guidance in performing therapeutic epidural procedures, including caudal, interlaminar in lumbar, cervical, and thoracic spinal regions, transforaminal in lumbar spine, and percutaneous adhesiolysis in the lumbar spine. METHODS:The methodology utilized included the development of objective and key questions with utilization of trustworthy standards. The literature pertaining to all aspects of epidural interventions was viewed with best evidence synthesis of available literature and  recommendations were provided. RESULTS:In preparation of the guidelines, extensive literature review was performed. In addition to review of multiple manuscripts in reference to utilization, expenditures, anatomical and pathophysiological considerations, pharmacological and harmful effects of drugs and procedures, for evidence synthesis we have included 47 systematic reviews and 43 RCTs covering all epidural interventions to meet the objectives.The evidence recommendations are as follows: Disc herniation: Based on relevant, high-quality fluoroscopically guided epidural injections, with or without steroids, and results of previous systematic reviews, the evidence is Level I for caudal epidural injections, lumbar interlaminar epidural injections, lumbar transforaminal epidural injections, and cervical interlaminar epidural injections with strong recommendation for long-term effectiveness.The evidence for percutaneous adhesiolysis in managing disc herniation based on one high-quality, placebo-controlled RCT is Level II with moderate to strong recommendation for long-term improvement in patients nonresponsive to conservative management and fluoroscopically guided epidural injections. For thoracic disc herniation, based on one relevant, high-quality RCT of thoracic epidural with fluoroscopic guidance, with or without steroids, the evidence is Level II with moderate to strong recommendation for long-term effectiveness.Spinal stenosis: The evidence based on one high-quality RCT in each category the evidence is Level III to II for fluoroscopically guided caudal epidural injections with moderate to strong recommendation and Level II for fluoroscopically guided lumbar and cervical interlaminar epidural injections with moderate to strong recommendation for long-term effectiveness.The evidence for lumbar transforaminal epidural injections is Level IV to III with moderate recommendation with fluoroscopically guided lumbar transforaminal epidural injections for long-term improvement. The evidence for percutaneous adhesiolysis in lumbar stenosis based on relevant, moderate to high quality RCTs, observational studies, and systematic reviews is Level II with moderate to strong recommendation for long-term improvement after failure of conservative management and fluoroscopically guided epidural injections. Axial discogenic pain: The evidence for axial discogenic pain without facet joint pain or sacroiliac joint pain in the lumbar and cervical spine with fluoroscopically guided caudal, lumbar and cervical interlaminar epidural injections, based on one relevant high quality RCT in each category is Level II with moderate to strong recommendation for long-term improvement, with or without steroids. Post-surgery syndrome: The evidence for lumbar and cervical post-surgery syndrome based on one relevant, high-quality RCT with fluoroscopic guidance for caudal and cervical interlaminar epidural injections, with or without steroids, is Level II with moderate to strong recommendation for long-term improvement. For percutaneous adhesiolysis, based on multiple moderate to high-quality RCTs and systematic reviews, the evidence is Level I with strong recommendation for long-term improvement after failure of conservative management and fluoroscopically guided epidural injections. LIMITATIONS/CONCLUSIONS:The limitations of these guidelines include a continued paucity of high-quality studies for some techniques and various conditions including spinal stenosis, post-surgery syndrome, and discogenic pain. CONCLUSIONS:These epidural intervention guidelines including percutaneous adhesiolysis were prepared with a comprehensive review of the literature with methodologic quality assessment and determination of level of evidence with strength of recommendations.

Chronic pain management during the coronavirus disease 2019 (COVID-19) pandemic is a challenging process, especially with growing evidence that COVID-19 infection is associated with myalgias, referred pain, and widespread hyperalgesia. In light of the limited data available for COVID-19-related impact on chronic pain patients, this review explores the changes in the healthcare delivery system due to social distancing and safety precautions to provide the appropriate management of chronic pain patients during the COVID-19 pandemic. Understanding both the general problems facing chronic pain patients as well as specific problems in the COVID-19 era including deconditioning, increased mental health concerns, financial burdens, and potential for medication-induced immune-suppression is vital in the appropriate management of patients. Telemedicine, the practice of caring for patients remotely when the provider and patient are not physically present with each other, is becoming increasingly used and recognized as a valuable tool to both health care providers and patients. This paper concentrates on the proper utilization of the available resources to help patients with the most severe conditions as well as the most vulnerable group. COVID-19 may be associated with a profound effect on both the health care system and patients with chronic pain. As a result, delaying, or stopping, treatment for chronic pain patients will have negative consequences, and strong pain evaluations must be administered to triage patients appropriately. Recent recommendations for the safe use of non-opioid analgesics, opioid analgesics, and interventional pain management procedures are vital to know and understand specifically during the pandemic era. Further researches are needed to identify the advance planning and rapid responses to reduce the impact of the pandemic.

Purpose Painful neuropathy or peripheral neuropathic pain (PNP) is a common neurological condition estimated to affect ~7-8% of the general population in Europe. Managing patients with PNP is challenging; it often becomes chronic and can have a significant impact on quality of life. According to the revised International Association for the Study of Pain (IASP) recommendations for ICD11, PNP is considered to be a distinct chronic pain condition (Scholz et al., 2019)1. Postherpetic neuralgia (PHN) following shingles infection, has specifically been named as one of the PNP conditions. High concentration 8% capsaicin patch (HCCP) is commonly recommended as a second line therapy for PHN. HCCP is indicated for the treatment of peripheral neuropathic pain (PNP) in the EU and for the treatment of neuropathic pain associated with postherpetic neuralgia (PHN) and for neuropathic pain associated with diabetic peripheral neuropathy (DPN) of the feet in the US. Capsaicin is a highly selective, potent and highaffinity exogenous agonist for the transient receptor potential cation channel subfamily V member 1 (TRPV1) receptors which, through a combination of activities, defunctionalizes nociceptor fibers and reduces cutaneous hypersensitivity. As a result, capsaicin is an attractive peripherally acting treatment to control localized pain, hyperalgesia, or allodynia (Anand and Bley, 2011)2. The HCCP delivers the drug effectively and directly to the skin while limiting the risk of systemic effects and drug interactions. Whilst controlled trials have demonstrated the safety and effectiveness of capsaicin patches, the STRIDE study was designed to investigate the long-term safety of repeated patch administration in patients with non-diabetic neuropathic pain (Galvez et al., 2017)3. The present analysis considers the effect on treatment outcomes among a subgroup of patients with PHN included in the STRIDE study. Methods The STRIDE study was an open-label, multicenter, 52-week observational trial conducted in Europe. A diagnosis of PHNwas based on pain persisting since shingles vesicle crusting, for a minimum of 3 months. Prior treatment with capsaicin patches and a history of diabetes were among the exclusion criteria. Patients received up to 6 capsaicin 640 g/cm2 (8% weight for weight) HCCP treatments at 9-to 12-week intervals. At each application visit, a maximum of 4 patches equivalent to an area of up to 1120 cm2 were applied for 60 minutes. HCCP retreatment was at the investigator's discretion and according to patient feedback. Long-term tolerability and safety were the primary objectives of the study. In addition, areas of spontaneous pain and allodynia were monitored, and various scales were used to assess pain, quality of life and overall treatment outcome at each retreatment assessment timepoint. Descriptive statistics (including means and standard deviations) are presented; missing observations were not imputed. Results Of the 107 PHN patients included in the study, 66 completed the trial. The reason for withdrawal was lack of efficacy (14.95%), adverse events in (4.67%) and other reasons (18.69%). HCCP was applied once in 22 patients, twice in 26, three times in 24 and >=4 times in 35. All but 1 patient used preapplication topical anesthesia during the study, and 79.4% used concomitant medications for neuropathic pain. 73% of patients experienced possible or probable drugrelated adverse events, mostly associated with transient application site reactions (57.9%). The maximum severity was mild or moderate in 57% of cases, and only 1 drug-related event required treatment discontinuation. The average daily pain score was reduced from a baseline value of 6.6 (SD, 1.46) to 5.0 (1.99) after 6 months and 4.6 (2.18) after 12 months. The overall change in mean daily pain intensity by the end of study was approximately -1.7. The proportion of responders (>=30% decrease from baseline on a Numerical Pain Rating Scale) progressively increased during the study, to 22.7% after 3 months, and 33.3% and 39.7% after 6 and 12 months, respectively. Over 50% of patients showed at least minimal improvement according to the assessment of their condition by the end of study. The area of allodynia/ hyperplasia and the extent of spontaneous pain (reported in most patients at baseline, mainly on the torso) decreased during the study by just over 20%. Conclusions HCCP repeat application over 12 months in patients with PHN was well tolerated, with mostly transient local adverse events directly linked to the site of application. Progressive and sustained reduction in pain intensity was achieved, as well as reductions in the area of allodynia and spontaneous pain. Overall, the findings from this study demonstrate that repeated HCCP application is a well-tolerated and effective long-term treatment option in patients with PHN

(1) Spinal Cord Microglial Phenotypic Changes Following Sciatic Nerve Crush in CD137LKO Mice / David Nicholas, Kinuyo Ohara, Ling Cao -- (2) Notalgia Paresthetica Successfully Treated with Cervical Epidural Injection and Occipital Nerve Block: A Case Report / Fabienne Saint-Preux, Justin Mendoza, Salvador Portugal