Case Series of Multicontact Peripheral Nerve Stimulation in the Transversus Abdominis Plane for Chronic Abdominal Wall Pain.

OBJECTIVES: Managing abdominal pain can be difficult. This is due to the nonspecific nature of the pain, the multiple etiologies, and the different mechanisms underlying this type of pain. Abdominal wall pain in particular poses its own challenges. Traditionally, chronic abdominal wall pain has been managed with nonopioid analgesics, and in severe cases, opioid therapy has been considered. For patients with chronic abdominal wall pain refractory to medication management, peripheral nerve blocks and spinal cord stimulation also have been trialed with some success. In this study, we present a case series in patients with chronic abdominal wall pain who were treated with a multicontact peripheral nerve stimulation (PNS) system in the transversus abdominis plane (TAP). MATERIALS AND METHODS: This was a single-center, retrospective case series. Data were included from adults with chronic abdominal wall pain whose symptoms were refractory to standard medical management and who underwent a multicontact PNS system placement in the TAP. RESULTS: Four patients met the inclusion criteria. All four patients underwent a multicontact PNS trial lead placement in the TAP. One patient reported no benefit from the trial. The remaining three patients underwent a permanent multicontact PNS system placement in the TAP. CONCLUSIONS: In patients with chronic abdominal wall pain whose symptoms are refractory to conservative medical management, PNS may be an alternative treatment option. As the use of PNS for chronic abdominal wall pain and other fascial planes continues to develop, additional research is necessary to determine optimal placements and specific stimulation parameters.

The Polyanalgesic Consensus Conference (PACC)®: Updates on Clinical Pharmacology and Comorbidity Management in Intrathecal Drug Delivery for Cancer Pain.

INTRODUCTION: The International Neuromodulation Society convened a multispecialty group of physicians based on expertise with international representation to establish evidence-based guidance on using intrathecal drug delivery in chronic pain treatment. This Polyanalgesic Consensus Conference (PACC)® project's scope is to provide evidence-based guidance for clinical pharmacology and best practices for intrathecal drug delivery for cancer pain. MATERIALS AND METHODS: Authors were chosen on the basis of their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches using Medline, EMBASE, Cochrane CENTRAL, BioMed Central, Web of Science, Google Scholar, PubMed, Current Contents Connect, Meeting Abstracts, and Scopus from 2017 (when the PACC last published guidelines) to the present. Identified studies were graded using the United States Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations were based on the strength of evidence, and when evidence was scant, recommendations were based on expert consensus. RESULTS: The PACC evaluated the published literature and established evidence- and consensus-based expert opinion recommendations to guide best practices in treating cancer pain. Additional guidance will occur as new evidence is developed in future iterations of this process. CONCLUSIONS: The PACC recommends best practices regarding the use of intrathecal drug delivery in cancer pain, with an emphasis on managing the unique disease and patient characteristics encountered in oncology. These evidence- and consensus-based expert opinion recommendations should be used as a guide to assist decision-making when clinically appropriate.

Ultrasound-guided fascial plane blocks for post-breast surgery pain syndrome.

INTRODUCTION: Persistent pain following breast surgery is common and may be challenging to treat. In patients refractory to conservative treatments, ultrasound-guided fascial plane blocks of thoracic nerves can be a useful option. RESULTS: This type of neuro blockade technique provides advantages in terms of safety and efficacy that are convenient for physicians managing refractory and complex cases of post-breast surgery syndrome. CONCLUSION: This technical review aims to present an up-to-date summary of the most common ultrasound-guided fascial plane blocks for chronic pain in post-breast surgery patients, provide a detailed technical description of each intervention, and propose preferred injections based on the anatomical location of the pain.

Intrathecal Drug Delivery Systems for Cancer Pain Control: Insights on Current Contemporary Practices in the US.

OBJECTIVES: Among patients with cancer with moderate to severe, intractable pain, intrathecal drug delivery using an intrathecal drug delivery system (IDDS) offers effective pain control. In this study, we evaluate the trends of IDDS therapy among patients with cancer, associated comorbidities, complications, and outcomes, using a large representative US administrative inpatient data base. MATERIALS AND METHODS: The Nationwide Inpatient Sample (NIS) data base contains data from 48 states and the District of Columbia. The NIS was used to identify patients with cancer who underwent IDDS implantation between 2016 and 2019. Patients with cancer with intrathecal pumps for the treatment of chronic pain were identified using administrative codes. Baseline demographics, hospital characteristics, type of cancer associated with IDDS implantation, palliative care encounters, hospitalization costs, length of stay, and prevalence of bone pain were evaluated in the study. RESULTS: A total of 22,895 (0.32%) individuals with hospital admission for IDDS surgery were included for analysis among 7.06 million individuals with cancer in the final cohort. The IDDS cohort consisted of patients predominantly in the 65-to-79 years age group (40.49%), female sex (50.42%), and Caucasian ethnicity (75.82%). The top five cancers in patients receiving IDDS were lung (27.15%), colorectal (24.9%), liver (16.44%), bone (8.01%), and liver (7.99%) cancer. In addition, the length of stay was six days (interquartile range [IQR] four-nine days) and the median cost of hospital admission was $29,062 (IQR $19,413-$42,261) in the patients who received an IDDS. These factors were greater than those in patients without IDDS. CONCLUSIONS: A very few patients with cancer received IDDS in the US during the study period. Despite recommendations supporting its use, there are significant racial and socioeconomic disparities in IDDS use.

Exceptional Cases of Spinal Cord Stimulation for the Treatment of Refractory Cancer-Related Pain.

OBJECTIVES: Cancer pain has traditionally been managed with opioids, adjuvant medications, and interventions including injections, neural blockade, and intrathecal pump (ITP). Spinal cord stimulation (SCS), although increasingly used for conditions such as failed back surgery syndrome and complex regional pain syndrome, is not currently recommended for cancer pain. However, patients with cancer-related pain have demonstrated benefit with SCS. We sought to better characterize these patients and the benefit of SCS in exceptional cases of refractory pain secondary to progression of disease or evolving treatment-related complications. MATERIALS AND METHODS: This was a single-center, retrospective case series at a tertiary cancer center. Adults ≥18 years old with active cancer and evolving pain secondary to disease progression or treatment, whose symptoms were refractory to systemic opioids, and who underwent SCS trial followed by percutaneous implantation between 2016 and 2021 were included. Descriptive statistics included mean, SD, median, and interquartile range (IQR). RESULTS: Eight patients met the inclusion criteria. The average age at SCS trial was 60.0 (SD: ±11.6) years, and 50% were men. Compared with baseline, the median (IQR) change in pain score by numeric rating scale (NRS) after trial was -3 (2). At an average of 14 days after implant, the median (IQR) change in NRS and daily oral morphine equivalents were -2 (3.5) and -126 mg (1095 mg), respectively. At a median of 63 days after implant, the corresponding values were -3 (0.75) and -96 mg (711 mg). There was no significant change in adjuvant therapies after SCS implantation at follow-up. Six patients were discharged within two days after implantation. Two patients were readmitted for pain control within the follow-up period. CONCLUSIONS: In patients with cancer-related pain, SCS may significantly relieve pain, reduce systemic daily opioid consumption, and potentially decrease hospital length of stay and readmission for pain control. It may be appropriate to consider an SCS trial before ITP in select cases of cancer-related pain.

A practical access for fluoroscopically-guided percutaneous sacroplasty: Case report.

BACKGROUND: Sacral metastases represent the lowest percentage of invasion to the spine, however, as chemotherapy treatments progress, the cancer survival rate has become higher, and the percentage of sacral metastases has increased. Treatment options for sacrum metastases are surgery, radiotherapy, and minimally invasive techniques such as sacroplasty and radiofrequency ablation. Knowing the repercussions that advancing the needle anteriorly (viscera) or medially (sacral roots) can have during the sacroplasty we are describing a technique to perform c-arm sacroplasty in coaxial vision, to identify the anterior sacral cortical bone that is in the limits of the pelvic viscera as well as the sacral foraminal line. CASE PRESENTATION: In the current report, we present a 75-year-old male patient with prostate cancer metastatic to S1, S2, S3 and iliac, with severe lumbar axial pain VAS 8/10. With a caudal tilt between 35-45 degrees until aligning the sacrum in a coaxial view, a 11-gauge Jamshidi needle is advanced from s3 to s1. The trajectory of the needle during the procedure is corroborated in AP and lateral, S1 is cemented, and the needle is withdrawn to cement S2 and S3. After the sacroplasty with the coaxial access, the patient reported VAS 1-2/10. CONCLUSIONS: It is important to offer an adequate quality of life to patients with sacral fractures, whether associated with cancer or sacral insufficiency fractures (SIF). Sacroplasty, being a recently described technique, can be a very viable option for these patients, that's why it is important to have safe and reliable techniques to complement the approach of this minimally invasive technique.The coaxial access may be a safe and practical way to perform sacroplasty in these patients.

A Review of Laser Therapy and Low-Intensity Ultrasound for Chronic Pain States.

PURPOSE OF REVIEW: Chronic pain management therapies have expanded quickly over the past decade. In particular, the use of laser therapy and ultrasound in the management of chronic pain has risen in recent years. Understanding the uses of these types of therapies can better equip chronic pain specialists for managing complicated chronic pain syndromes. The purpose of this review was to summarize the current literature regarding laser radiation and ultrasound therapy used for managing chronic pain syndromes. RECENT FINDINGS: In summary, there is stronger evidence supporting the usage of laser therapy for managing chronic pain states compared to low-intensity ultrasound therapies. As a monotherapy, laser therapy has proven to be beneficial in managing chronic pain in patients with a variety of pain syndromes. On the other hand, LIUS has less clear benefits as a monotherapy with an uncertain, optimal delivery method established. Both laser therapy and low-intensity ultrasound have proven beneficial in managing various pain syndromes and can be effective interventions, in particular, when utilized in combination therapy.

Ultrasound-Guided Peripheral Nerve Blocks: A Practical Review for Acute Cancer-Related Pain.

PURPOSE OF REVIEW: Ultrasound-guided regional techniques, including catheter-based approaches, are a subset of interventional therapies that have gained interest as an option for managing acute cancer-related pain. The authors sought to review the available published evidence and to discuss practical recommendations for expanding access to such therapies. RECENT FINDINGS: In a MEDLINE/Pubmed search of ultrasound-guided peripheral nerve blocks and peripheral nerve catheters for specific anatomic targets, a total of 28 case reports and case series were identified. Included studies described improved analgesia and reduced opioid requirements with highly variable duration of effect. Current level of evidence remains limited. Pain is a symptom that markedly impacts the quality of life of cancer patients and ultrasound-guided regional techniques are a promising therapeutic option albeit with a limited evidence base. Practical recommendations offered for coordinating access to such therapies in the inpatient, emergency department, and outpatient settings may expand interest and facilitate higher quality research.

Spinal Cord Stimulation in the Treatment of Cancer Pain: A Retrospective Review.

OBJECTIVES: Spinal cord stimulation (SCS) involves electrical stimulation of the dorsal spinal cord to disrupt the transmission of ascending pain signals. SCS has been used successfully to manage a variety of chronic pain conditions, but its efficacy in the treatment of pain syndromes in patients with cancer has not been established because most studies have involved a limited number of patients. The purpose of this study was to assess the efficacy of SCS in a large group of patients with cancer. MATERIALS AND METHODS: A retrospective review was performed for all patients who had SCS trials and implants placed at Memorial Sloan Kettering Cancer Center between 2003 and 2021. Patients were divided into groups based on whether their pain could be directly attributed to cancer or its treatment (cancer dependent, n = 51) and those who had incidental pain unrelated to cancer (cancer independent, n = 22). The cancer-dependent group was further subdivided into those whose pain was directly related to primary tumor invasion or metastasis (cancer related, n = 26) and those whose pain was a result of cancer treatment such as chemotherapy or surgery (treatment related, n = 25). The primary outcomes were changes in pain scores and daily oral morphine equivalents (OMEs) before intervention to one year after implant. Secondary measures included the SCS trial success rate, change in pain scores immediately after the SCS trial, and change in pain scores immediately after the SCS implant. RESULTS: Most patients in the cancer-dependent pain group (59%) and the cancer-independent pain group (68%) had successful SCS trials and subsequently went on to have SCS implants placed. The patients with cancer-dependent pain as a whole had median reduction of 1.5 points (or 23%) on a 10-point pain score immediately after implant (p = 0.001), with the effect diminishing to a median reduction of 1 point (or 15%) by one year after implant (p = 0.027). The cancer-dependent pain groups did not have a significant reduction in daily OMEs, following implantation (p = 0.30), but the cancer-independent group did have a significant reduction (p = 0.01). CONCLUSIONS: SCS can be considered as a treatment modality for patients with cancer whose pain is not adequately controlled with medical therapy or by less invasive interventions.

Effect of a structured stretching exercise program on resolution of myofascial pain and opioid usage in "legacy pain" patients: A retrospective cohort study.

OBJECTIVE: The aim of this study was to determine whether the implementation of a structured exercise stretching routine targeted at resolving myofascial pain is effective in improving outcomes of "legacy pain" patients. DESIGN: Retrospective cohort study. SETTING: Private community-based interventional pain management practice. SUBJECTS: "Legacy pain" patients, defined as patients on opioid therapy for >1 year. METHODS: Subjects were initiated on a structured home exercise stretching routine targeted at resolving myofascial pain consisting of 14 lumbar, four thoracic, and seven cervical stretches as appropriate. Daily morphine milligram equivalent, functional status (Oswestry Disability Index), and pain level (Numeric Rating Scale) were compared pre- and post-treatment at one year. RESULTS: After 1 year, exercise techniques reduced daily morphine milligram equivalent intake on average from 76.3 to 21.0 mg (p < 0.001) with 84.4% of patients decreasing their total opioid dose (p < 0.001) and 34.4% of patients being completely weaned off of opioids (p < 0.001). Numeric Rating Scale of pain and Oswestry Disability Indices were unchanged with treatment, 7.0-6.7 (p = 0.122) and 30.4-29.3 (p = 0.181), respectively. CONCLUSIONS: The addition of a structured stretching exercise program focusing on the resolution of the myofascial pain in the treatment of "legacy pain" patients was shown to significantly reduce and often discontinue opioid use without adversely affecting pain score or functionality.

Considerations in permanent implantation of peripheral nerve stimulation (PNS) for chronic neuropathic pain: An international cross-sectional survey of implanters.

AIM: Novel minimally invasive short-term and long-term peripheral nerve stimulation (PNS) systems have revolutionized targeted treatment of chronic neuropathic pain. We present an international survey of PNS-implanting pain physicians to assess what factors they consider when offering permanent PNS. METHODS: This cross-sectional study consisted of a survey (Qualtrics) that was distributed to PNS-implanting physicians in a device supplier's entire email database on November 13, 2020, with 3 weeks of response time. Physicians' contact information in the form of their email addresses had been previously collected by the supplier upon device distribution with permission to use survey responses for research. RESULTS: Of 2032 database physicians, 40 physicians representing 37 institutions responded to the survey. The most common application of PNS was mononeuropathic pain (57%). The most frequently targeted nerve was the suprascapular nerve (29%). 14% of physicians reported 81-100% of their implants were dual-lead. The representative physicians ranged broadly in their most frequently targeted nerves. Although mononeuropathic pain was the most common indication for PNS, there was still varied response regarding other indications such as CRPS and post-surgical chronic pain. CONCLUSION: In context of a low response rate, identifying such factors can help update the prevailing treatment algorithm for interventional therapies, assist pain physicians in better identifying which patients are the best candidates for PNS, and inform future clinical trial design on PNS efficacy.

Intravenous Ketamine for Cancer Pain Management, Including Flares During the COVID-19 Pandemic: A Retrospective Study.

OBJECTIVES: Cancer-related neuropathic pain (CNP) affects an increasing proportion of cancer patients, given improved survival, but it remains difficult to treat. There are no studies on an extended intravenous ketamine protocol and its synergies with common neuropathy treatments to treat CNP. This study aims to 1) evaluate the safety and effectiveness of an intravenous ketamine protocol to treat refractory CNP and 2) uncover synergies between ketamine and common neuropathy treatments. METHODS: This is a single-center, retrospective review of 57 patients and 192 infusions, with prospective follow-up on 14 enrolled patients during the coronavirus disease 2019 (COVID-19) pandemic. RESULTS: The etiologies of CNP were as follows: 13 from tumor compression, 25 with chemotherapy-induced peripheral neuropathy, 13 from surgery, and 6 from radiation therapy. Overall, 42 of 57 patients (73.7%) were responders, and 71.8% of responders received >3 weeks of pain relief on their last infusion. Analysis of adjuvant treatments revealed that the combination of serotonin-norepinephrine reuptake inhibitors and ketamine resulted in an increase in responders compared with nonresponders (P < 0.01). Adverse events occurred in 32 of 192 infusions (16.7%). All side effects self-resolved or resolved with intervention per the adverse events protocol. During the pandemic, all 14 currently enrolled patients did not receive ketamine infusions. Thirteen of the 14 patients returned to baseline pain, with 61.5% increasing medications. All experienced worsened function, mobility, mood, or anorexia. CONCLUSION: Intravenous ketamine may be a safe and effective adjuvant treatment for CNP, especially with serotonin-norepinephrine reuptake inhibitors. Larger, prospective studies are warranted and should explore parameters to help prognosticate response to ketamine infusions.

An Interventional Pain Algorithm for the Treatment of Postmastectomy Pain Syndrome: A Single-Center Retrospective Review.

OBJECTIVE: Breast cancer is the most common female malignancy worldwide. Breast surgery and adjuvant oncological therapies are often required to increase survival. Treatment-related pain may persist and evolve into postmastectomy pain syndrome (PMPS) in a significant subset of breast cancer survivors. In this retrospective investigation, we will present our experience in applying an interventional algorithmic approach to treat PMPS. DESIGN: A retrospective study. SETTING: An academic cancer hospital. SUBJECTS: Adult females with PMPS diagnosis. METHODS: We reviewed 169 records with the diagnosis of PMPS from 2015 to 2019 within our health system. Pre- and post-injection pain scores, relief duration, and medication usage changes were collected. The decision to perform each procedure was based on the anatomic location of the painful area with the corresponding peripheral sensory innervation. Decision-making flow diagrams were created to present our experience in managing PMPS beyond peripheral nerve blocks. RESULTS: Ultrasound-guided peripheral nerve block results (n=350) were analyzed. The mean baseline pain score was 7, compared with the post-treatment mean score of 3 (95% confidence interval: 3.58 to 3.98, P = 0.0001). Among the responders, the mean pain relief duration was 45 days, with a median of 84 days. Opioid medication consumption was reduced by 11% (t = 0.72, P = 0.47). CONCLUSIONS: Ultrasound-guided nerve blocks of this area could be performed safely and effectively after breast surgeries. We also present our proposed algorithm to provide a stepwise application for selecting the appropriate therapies in the management of more complex PMPS.

Recent Advances in Peripheral Opioid Receptor Therapeutics.

PURPOSE OF REVIEW: Although opioids are excellent analgesics, they are associated with severe short- and long-term side effects that are especially concerning for the treatment of chronic pain. Peripherally acting opioid receptor agonists promise to mitigate the more serious centrally mediated side effects of opioids, and the goal of this paper is to identify and elaborate on recent advances in these peripheral opioid receptor therapeutics. RECENT FINDINGS: Peripheral opioid receptor agonists are effective analgesics that at the same time circumvent the problem of centrally mediated opioid side effects by (1) preferentially targeting peripheral opioid receptors that are often the source of the pain and (2) their markedly diminished permeability or activity across the blood-brain barrier. Recent novel bottom-up approaches have been notable for the design of therapeutics that are either active only at inflamed tissue, as in the case of fentanyl-derived pH-sensitive opioid ligands, or too bulky or hydrophilic to cross the blood-brain barrier, as in the case of morphine covalently bound to hyperbranched polyglycerols. Recent innovations in peripheral opioid receptor therapeutics of pH-sensitive opioid ligands and limiting opioid permeability across the blood-brain barrier have had promising results in animal models. While this is grounds for optimism that some of these therapeutics will be efficacious in human subjects at a future date, each drug must undergo individualized testing for specific chronic pain syndromes to establish not only the nuances of each drug's therapeutic effect but also a comprehensive safety profile.

Tapentadol, Buprenorphine, and Levorphanol for the Treatment of Neuropathic Pain: a Systematic Review.

PURPOSE OF REVIEW: The objective of this systematic review is to present the available evidence for the utilization of the atypical opioids tapentadol, buprenorphine, and levorphanol for the treatment of neuropathic pain. RECENT FINDINGS: In total, 1619 articles were retrieved of which 10 studies were included. Of 5 included studies pertaining to tapentadol, 4 studies show tapentadol monotherapy to be effective for the treatment of diabetic peripheral neuropathy or chronic, radiating low back pain. Of the 3 studies included for buprenorphine, only one was a randomized controlled trial found not to have a statistically significant reduction in pain with TD buprenorphine likely due to very high withdrawal rates during the trial. Only 2 case reports were included from the available literature for levorphanol providing low-quality anecdotal evidence. The role of tapentadol, buprenorphine, and levorphanol for neuropathic pain conditions requires robust research including randomized controlled trials to evaluate their efficacy and safety.

Dual Enkephalinase Inhibitors and Their Role in Chronic Pain Management.

PURPOSE OF REVIEW: Dual enkephalinase inhibitors (DENKIs) are pain medications that indirectly activate opioid receptors and can be used as an alternative to traditional opioids. Understanding the physiology of enkephalins and their inhibitors and the pharmacology of these drugs will allow for proper clinical application for chronic pain patients in the future. RECENT FINDINGS: DENKIs can be used as an alternative mode of analgesia for patients suffering from chronic pain by preventing the degradation of endogenous opioid ligands. By inhibiting the two major enkephalin-degrading enzymes (neprilysin and aminopeptidase N), DENKIs can provide analgesia with less adverse effects than nonendogenous opioids. The purpose of this paper is to review the current literature investigating DENKIs and explore their contribution to chronic pain management.

Flavonoids in the Treatment of Neuropathic Pain.

PURPOSE OF REVIEW: Chronic pain continues to present a large burden to the US healthcare system. Neuropathic pain, a common class of chronic pain, remains particularly difficult to treat despite extensive research efforts. Current pharmacologic regimens exert limited efficacy and wide, potentially dangerous side effect profiles. This review provides a comprehensive, preclinical evaluation of the literature regarding the role of flavonoids in the treatment of neuropathic pain. RECENT FINDINGS: Flavonoids are naturally occurring compounds, found in plants and various dietary sources, which may have potential benefit in neuropathic pain. Numerous animal-model studies have demonstrated this benefit, including reversal of hyperalgesia and allodynia. Flavonoids have also exhibited an anti-inflammatory effect relevant to neuropathic pain, as evidenced by the reduction in multiple pro-inflammatory mediators, such as TNF-α, NF-κB, IL-1ß, and IL-6. Flavonoids represent a potentially new treatment modality for neuropathic pain in preclinical models, though human clinical evidence is yet to be explored at this time.

Interventional Therapies for Pain in Cancer Patients: a Narrative Review.

PURPOSE OF REVIEW: Pain is a prevalent symptom in the lives of patients with cancer. In light of the ongoing opioid epidemic and increasing awareness of the potential for opioid abuse and addiction, clinicians are progressively turning to interventional therapies. This article reviews the interventional techniques available to mitigate the debilitating effects that untreated or poorly treated pain have in this population. RECENT FINDINGS: A range of interventional therapies and technical approaches are available for the treatment of cancer-related pain. Many of the techniques described may offer effective analgesia with less systemic toxicity and dependency than first- and second-line oral and parenteral agents. Neuromodulatory techniques including dorsal root ganglion stimulation and peripheral nerve stimulation are increasingly finding roles in the management of oncologic pain. The goal of this pragmatic narrative review is to discuss interventional approaches to cancer-related pain and the potential of such therapies to improve the quality of life of cancer patients.

Recent Advances in the Treatment of Opioid Use Disorder.

PURPOSE OF REVIEW: Opioid use disorder (OUD) remains a national epidemic with an immense consequence to the United States' healthcare system. Current therapeutic options are limited by adverse effects and limited efficacy. RECENT FINDINGS: Recent advances in therapeutic options for OUD have shown promise in the fight against this ongoing health crisis. Modifications to approved medication-assisted treatment (MAT) include office-based methadone maintenance, implantable and monthly injectable buprenorphine, and an extended-release injectable naltrexone. Therapies under investigation include various strategies such as heroin vaccines, gene-targeted therapy, and biased agonism at the G protein-coupled receptor (GPCR), but several pharmacologic, clinical, and practical barriers limit these treatments' market viability. This manuscript provides a comprehensive review of the current literature regarding recent innovations in OUD treatment.

Ultrasound-Guided Peripheral Nerve Stimulation of Cervical, Thoracic, and Lumbar Spinal Nerves for Dermatomal Pain: A Case Series.

OBJECTIVES: With the development of percutaneously inserted devices, peripheral nerve stimulation (PNS) has been gaining attention within chronic pain literature as a less invasive neurostimulation alternative to spinal column and dorsal root ganglion stimulation. A majority of current PNS literature focuses on targeting individual distal nerves to treat individual peripheral mononeuropathies, limiting its applications. This article discusses our experience treating dermatomal pain with neurostimulation without needing to access the epidural space by targeting the proximal spinal nerve with peripheral nerve stimulation under ultrasound-guidance. MATERIALS AND METHODS: A temporary, percutaneous PNS was used to target the proximal spinal nerve in 11 patients to treat various dermatomal pain syndromes in patients seen in an outpatient chronic pain clinic. Four patients received stimulation targeting the lumbar spinal nerves and seven patient received stimulation targeting the cervical or thoracic spinal nerves. RESULTS: The case series presents 11 cases of PNS of the proximal spinal nerve. Seven patients, including a majority of the patients with lumbar radiculopathy, had analgesia during PNS. Four patients, all of whom targeted the cervical or thoracic spinal nerves, did not receive analgesia from PNS. CONCLUSION: PNS of the proximal spinal nerve may be an effective modality to treat dermatomal pain in patients who are not candidates for other therapies that require access to the epidural space. This technique was used to successfully treat lumbar radiculopathy, post-herpetic neuralgia, and complex regional pain syndrome.