Peripheral Nerve Stimulation for Pain Management: A Survey of Clinical Practice Patterns.

BACKGROUND: Clinical interest in and utilization of peripheral nerve stimulation (PNS) for treating chronic pain has significantly increased in recent years owing to its potential for providing analgesia and improved function and quality of life in comparison with pharmacologic treatments. However, the relative infancy of PNS-specific systems and limited clinical practice guidance likely contribute to significant variation in PNS utilization patterns. OBJECTIVES: We sought to conduct a survey study to characterize PNS-specific clinical practices and propose the next steps in standardizing key practices for PNS utilization. MATERIALS AND METHODS: A 19-question survey exploring PNS-relevant clinical parameters was disseminated online to pain physicians in practice. Descriptive statistics were used to summarize results. RESULTS: A total of 94 responses were collected. Regarding patient selection, most practitioners would apply PNS to treat nociceptive pain from major joint osteoarthritis (77.7%) and chronic low back pain (64.9%), but not for axial neck pain (50.0%). In contrast, most would apply PNS to treat neuropathic pain from peripheral neuralgia (94.7%), pericranial neuralgia (77.7%), and cancer-related neuropathic pain (64.9%). In treating complex regional pain syndrome, most practitioners would apply PNS before all other forms of neuraxial neuromodulation (>50% for each form). Similarly, for treating nonsurgical low back pain, most would apply PNS before neuraxial neuromodulation (>50% for each form) but not before radiofrequency ablation (19.2%). Most routinely performed nerve blocks before PNS, mainly to confirm anatomical coverage (84.0%), and regarded a 50% to 75% interquartile range as the minimum analgesic benefit required before proceeding with PNS. Regarding nerve target selection for treating complex regional pain syndrome of the wrist/hand or ankle/foot, or knee osteoarthritis, we observed a very wide variance of PNS target locations and discrete nerves. Regarding "minor" adverse events, most reported not changing PNS utilization on encountering skin/soft tissue reactions (85.1%), minor infections (76.6%), or lead migration/loss of efficacy (50.0%). In comparison, most reported reducing PNS utilization on encountering skin erosion (58.5%), major infections (58.5%), or lead fractures (41.5%). CONCLUSIONS: There is significant practice variation regarding the utilization of PNS across numerous key clinical considerations. Future research that explores the reasons driving these differences might help optimize patient selection, target selection, periprocedural management, and ultimately outcomes.

Sustained relief with spinal cord stimulator despite anterior lead migration: a case report.

Lead migration is a common complication of spinal cord stimulation, although anterior migration is rare. While early studies suggested that anterior stimulation may produce analgesic effects, it is thought to be poorly tolerated due to abnormal paresthesia and muscle contractions due to its proximity to the corticospinal tract. This case report presents a unique case of sustained pain relief despite anterior lead migration, which suggests that anterior column stimulation may hold clinical significance for pain management. Further studies are needed to explore its analgesic mechanisms and potential therapeutic application. Strategies to prevent lead migration, particularly in the early postoperative period, are also crucial for optimizing outcomes.

A case of ongoing pain relief with spinal cord stimulation despite significant lead movement: Spinal cord stimulation is widely used for different pain syndromes. Although it is generally considered safe and minimally invasive, complications can occur including the movement of the leads, which may result in the loss of pain relief. Lead movement into the front (anterior) part of the spinal cord is extremely rare and has been associated with unpleasant sensation and muscle tightening as this area controls body movement. This case report describes a patient who continued to experience pain relief without any side effects even after the leads had moved into the anterior space. It is suggested that stimulating the anterior spinal cord may have more potential benefits than previously believed. This case highlights the need for further research into the anterior stimulation and its possible side effects.

Suprascapular nerve peripheral nerve stimulation for pediatric cancer pain: a case series.

Aim: Despite the growing evidence supporting the use of peripheral nerve stimulation (PNS) for cancer pain in adults, it is underutilized in the pediatric oncology population.Method: We describe the use of temporary, percutaneous PNS for pain management in pediatric patients suffering from cancer related pain.Results: Two adolescent patients underwent an ultrasound-guided suprascapular nerve PNS placement utilizing the percutaneous 60-day therapy system. Both patients reported approximately 60% pain relief during the therapy, as well as up to 90 days post lead removal.Conclusion: PNS may play a crucial role in the pediatric oncology population. Further studies are warranted to investigate the efficacy and safety of PNS for various cancer-related pain conditions in pediatric populations.

Peripheral nerve stimulator is a device that uses electrical impulses to stimulate the nerves that send pain signals to the brains. This device may be useful in treating pain in cancer patients. We highlight two pediatric cancer patients that had pain relief using a specific type of peripheral nerve stimulator that is removed after 60 days. It is thought that pain relief is sustained even after removing the stimulator by altering the pain signals to the brain. This treatment may serve an important role in treating pediatric cancer pain.

Multidevice spinal cord stimulation trials: shared decision making in the era of multiple neuromodulation paradigms.

Aim: There is a lack of evidence-based standards for matching spinal cord stimulation (SCS) paradigm to individual patients. We aim to determine the feasibility and safety of a new alternative trial strategy, a sequential multidevice trial.Materials & methods: A retrospective analysis was performed on 116 patients who underwent SCS trials, single device or sequential multidevice (tonic and high-frequency), for chronic low back pain to assess feasibility and compare trial-to-implantation rate and explantation rate.Results: Multidevice SCS trials are feasible and safe. There was no statistically significant difference in the trial-to-implantation and explantation rates between the two groups.Conclusion: Multidevice SCS trial, prioritizing patient preference, may serve as an alternative trial strategy to improve long-term success of SCS.

Spinal cord stimulation plays an important role in the management of chronic low back pain refractory to conventional treatment. The current standard of practice is to try one device for 3­7 days prior to implantation. In the setting of increasing number of device options, we believe that a new trial method may be necessary to improve patient exposure to different options, thus improving informed decisions based on their personal experiences. Our study supports that this new trial method with different devices is feasible and safe.

Association between electrodiagnosis and neuromuscular ultrasound in the diagnosis and assessment of severity of carpal tunnel syndrome.

BACKGROUND: Neuromuscular ultrasound plays an increasing role in diagnosing carpal tunnel syndrome (CTS). There are limited data supporting the correlation between the electrodiagnostic studies and ultrasound measurements in CTS. OBJECTIVE: To assess the association between different electrodiagnostic severities and ultrasound measurements of the median nerve in CTS. DESIGN: A retrospective cohort study. SETTING: An academic tertiary care center. PATIENTS: Patients 18 years or older evaluated with upper limb electrodiagnostic studies and neuromuscular ultrasound. MAIN OUTCOME MEASUREMENT: Ultrasound measurements of the median nerve cross-sectional area (CSA) at the wrist and the calculated wrist-to-forearm ratio (WFR) were compared with the electrodiagnostic severity (normal, mild, moderate, and severe). Mean analysis and analysis of variance test (α = 0.05) were performed to assess the association. RESULTS: A total of 1359 limbs were identified. There was a statistically significant association between electrodiagnostic severity of CTS and median nerve CSA at the wrist (p < .001), as well as the WFR (p < .001). The mean median nerve CSA at the wrist and WFR were 7.01 ± 2.06 mm2 (95% CI: 6.80-7.20) and 1.24 ± 0.36 (95% CI: 1.16-1.24) in electrodiagnostically normal median nerves, 10.47 ± 2.82 mm2 (95% CI: 10.25-10.75) and 2.06 ± 0.67 (95% CI: 2.04-2.16) in electrodiagnostically mild CTS, 12.95 ± 4.74 mm2 (95% CI: 12.41-13.59) and 2.49 ± 1.04 (95% CI: 2.37, 2.63) in electrodiagnostically moderate CTS, and 14.69 ± 5.38 mm2 (95% CI: 13.95-15.44) and 2.71 ± 1.02 (95% CI: 2.56-2.84) in electrodiagnostically severe CTS, respectively. CONCLUSION: This study suggests a direct association between electrodiagnostic severity and ultrasound measurements of the median nerve in patients with suspected CTS.

Non-inferiority study assessing the utility of postcervical and lumbar radiofrequency ablation steroid use.

INTRODUCTION: Many physicians administer steroids after radiofrequency ablation (RFA) to mitigate postprocedural inflammation and decrease postprocedural pain. However, robust evidence supporting the benefits of steroids after RFA is lacking and steroids have risks. METHODS: This study was a single-center, prospective, observational study designed to assess whether RFA alone is inferior to RFA with steroids for postprocedure pain. Eligible patients were at least 18 years of age and scheduled to undergo cervical or lumbar RFA. The primary outcome measure was the average pain score on the numeric rating scale (NRS) 7 days after the RFA. The secondary outcome measures included anxiety, depression and physical function, measured via the Patient-Reported Outcomes Measurement Information System short forms. All outcome measures were completed prior to the procedure and at 7 and 60 days postprocedure. RESULTS: Out of the 365 participants who completed baseline assessments, 175 received steroids and 190 did not receive steroids. The pain intensity at 7 days postprocedure was similar between the steroid and non-steroid groups (mean difference (steroid-non-steroid): -0.23). The 95% CI of the estimate (-0.76 to 0.30) was within the prespecified non-inferiority margin of 1.5 NRS points. Similar results were obtained for pain at 60 days (mean difference: 0.09; 95% CI -0.48 to 0.65). No significant differences between groups were observed for anxiety, depression or physical function at either 7 or 60 days. CONCLUSION: This study suggests that the addition of steroids to the RFA procedure does not provide added benefits and is therefore not worth the additional risks that they pose.

Expectations for Improvement: A Neglected but Potentially Important Covariate or Moderator for Chronic Pain Clinical Trials.

Variability in pain-related outcomes can hamper assay sensitivity of chronic pain clinical trials. Expectations of outcome in such trials may account for some of this variability, and thereby impede development of novel pain treatments. Measurement of participants' expectations prior to initiating study treatment (active or placebo) is infrequent, variable, and often unvalidated. Efforts to optimize and standardize measurement, analysis, and management of expectations are needed. In this Focus Article, we provide an overview of research findings on the relationship between baseline expectations and pain-related outcomes in clinical trials of pharmacological and nonpharmacological pain treatments. We highlight the potential benefit of adjusting for participants' expectations in clinical trial analyses and draw on findings from patient interviews to discuss critical issues related to measurement of expectations. We conclude with suggestions regarding future studies focused on better understanding the utility of incorporating these measures into clinical trial analyses. PERSPECTIVE: This focus article provides an overview of the relationship between participants' baseline expectations and pain-related outcomes in the setting of clinical trials of chronic pain treatments. Systematic research focused on the measurement of expectations and the impact of adjusting for expectations in clinical trial analyses may improve assay sensitivity.

The American Society of Pain and Neuroscience (ASPN) Evidence-Based Clinical Guideline of Interventional Treatments for Low Back Pain.

Introduction: Painful lumbar spinal disorders represent a leading cause of disability in the US and worldwide. Interventional treatments for lumbar disorders are an effective treatment for the pain and disability from low back pain. Although many established and emerging interventional procedures are currently available, there exists a need for a defined guideline for their appropriateness, effectiveness, and safety. Objective: The ASPN Back Guideline was developed to provide clinicians the most comprehensive review of interventional treatments for lower back disorders. Clinicians should utilize the ASPN Back Guideline to evaluate the quality of the literature, safety, and efficacy of interventional treatments for lower back disorders. Methods: The American Society of Pain and Neuroscience (ASPN) identified an educational need for a comprehensive clinical guideline to provide evidence-based recommendations. Experts from the fields of Anesthesiology, Physiatry, Neurology, Neurosurgery, Radiology, and Pain Psychology developed the ASPN Back Guideline. The world literature in English was searched using Medline, EMBASE, Cochrane CENTRAL, BioMed Central, Web of Science, Google Scholar, PubMed, Current Contents Connect, Scopus, and meeting abstracts to identify and compile the evidence (per section) for back-related pain. Search words were selected based upon the section represented. Identified peer-reviewed literature was critiqued using United States Preventive Services Task Force (USPSTF) criteria and consensus points are presented. Results: After a comprehensive review and analysis of the available evidence, the ASPN Back Guideline group was able to rate the literature and provide therapy grades to each of the most commonly available interventional treatments for low back pain. Conclusion: The ASPN Back Guideline represents the first comprehensive analysis and grading of the existing and emerging interventional treatments available for low back pain. This will be a living document which will be periodically updated to the current standard of care based on the available evidence within peer-reviewed literature.

Complete sternal-sparing left ventricular assist device implantation is associated with improved postoperative mobility.

Left ventricular assist device (LVAD) implantation via a complete sternal-sparing (CSS) technique is gaining interest due to several potential benefits. We hypothesized that the CSS approach for HeartMate 3 (HM3) LVAD implantation improves postoperative mobility and physical independence compared to full sternotomy (FS). We retrospectively reviewed patients who were implanted with a commercial HM3 at our institution from September 2017 to August 2018. The Activity Measure for Post-Acute Care short forms and Functional Independence Measure scores were used to assess the patient's physical limitations postoperatively. A total of 43 patients were included in the study: 27 (63%) CSS patients and 16 (37%) FS patients. At postoperative day 3, the CSS cohort demonstrated improved mobility based on Activity Measure for Post-Acute Care scores compared to the FS group; 40% of the CSS cohort versus 67% of the FS cohort remained 100% impaired. The CSS cohort also demonstrated greater postoperative independence in the Functional Independence Measure sit-to-stand metric with 78% of the CSS cohort achieving modified or complete independence by postoperative day 15 compared to only 21% of the FS patients. These early data suggest that the CSS approach for HM3 LVAD implantation improves postoperative mobility and functional independence compared to FS.