Temporary Peripheral Nerve Stimulation as Treatment for Chronic Pain.

INTRODUCTION: Chronic pain is a growing problem across the world, and in the midst of an opioid epidemic, it is imperative that alternative treatment measures are identified to help alleviate the pain experienced by these patients. Chronic pain greatly affects ones quality of life and many patients do not experience adequate relief with conventional treatment measures. The purpose of this retrospective analysis is to assess the efficacy of peripheral nerve stimulation (PNS) therapy in adult patients suffering from chronic pain refractory to conventional treatment measures who underwent therapy on various anatomical locations. METHODS: This retrospective analysis consisted of data collected from electronic health records for n = 89 patients who underwent PNS therapy. Data collected relates to patient age, sex, weight, height, body mass index (BMI), diagnosis, targeted nerves, follow-up encounters, pain scores from before and after PNS therapy, and duration of improvement. Statistical analysis used SPSS software, version 26 (IBM), using a paired t test to assess significance between pre and post PNS therapy pain scores. P values were significant if found to be ≤ 0.05. Further analysis assessed the correlation between age and BMI with visual analog scale (VAS) pain improvement and subjective percentage pain relief. RESULTS: The mean pre-operative (pre-op) pain score before PNS therapy was 6.36 (standard deviation (SD) = 2.18, SEM = 0.23) and the mean post-operative (post-op) pain score after PNS therapy was 4.19 (SD = 2.70, SEM = 0.29). The mean patient-reported percent improvement in pain following PNS therapy was 49.04% (SD = 34.79). The improvement in pain scores between pre-op and post-op was statistically significant (M = 2.17, SD = 2.82, SEM = 0.30, t(88) = 7.26, p < .001), 95% confidence interval (CI) [1.57, 2.76]. The mean duration of improvement for patients was 123 days after therapy initiation (min = 6, max = 683, SD = 126). CONCLUSIONS: This study demonstrated the potential role for PNS therapy in improving patient-reported pain levels for various neuropathies, targeting various nerves. With PNS therapy's use as a chronic pain treatment and available research being limited, further study needs to be done on the efficacy of PNS therapy for pain management and complications associated with PNS device placements at various locations.

Cooled Radiofrequency Ablation for Intercostal Neuralgia.

Background: Intercostal neuralgia is pain associated with the intercostal nerves along the rib, chest, and upper abdominal wall. Intercostal neuralgia has various etiologies, and current conventional treatment options include intercostal nerve blocks, nonsteroidal anti-inflammatory drugs, transcutaneous electrical nerve stimulation, topical medications, opioids, tricyclic antidepressants, and anticonvulsants. For a subset of patients, these conventional treatment options provide little relief. Radiofrequency ablation (RFA) is an emerging procedure for the treatment of chronic pain and neuralgias. Cooled RFA (CRFA) is a specific type of RFA that has been trialed as a treatment for intercostal neuralgia in patients refractory to conventional treatment modalities. This case series assesses the efficacy of CRFA for the treatment of intercostal neuralgia in 6 patients. Case Series: Three female and 3 male patients underwent CRFA of the intercostal nerves to treat intercostal neuralgia. The patients had an average age of 50.7 years and demonstrated an average pain reduction of 81.3%. Conclusion: This case series suggests that CRFA may be an effective treatment option for patients with intercostal neuralgia that is not responsive to conservative treatment options. To determine the duration of pain improvement, large research studies need to be conducted.

Use of Spinal Cord Stimulators in Patients With Pacemakers or Implantable Cardiac Defibrillators: A Review of Documented Accounts of Interference.

OBJECTIVES: To assess the currently available evidence regarding associations between spinal cord stimulator (SCS) lead type, clinical indications for device placement, and interference between SCSs and cardiac pacemakers (CPMs)/implantable cardioverter-defibrillators (ICDs). STUDY DESIGN: Review of case reports and original research studies assessing the interference between SCS and CPM/ICD. MATERIALS AND METHODS: PubMed and Cochrane databases were searched for articles commenting on the interference between SCS and CPM/ICD. The search criteria which generated the greatest number of relevant studies was (spinal cord stimulator AND [pacemaker OR implantable cardioverter defibrillator]). Additional, empiric review was conducted using JSTOR, ScienceDirect, and EBSCOhost databases; however, no additional eligible studies were identified. Data were extracted, summarized into tables, and quantitatively analyzed using LibreTexts and MedCalc software. RESULTS: There was no statistically significant interference observed between SCS and CPM/ICD devices in patients regardless of indication for SCS placement and SCS lead polarity. LIMITATIONS: Limited by variability of patient cases and variability in maximum frequency and amplitude of SCS devices tried in individual cases. Also limited by small sample size and the absence of a standard definition for device interference across studies. CONCLUSIONS: Interference between cardiac devices and SCSs is a rare occurrence. As there are currently no published guidelines, devices should be interrogated on a case-by-case basis in the SCS trial period (if implanted after cardiac device), during permanent implantation, and during scheduled follow-up visits. Peri-operative testing should include increasing the SCS settings to maximally tolerated levels with cardiac device set at its maximum sensitivity.

Pulsed Radiofrequency for the Treatment of Trigeminal Neuralgia.

PURPOSE OF REVIEW: Trigeminal neuralgia is a sudden, unilateral, stabbing pain in the distribution of one or more branches of the fifth cranial nerve, with an overall prevalence ranging between 0.03 and 0.3%. While conservative treatments may offer temporary relief, many patients experience chronic headaches associated with their neuralgia. Invasive treatments are available for patients with intractable neuralgia; however, they may cause permanent tissue damage and often do not provide relief. This article examines pulsed radiofrequency (PRF) ablation (RFA) of the trigeminal nerve as a minimally invasive procedure that offers a promising alternative to invasive procedures for relief of trigeminal neuralgia while minimizing tissue damage. RECENT FINDINGS: Efficacy of PRF and RFA in treating trigeminal neuralgia has been studied before, but literature lacks large size studies. The results of this retrospective study indicate that PRF can be used as a safe and effective treatment for patients suffering from trigeminal neuralgia that is refractory to conservative measures.

Lumbar Level Peripheral Nerve Stimulation for Low Back Pain.

Background: Low back pain affects the lives of millions of people in the United States and the world. Not only does low back pain affect the quality of life for the individual patient, but it also accounts for many emergency department and health care visits. For a subset of patients, conservative measures such as medications and physical therapy, nonsurgical interventions, and surgery are not effective. Peripheral nerve stimulation is an emerging treatment option for patients with chronic low back pain. This case series assesses 6 patients' experiences with lumbar level peripheral nerve stimulation. Case Report: Three male and 3 female patients underwent lumbar level peripheral nerve stimulation as a treatment for chronic low back pain. The average age of the patients was 63.5 years, and they demonstrated an average pain reduction of 64.8%. Conclusion: This series provides evidence that lumbar level peripheral nerve stimulation may be an efficacious treatment for chronic low back pain that is refractory to conservative measures. Large studies are needed to assess the outcomes and durations of improvement associated with this treatment.

Radiofrequency Ablation for the Knee Joint: A Survey by the American Society of Pain and Neuroscience.

Background: Genicular nerve radiofrequency ablation (RFA) is an effective, minimally invasive procedure often used to treat patients with intractable knee pain secondary to knee osteoarthritis and failed knee replacements. The prevalence of knee pain in adults has been estimated to be as high as 40% and is continuously increasing with an aging population. Over the past two decades, proceduralists have adopted variations in patient preparation, procedural steps, and post-operative care for genicular nerve RFA procedures. A survey was dispensed via the American Society of Pain and Neuroscience (ASPN) to gain a popular assessment of common practices for genicular nerve RFA. Methods: A 29 question survey was dispensed via SurveyMonkey to all members of ASPN. Members were able to respond to the survey a single time and were unable to make changes to their responses once the survey was submitted. After responses were compiled, each question was assessed in order to determine common practices for genicular nerve RFA. Results: A total of 378 proceduralists responded to the survey. There was high consensus with the three most commonly targeted nerves. The inferomedial, superomedial, and superolateral genicular branches were treated by 95-96% of respondents, while other targets were less commonly treated. There remains some debate among proceduralists regarding the need for a second diagnostic nerve block and the type of steroid used for diagnostic nerve blocks. Conclusion: Pain physicians use a wide variety of methods to perform genicular nerve ablations. The data offered by the survey show that there is no standardized protocol when it comes to treating knee pain via genicular nerve block and ablation and highlights controversies among proceduralists that ought to serve as the targets of future clinical research aimed at establishing a standardized protocol.

Post-COVID Pain Syndromes.

Although the number of SARS-CoV-2 new cases may be declining due to the implementation of the vaccine in the USA, there is a rising cohort of people with long-term effects from the virus. These long-term effects include loss of taste, heart palpitations, and chronic pain syndromes. In this commentary, we assess the current literature to appraise the knowledge of long-term COVID-19 effects related to long-term pain syndromes including testicular pain, headache, chronic pain, and chest pain.

Radiofrequency Ablation of the Trochanteric Branches of the Femoral Nerve for the Treatment of Greater Trochanteric Syndrome.

BACKGROUND: Approximately 10-15% of the population over the age of 60 suffers from hip pain. Greater trochanteric pain syndrome (GTPS) is one of the most common diagnoses in patients with chronic hip pain, includes a number of disorders, and has a broad differential diagnosis. Conservative managements of GTPS, including pharmacologic interventions, physical therapy, chiropractic intervention, acupuncture, and more invasive techniques, such as intra-articular injections, commonly fail to provide patients with sufficient, long-term relief. While radiofrequency ablation (RFA) has been used to treat intra-articular hip pain in the past, there is little evidence for the feasibility of RFA for managing patients with GTPS. This case series builds on previous evidence that cooled radiofrequency ablation (CRF) of the trochanteric branch of the femoral nerve may offer patients with GTPS effective, safe, and lasting pain improvement. CASES: A series of eight patients with GTPS underwent CRF of the nervus females to the trochanter. CRF procedures were either targeted at the left, right, or bilateral nerves. CONCLUSION: This case series provides additional evidence for the safety and effectiveness of CRF of the nervus femoralis to the trochanter for offering long-term pain relief in patients with GTPS. All patients experienced at least two months of relief, with most patients experiencing ongoing relief from the procedure.