Comparison of tibial nerve pulsed radiofrequency and intralesional radiofrequency thermocoagulation in the treatment of painful calcaneal spur and plantar fasciitis: a randomized clinical trial.

OBJECTIVE: Ultrasound-guided tibial nerve pulsed radiofrequency (US-guided TN PRF) and fluoroscopy-guided intralesional radiofrequency thermocoagulation (FL-guided intralesional RFT) adjacent to the painful calcaneal spur are two interventions for pain management in painful calcaneal spur and plantar fasciitis. This study aimed to compare the effectiveness of the two procedures. DESIGN: A prospective, randomized, single-blind study. SETTING: Single-center pain clinic. SUBJECTS: Forty-nine patients who met the inclusion criteria were randomized into two groups. METHODS: Group U (25 patients) received US-guided TN PRF at 42°C for 240 s, whereas Group F (24 patients) received FL-guided intralesional RFT at 80°C for 90 s. The most severe numeric rating scale (NRS) score during the first morning steps and the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores were used to evaluate the effectiveness of the procedures. The study's primary outcome assessed treatment effectiveness via the NRS, whereas the secondary outcomes included changes in the AOFAS score and the incidence of procedure-related mild adverse events. RESULTS: NRS and AOFAS scores significantly improved in Groups U and F at 1 and 3 months compared with baseline (P < .05), and there was no significant difference between the groups. At month 1, 50% or greater pain relief was achieved in 72% of patients in Group U and 75% of patients in Group F. No significant difference was observed in the incidence of mild adverse events between the groups. CONCLUSIONS: US-guided TN PRF and FL-guided intralesional RFT have shown significant effectiveness in the treatment of painful calcaneal spur and plantar fasciitis. Larger randomized controlled trials are needed. CLINICAL TRIAL NUMBER: NCT06240507.

Predictive value of S100B and brain derived neurotrophic factor for radiofrequency treatment of lumbar disc prolapse.

BACKGROUND: This work aimed to analyze serum S100B levels and brain-derived neurotrophic factor (BDNF) in patients with lumbar disc prolapse to test their predictive values concerning the therapeutic efficacy of pulsed radiofrequency. METHODS: This prospective interventional study was carried out on 50 patients candidates for radiofrequency for treating symptomatic lumbar disc prolapse. Pain severity and functional disability were assessed using the Numeric Rating Scale (NRS) and Functional rating index (FRI) before as well as two weeks, 1, 3, and 6 months after the radiofrequency. Quantitative assessment of serum S100B level and BDNF was done for all the included patients one day before radiofrequency. RESULTS: The scores of NRS and FRI were significantly improved at two weeks, 1, 3, and 6 months following radiofrequency (P-value < 0.001 in all comparisons). Statistically significant positive correlations were found between duration of pain, NRS, and S100B serum level before radiofrequency, and both NRS (P-value = 0.001, 0.035, < 0.001 respectively) and FRI (P-value = < 0.001, 0.009, 0.001 respectively) 6 months following radiofrequency. Whereas there were statistically significant negative correlations between BDNF serum level before radiofrequency and both NRS and FRI 6 months following radiofrequency (P-value = 0.022, 0.041 respectively). NRS and S100B serum levels before radiofrequency were found to be independent predictors of NRS 6 months following radiofrequency (P-value = 0.040. <0.001, respectively). CONCLUSION: Serum level of S100B is a promising biomarker that can predict functional outcomes after pulsed radiofrequency in patients with lumbar disc prolapse.

Effects of Pulsed Radiofrequency Duration in Patients With Chronic Lumbosacral Radicular Pain: A Randomized Double-Blind Study.

OBJECTIVES: We hypothesized that the duration of pulsed radiofrequency (PRF) application may affect the effectiveness of PRF in patients with chronic lumbosacral radicular pain (LRP). MATERIALS AND METHODS: In this prospective, double-blind, randomized study, 68 patients were randomly allocated to two groups: a 6-minute group, in which PRF was applied at 42 °C for 2 minutes followed by a 2-minute pause, repeated three times; and a 12-minute group, with a continuous application at 42 °C for 12 minutes. The total application time in each group was equal. After PRF, 2 to 3 mL of 1% lidocaine with 5 mg of dexamethasone was injected. The primary outcome was the intensity of leg pain measured using a numerical rating scale (NRS) three months after the procedure. The secondary outcomes were intensities of leg and back pain, the Oswestry Disability Index (ODI), the Medication Quantification Scale III (MQS), the Global Perceived Effect of Satisfaction (GPES), and the incidence of adverse events during follow-up. Primary and secondary outcomes were analyzed using a linear mixed-effect model in the modified intention-to-treat population. RESULTS: Each group comprised 34 patients. Three patients in each group did not receive the allocated intervention owing to alleviation of pain. The estimated NRS mean of leg pain at three months was 4.0 (95% CI, 3.2-4.9) and 4.5 (95% CI, 3.6-5.4) in the 6- and 12-minute groups, respectively, with no significant difference between groups (estimated mean difference, -0.5; 95% CI, -1.8 to 0.8; p = 0.436). Regarding the intensities of leg and back pain, ODI, MQS, and GPES, there was no significant difference between the two groups except for GPES at six months. No adverse events were observed in the groups. CONCLUSIONS: Among patients with chronic LRP, a prolonged PRF application of 12 minutes, compared with 6 minutes, caused no significant difference in leg pain intensity. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number under the Clinical Trial Registry of Korea for the study is KCT0003850; https://cris.nih.go.kr.

Innovative approaches in the treatment of chronic plantar fasciitis: comparison of pulsed radiofrequency ablation and surgical intervention.

PURPOSE: This study aimed to compare the effectiveness of Pulsed Radiofrequency Ablation (PRFA) and surgery for treating chronic plantar fasciitis, focusing on pain relief and functional outcomes. METHODS: A prospective study involved 30 patients with chronic plantar fasciitis unresponsive to 12 months of conservative treatment. Patients were divided into PRFA (n = 17) and surgical (n = 13) groups. Clinical evaluations were conducted preoperatively and at three, six and 12 months postoperatively using VAS, AOFAS, FFI, and RMS scores. Radiological measurements assessed foot structure impact. RESULTS: Both PRFA and surgery significantly reduced pain and improved function. PRFA had a shorter operative time and quicker return to activities (p < 0.001). At 3 months, PRFA showed superior VAS, FFI, and RMS scores (p < 0.05). Long-term outcomes were similar. No major complications occurred, but minor complications were higher in the surgical group (p < 0.01). CONCLUSIONS: PRFA is a minimally invasive, effective treatment for chronic plantar fasciitis with quicker recovery and lower complication rates compared to surgery. Both treatments offer comparable long-term benefits. Further studies are needed to confirm these findings.

Intramuscular Pulsed Radiofrequency Upregulates BNDF-TrKB Expression in the Spinal Cord in Rats as an Alternative Treatment for Complicated Pain.

Two cases of complicated pain exist: posterior screw fixation and myofascial pain. Intramuscular pulsed radiofrequency (PRF) may be an alternative treatment for such patients. This is a two-stage animal study. In the first stage, two muscle groups and two nerve groups were subdivided into a high-temperature group with PRF at 58 °C and a regular temperature with PRF at 42 °C in rats. In the second stage, two nerve injury groups were subdivided into nerve injury with PRF 42 °C on the sciatic nerve and muscle. Blood and spinal cord samples were collected. In the first stage, the immunohistochemical analysis showed that PRF upregulated brain-derived neurotrophic factor (BDNF) in the spinal cord in both groups of rats. In the second stage, the immunohistochemical analysis showed significant BDNF and tropomyosin receptor kinase B (TrkB) expression within the spinal cord after PRF in muscles and nerves after nerve injury. The blood biomarkers showed a significant increase in BDNF levels. PRF in the muscle in rats could upregulate BDNF-TrkB in the spinal cord, similar to PRF on the sciatica nerve for pain relief in rats. PRF could be considered clinically for patients with complicated pain and this study also demonstrated the role of BDNF in pain modulation. The optimal temperature for PRF was 42 °C.

Pulsed Radiofrequency of the Auriculotemporal Nerve to Reduce the Intensity of Tinnitus.

INTRODUCTION: Stimulation of the nonauditory nervous systems via the trigeminal nerve pathways can be a promising intervention for patients with tinnitus refractory to medical, conservative, and other treatment options. Therapy of the mandibular division of the trigeminal nerve through the auriculotemporal nerve has been reported as useful for patients with tinnitus. OBJECTIVES: The objective of our study was to study the long-term effects of pulsed radiofrequency of the auriculotemporal nerve in a large group of tinnitus sufferers and to find predictors for a prosperous result. DESIGN: A monocenter backward-looking group study. RESULTS: In a two-year period, 67 tinnitus patients had pulsed radiofrequency of the auriculotemporal nerve. Twentythree (35%) reported reduced tinnitus loudness at the 7-week post-treatment follow-up. These patients valued the improvements as: 61% good, 22% moderate, and 17% slight. In 3% of patients, tinnitus magnified after the treatment. The odds of permanent tinnitus relief after successful pulsed radiofrequency of the auriculotemporal nerve are 68% at 1 year postoperative. In tinnitus patients without cervical pain 62% had an improvement following pulsed radiofrequency of the auriculotemporal nerve compared to 28% in those not fulfilling this criterion (p=0.024). CONCLUSIONS: Neuromodulation of the auriculotemporal nerve is an uncomplicated remedy for tinnitus. In a select group of tinnitus patients this treatment can a good relief of their tinnitus for a long period. Especially, tinnitus sufferers without cervical pain will benefit of this therapy.

A narrative review of pulsed radiofrequency for the treatment of carpal tunnel syndrome.

OBJECTIVE: Carpal tunnel syndrome (CTS), which is the most common peripheral nerve entrapment syndrome, can commonly persist despite conservative treatment modalities such as wrist splinting or medications. Pulsed radiofrequency represents a minimally invasive pain intervention technique to alleviate pain. The literature was reviewed to establish the effectiveness of PRF therapy for CTS. STUDY DESIGN: This is a narrative review of relevant articles on the effectiveness of PRF for CTS. METHOD: Four databases, MEDLINE, Cochrane Central Register of Controlled Trials, Embase, OVID Emcare, and Web of Science, were systematically searched. 804 records were screened, and the reference lists of eligible articles were examined. For this review, eight extracted studies were narratively explored. RESULTS: One case report, three retrospective cohorts, one observational prospective study, and three randomized-controlled trials were included. PRF likely provides both an analgesic and functional benefit in patients with mild to severe CTS, and it also shows benefit as an adjunct to carpal tunnel release surgery. Long-term data is limited. It also appears likely that steroid injection may represent a comparable treatment modality to PRF, and there have been positive results when these modalities are used together. Notably, all studies differed in their methodology, making direct comparisons between studies challenging. CONCLUSIONS: The evidence for PRF in the treatment of CTS, across the range of spectrum of severity or peri-operative to CTS surgery, appears favorable and avoids known side effects of steroid injections. Potential mechanisms for PRF and future directions for research are explored.

Pulsed radiofrequency or surgery for anterior cutaneous nerve entrapment syndrome: Long-term results of a randomized controlled trial.

PURPOSE: Patients with anterior cutaneous nerve entrapment syndrome (ACNES) often require a step-up treatment strategy including abdominal wall injections, pulsed radiofrequency (PRF) or a neurectomy. Long-term success rates of PRF and surgery are largely unknown. The aim of the current study was to report on the long-term efficacy of PRF and neurectomy in ACNES patients who earlier participated in the randomized controlled PULSE trial. METHODS: Patients who completed the PULSE trial were contacted about pain status and additional treatments in the following years. Treatment success was based on numerical rating scale (NRS) following IMMPACT recommendations and Patient Global Impression of Change (PGIC) scores. RESULTS: A total of 44 of the original 60 patients were eligible for analysis (73.3%). Median follow-up was 71.5 months. One patient (4.3%) was still free of pain after a single PRF session, and five additional patients (21.7%) were free of pain by repetitive PRF treatments. By contrast, 13 patients (61.9%) in the neurectomy group were still free of pain without additional treatments. All pain recurrences and therefore primary re-interventions occurred in the first 2 years after the initial treatment. CONCLUSION: Approximately one in five ACNES patients undergoing PRF treatment reports long-term success obviating the need of surgical intervention. Surgery for ACNES is long-term effective in approximately two of three operated patients. Recurrent ACNES beyond 2 years after either intervention is rare.

1. Lumbosacral radicular pain.

INTRODUCTION: Patients suffering lumbosacral radicular pain report radiating pain in one or more lumbar or sacral dermatomes. In the general population, low back pain with leg pain extending below the knee has an annual prevalence that varies from 9.9% to 25%. METHODS: The literature on the diagnosis and treatment of lumbosacral radicular pain was reviewed and summarized. RESULTS: Although a patient's history, the pain distribution pattern, and clinical examination may yield a presumptive diagnosis of lumbosacral radicular pain, additional clinical tests may be required. Medical imaging studies can demonstrate or exclude specific underlying pathologies and identify nerve root irritation, while selective diagnostic nerve root blocks can be used to confirm the affected level(s). In subacute lumbosacral radicular pain, transforaminal corticosteroid administration provides short-term pain relief and improves mobility. In chronic lumbosacral radicular pain, pulsed radiofrequency (PRF) treatment adjacent to the spinal ganglion (DRG) can provide pain relief for a longer period in well-selected patients. In cases of refractory pain, epidural adhesiolysis and spinal cord stimulation can be considered in experienced centers. CONCLUSIONS: The diagnosis of lumbosacral radicular pain is based on a combination of history, clinical examination, and additional investigations. Epidural steroids can be considered for subacute lumbosacral radicular pain. In chronic lumbosacral radicular pain, PRF adjacent to the DRG is recommended. SCS and epidural adhesiolysis can be considered for cases of refractory pain in specialized centers.

Pulsed radiofrequency of lumbar dorsal root ganglion for lumbar radicular pain: A systematic review and meta-analysis.

BACKGROUND: Pulsed radiofrequency (PRF) of the lumbar dorsal root ganglion (DRG) has been widely used as a method to relieve lumbar radicular pain (LRP). However, the value of PRF application in LRP patients remains uncertain. This systematic review aimed to compare the effects of PRF of lumbar DRG and LEI in patients with LRP. METHODS: A literature search was performed using well-known databases for articles published up to May 2023. We included randomized controlled trials (RCTs) that evaluated the effects of PRF compared to LEI with or without steroids. We screened articles, extracted data, and assessed risk of bias in duplicate. The pain scores and Oswestry Disability Index (ODI) scores at 1, 3, and 6 months after procedures were obtained. A random-effects meta-analysis model was applied for outcomes. We evaluated evidence certainty for each outcome using the GRADE scoring system. This review was registered in the PROSPERO (ID: CRD42021253628). RESULTS: A total of 10 RCTs were included and data of 613 patients were retrieved. We assessed the overall quality of the evidence as very low to moderate. PRF showed no difference in pain scores at 1 (mean difference [MD] -0.80, 95% confidence interval [CI] -1.59 to 0.00, low certainty) and 6 months (MD -2.37, 95% CI -4.79 to 0.05, very low certainty), and significantly improved pain scores at 3 months (MD -1.31, 95% CI -2.29 to -0.33, low certainty). There was no significant difference in ODI score at any interval (very low to low certainty). In the subgroup who underwent a diagnostic block, did not use steroids, and PRF duration greater than 360 s, PRF significantly reduced pain scores at 3 months after procedures. CONCLUSIONS: We found low quality of the evidence supporting adjuvant PRF to the lumbar DRG has a greater analgesic effect at 3 months after procedures in patients with LRP than LEI. We identified no convincing evidence to show that this treatment improves function. High-quality evidence is lacking, and data were largely derived from short-term effects. Given these limitations, high-quality trials with data on long-term effects are needed.

Radiofrequency for chronic lumbosacral and cervical pain: Results of a consensus study using the RAND/UCLA appropriateness method.

BACKGROUND: Despite the routine use of radiofrequency (RF) for the treatment of chronic pain in the lumbosacral and cervical region, there remains uncertainty on the most appropriate patient selection criteria. This study aimed to develop appropriateness criteria for RF in relation to relevant patient characteristics, considering RF ablation (RFA) for the treatment of chronic axial pain and pulsed RF (PRF) for the treatment of chronic radicular pain. METHODS: The RAND/UCLA Appropriateness Method (RUAM) was used to explore the opinions of a multidisciplinary European panel on the appropriateness of RFA and PRF for a variety of clinical scenarios. Depending on the type of pain (axial or radicular), the expert panel rated the appropriateness of RFA and PRF for a total of 219 clinical scenarios. RESULTS: For axial pain in the lumbosacral or cervical region, appropriateness of RFA was determined by the dominant pain trigger and location of tenderness on palpation with higher appropriateness scores if these variables were suggestive of the diagnosis of facet or sacroiliac joint pain. Although the opinions on the appropriateness of PRF for lumbosacral and cervical radicular pain were fairly dispersed, there was agreement that PRF is an appropriate option for well-selected patients with radicular pain due to herniated disc or foraminal stenosis, particularly in the absence of motor deficits. The panel outcomes were embedded in an educational e-health tool that also covers the psychosocial aspects of chronic pain, providing integrated recommendations on the appropriate use of (P)RF interventions for the treatment of chronic axial and radicular pain in the lumbosacral and cervical region. CONCLUSIONS: A multidisciplinary European expert panel established patient-specific recommendations that may support the (pre)selection of patients with chronic axial and radicular pain in the lumbosacral and cervical region for either RFA or PRF (accessible via https://rftool.org). Future studies should validate these recommendations by determining their predictive value for the outcomes of (P)RF interventions.

Comparative evaluation of functional outcome and pain relief after pulsed radiofrequency of the saphenous nerve within and distal to the adductor canal in medial compartment knee osteoarthritis: A randomized double-blind trial.

Background and Aims: Pulsed radiofrequency (PRF) of the saphenous nerve (SN) has shown effective pain relief in knee pain because of knee osteoarthritis (KOA). The adductor canal (AC) contains other sensory nerves innervating the medial part of the knee joint apart from SN. We compared the PRF of SN within and outside the AC for their quality and duration of pain relief in knee osteoarthritis of the medial compartment (KOA-MC). Material and Methods: We conducted a randomized prospective study in 60 patients with anteromedial knee pain because of KOA-MC. Patients in group A received PRF-SN, and those in group B received PRF-AC. The primary objectives were comparison of pain by Visual Analog Scale (VAS) scores and changes in quality of daily living by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and OXFORD knee scores. The secondary objectives were comparison of analgesic requirements using Medicine Quantification Scale (MQS) scores and block-related complications. Intra-group comparison was performed by analysis of variance. Inter-group normally distributed data were assessed by Student's t-test, non-normally distributed and ordinal data were assessed by Mann-Whitney U-test, and categorical data were assessed by Chi-square test. A P value of <0.05 was considered significant. Results: VAS scores were significantly lower in Gr-B at 12 weeks. The WOMAC scores and OXFORD scores at 4, 8, 12, and 24 weeks were significantly lower in Gr-B compared to Gr-A. Conclusion: The PRF-AC provides better pain relief and functional outcome than PRF-SN; however, duration of pain relief was not significantly different.

Ultrasound-guided dry needling of masticatory muscles in trigeminal neuralgia - A case series of 35 patients.

Background: Trigeminal neuralgia (TGN) is considered a sensory neuropathy. However, reports of pain on chewing/speaking suggest a masticatory myofascial involvement. Objective: To examine the effect of ultrasound-guided dry needling (USGDN), which deactivates myofascial trigger points in masticatory, neck, and facial muscles on TGN symptoms. Methods: Charts of 35 patients treated for TGN were retrospectively reviewed. Treatment was USGDN alone or combined with trigeminal ganglion/mandibular nerve pulsed radiofrequency (PRF), followed by yoga mudras to stretch masticatory and facial muscles. Patients were followed for 1-8 years. Outcome parameters were reduction of medications with reduction in neuralgic attack frequency and Numeric Rating Scale (NRS) score. Results: 23 patients (65.7%) received USGDN alone, 12 patients (34.3%) received PRF treatment before USGDN. A significant reduction in the mean (SD) NRS (5.7 [1.2] vs 8.8 [1.6]; P < .001) and neuralgic attack frequency (47 [27] vs 118 [70] attacks/day; P < .001) was seen after PRF compared with baseline, respectively. Following USGDN, the mean (SD) NRS further decreased significantly to 1.0 (0.9) (P < .001). USGDN alone produced a similar improvement in the NRS (8.9 [1.5] at baseline reduced to 0.6 [0.7] post-USGDN; P < .001). Patients in both groups reported a cessation in neuralgic attacks after USGDN. Post-USGDN, 18/27 patients completely discontinued medication, with the mean (SD) carbamazepine dose significantly reducing from 716.7 (260.9) mg/day at baseline to 113.0 (250.2) mg/day post-USGDN (P < .001). Conclusion: Decisive relief of TGN by USGDN suggests neuromyalgia involving masticatory muscles. Prospective, controlled studies could confirm these findings.

Changes in TRPV1 Receptor, CGRP, and BDNF Expression in Rat Dorsal Root Ganglion with Resiniferatoxin-Induced Neuropathic Pain: Modulation by Pulsed Radiofrequency Applied to the Sciatic Nerve.

Pulsed radiofrequency (PRF) is a safe method of treating neuropathic pain by generating intermittent electric fields at the needle tip. Resiniferatoxin (RTX) is an ultrapotent agonist of transient receptor potential vanilloid subtype-1 (TRPV1) receptors. We investigated the mechanism of PRF using a rat model of RTX-induced neuropathic pain. After administering RTX intraperitoneally, PRF was applied to the right sciatic nerve. We observed the changes in TRPV1, calcitonin gene-related peptide (CGRP), and brain-derived neurotrophic factor (BDNF) in the dorsal root ganglia by western blotting. Expressions of TRPV1 and CGRP were significantly lower in the contralateral (RTX-treated, PRF-untreated) tissue than in control rats (p<0.0001 and p<0.0001, respectively) and the ipsilateral tissues (p<0.0001 and p<0.0001, respectively). BDNF levels were significantly higher in the contralateral tissues than in the control rats (p<0.0001) and the ipsilateral tissues (p<0.0001). These results suggest that, while TRPV1 and CGRP are decreased by RTX-induced neuronal damage, increased BDNF levels result in pain development. PRF may promote recovery from neuronal damage with concomitant restoration of TRPV1 and CGRP, and exert its analgesic effect by reversing BDNF increase. Further research is required to understand the role of TRPV1 and CGRP restoration in improving mechanical allodynia.

Efficacy of Long-Term Spinal Nerve Posterior Ramus Pulsed Radiofrequency in Treating Subacute Herpetic Neuralgia: A Prospective Randomized Controlled Trial.

OBJECTIVE: This study aimed to observe the clinical efficacy of long-term spinal nerve posterior ramus pulsed radiofrequency (PRF) in treating subacute herpes zoster neuralgia (HZN). METHODS: A total of 120 patients with subacute HZN in the thoracolumbar region and back were equally randomized to the conventional PRF group (P group, n = 60), with a pulse of 180 s, or to the long-term PRF group (LP group, n = 60), with a pulse of 600 s. The patients' baseline characteristics, the incidence rate of postherpetic neuralgia (PHN), and the dose of analgesics were compared between the two groups. RESULTS: Based on the pain-rating index (PRI), the PRI-sensory, PRI-affective, visual analogue scale, and present pain intensity scores in the two groups were lower at T2, T3, and T4 time points than at the T1 time point after treatment (p < 0.05). After 2 months, the dose of analgesics was significantly lower in the LP group than in the P group (p < 0.05), and the incidence of PHN was considerably lower. CONCLUSIONS: Long-term spinal nerve posterior ramus PRF is a more effective treatment strategy for subacute HZN than conventional PRF. It can effectively prevent the occurrence of PHN.

Novel Bipolar High-Voltage Pulsed Radiofrequency Targeting the Cervical Sympathetic Chain for Treating Acute Herpetic Neuralgia.

INTRODUCTION: Postherpetic neuralgia (PHN) in the oral, maxillofacial, neck, and upper limb regions is a refractory neuropathic pain and severely affects the quality of life of patients. Because of the absence of ideal treatments for this condition, relieving pain in the acute stage and preventing the occurrence of PHN are of great clinical significance. However, the optimal intervention for this acute herpetic neuralgia remains obscure. OBJECTIVES: This study aimed to investigate whether bipolar high-voltage pulsed radiofrequency (PRF) targeting the cervical sympathetic chain could effectively treat acute herpetic neuralgia in the oral, maxillofacial, neck, and upper limb regions and reduce the incidence of PHN. MATERIALS AND METHODS: A total of 60 patients with acute herpetic neuralgia in the oral, maxillofacial, neck, and upper limb regions were enrolled. The radiofrequency group (n = 30) received bipolar high-voltage PRF under ultrasound guidance at the level of the transverse processes of C6 and C7 to modulate the cervical sympathetic chain. In the sham group (n = 30), the electrodes were simply placed at the same position as in the radiofrequency group, but no radiofrequency energy was applied. The same treatment was repeated in each group after 72 hours. If patients were reported to have a visual analog scale (VAS) score ≥4, they would receive oral tramadol and gabapentin as rescue analgesics. The VAS score, Pittsburgh Sleep Quality Index (PSQI), 36-Item Short Form Health Survey (SF-36) score, use of tramadol and gabapentin, incidence of PHN, and adverse reactions were recorded to assess the effect and safety of therapy during three months of follow-up. RESULTS: Decreased VAS scores, PSQI scores, and improved SF-36 scores were detected in the two groups at different time points after treatment (all p < 0.05). The VAS scores, PSQI scores, use of tramadol and gabapentin, and incidence of PHN were significantly lower, whereas the SF-36 scores were significantly higher in the radiofrequency group than in the Sham group (all p < 0.05). No serious adverseness related to the treatment was detected in either group. CONCLUSIONS: Bipolar high-voltage PRF treatment targeting the cervical sympathetic chain could effectively relieve acute herpetic neuralgia in the oral, maxillofacial, neck, and upper limb regions and reduce PHN incidence. The efficacy and safety of this novel treatment make it worthy of recommendation for clinical application.

Effectiveness and safety of high-voltage pulsed radiofrequency to treat patients with primary trigeminal neuralgia: a multicenter, randomized, double-blind, controlled study.

BACKGROUND: Trigeminal neuralgia (TN) is a debilitating pain disorder that still lacks an ideal treatment option. Pulsed radiofrequency (PRF), especially with high output voltage, is a novel and minimally invasive technique. PRF is regarded a promising treatment option for TN patients who respond poorly to medical treatment; however, the available evidence still lacks high quality randomized controlled trials (RCTs). Our study aimed to evaluate the long-term (1 year and 2 years) effects and safety of high-voltage PRF in primary TN patients and provide stronger evidence for TN treatment options. METHODS: We performed a multicenter, double-blind, RCT in adults (aged 18-75 years) with primary TN who responded poorly to drug therapy or were unable to tolerate the side effects of drug. Eligible participants were randomly assigned (1:1) to receive either high voltage PRF or nerve block with steroid and local anesthetic drugs. The primary endpoint was the 1-year response rate. This trial has been registered in the clinicaltrials.gov website (registration number: NCT03131466). RESULTS: One hundred and sixty-two patients were screened for enrollment between April 28th,2017 and September1st, 2019, among whom, 28 were excluded. One hundred and thirty-four participants were randomly assigned to either receive high voltage PRF (n = 67) or nerve block (n = 67). The proportion of patients with a positive response at 1-year after the procedure in the PRF group was significantly higher than that in the nerve block group in the intention-to-treat population (73.1% vs. 32.8%, p < 0.001). There was no difference between groups in the incidence of adverse events. CONCLUSIONS: Our findings support that high voltage PRF could be a preferred interventional choice prior to receiving more invasive surgical treatment or neuro-destructive treatment for TN patients who have poor responses to medical treatment. TRIAL REGISTRATION: Our study has been registered at ClinicalTrials.gov (trial registration number: NCT03131466).

2. Cervical radicular pain.

INTRODUCTION: Cervical radicular pain is pain perceived in the upper limb, caused by irritation or compression of a cervical spine nerve, the roots of the nerve, or both. METHODS: The literature on the diagnosis and treatment of cervical radicular pain was retrieved and summarized. RESULTS: The diagnosis is made by combining elements from the patient's history, physical examination, and supplementary tests. The Spurling and shoulder abduction tests are the two most common examinations used to identify cervical radicular pain. MRI without contrast, CT scanning, and in some cases plain radiography can all be appropriate imaging techniques for nontraumatic cervical radiculopathy. MRI is recommended prior to interventional treatments. Exercise with or without other treatments can be beneficial. There is scant evidence for the use of paracetamol, nonsteroidal anti-inflammatory drugs, and neuropathic pain medications such as gabapentin, pregabalin, tricyclic antidepressants, and anticonvulsants for the treatment of radicular pain. Acute and subacute cervical radicular pain may respond well to epidural corticosteroid administration, preferentially using an interlaminar approach. By contrast, for chronic cervical radicular pain, the efficacy of epidural corticosteroid administration is limited. In these patients, pulsed radiofrequency treatment adjacent to the dorsal root ganglion may be considered. CONCLUSIONS: There is currently no gold standard for the diagnosis of cervical radicular pain. There is scant evidence for the use of medication. Epidural corticosteroid injection and pulsed radiofrequency adjacent to the dorsal root ganglion may be considered. [Correction added on 12 June 2023, after first online publication: The preceding sentence was corrected.].

Interventional pathway in the management of refractory chronic flank pain: Prospective series in 45 patients.

BACKGROUND: Chronic flank pain can pose a therapeutic challenge. Current management centres on visceral pathology affecting the renal system. Acute exacerbations can be severe, requiring emergency admission. Patients usually have well-established visceral pathology including polycystic kidney disease, Fowler's syndrome, and renal calculi disease that often cause recurrent urinary tract infections. However, in many cases, despite negative investigations including imaging, biochemistry and urine analysis, flank pain persists. Abdominal myofascial pain syndrome is a poorly recognized pathology in this cohort. The report describes the underlying pathophysiology and a novel interventional management pathway for patients presenting with refractory flank pain secondary to abdominal myofascial pain syndrome. METHODS: Adult patients with refractory chronic flank pain at a tertiary renal unit were included as a part of an on-going prospective longitudinal audit. Patients refractory to standard management were offered the interventional pathway. The pathway included two interventions: quadratus lumborum block with steroid and pulsed radio frequency treatment. Patients completed brief pain inventory and hospital anxiety and depression scale questionnaires at baseline, 3 and 6 months postprocedure. Outcomes collected included ability to maintain employment, change in opioid consumption at 6 months and impact on emergency hospital admissions at 12 months after initiation of the pathway. RESULTS: Forty-five patients were referred to the pain medicine clinic over a seven-year period between 2014 and 2021. All patients were offered the interventions. Four patients refused due to needle phobia. Forty-one patients received transmuscular quadratus lumborum plane block with steroids. Twenty-seven patients (27/41, 66%) reported durable benefit at 6 months and six patients (6/41, 15%) had clinically significant relief at 3 months. Fifteen patients received pulsed radiofrequency to quadratus lumborum plane and 11 patients (73%) reported > 50% analgesia at 6 months. Treatment failure rate was 10% (4/41). Opioid consumption at 6 months and emergency admission at 12 months were reduced post intervention. CONCLUSION: Abdominal myofascial pain syndrome is a poorly recognized cause of chronic flank pain syndrome. The interventional management pathway could be an effective solution in this cohort.

Extracellular signal-regulated kinase phosphorylation enhancement and NaV1.7 sodium channel upregulation in rat dorsal root ganglia neurons contribute to resiniferatoxin-induced neuropathic pain: The efficacy and mechanism of pulsed radiofrequency therapy.

Pulsed radiofrequency (PRF) therapy is one of the most common treatment options for neuropathic pain, albeit the underlying mechanism has not been hitherto elucidated. In this study, we investigated the efficacy and mechanism of PRF therapy on resiniferatoxin (RTX)-induced mechanical allodynia, which has been used as a model of postherpetic neuralgia (PHN). Adult male rats were intraperitoneally injected with a vehicle or RTX. Furthermore, PRF current was applied on a unilateral sciatic nerve in all RTX-treated rats. On both ipsilateral and contralateral sides, the paw mechanical withdrawal thresholds were examined and L4-6 dorsal root ganglia (DRG) were harvested. In the DRG of rats with RTX-induced mechanical allodynia, NaV1.7, a voltage-gated Na+ channel, was upregulated following the enhancement of extracellular signal-regulated kinase phosphorylation. Early PRF therapy, which was applied 1 week after RTX exposure, suppressed this NaV1.7 upregulation and showed an anti-allodynic effect; however, late PRF therapy, which was applied after 5 weeks of RTX exposure, failed to inhibit allodynia. Interestingly, late PRF therapy became effective after daily tramadol administration for 7 days, starting from 2 weeks after RTX exposure. Both early PRF therapy and late PRF therapy combined with early tramadol treatment suppressed NaV1.7 upregulation in the DRG of rats with RTX-induced mechanical allodynia. Therefore, NaV1.7 upregulation in DRG is related to the development of RTX-induced neuropathic pain; moreover, PRF therapy may be effective in the clinical management of patients with PHN via NaV1.7 upregulation inhibition.