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.

Comprehensive Comparison of Therapeutic Efficacy of Radiofrequency Thermocoagulation and Pulsed Radiofrequency in Treatment of Elderly Patients with Thoracic Postherpetic Neuralgia.

BACKGROUND We comprehensively compared the therapeutic efficacy of radiofrequency thermocoagulation (RFT) and pulsed radiofrequency (PRF) in the treatment of elderly patients with thoracic postherpetic neuralgia (PHN). MATERIAL AND METHODS We divided 149 elderly patients with thoracic PHN into 2 groups - the RFT group (n=79) and the PRF group (n=70) - based on the radiofrequency mode administered. The Visual Analog Scale (VAS), Athens Insomnia Scale (AIS), Generalized Anxiety Disorder 7 items (GAD-7), and Patient Health Questionnaire 9 items (PHQ-9) were used to analyze the degree of pain, sleep quality, and psychological state of patients before and 1 week, 1 month, 3 months, 6 months, and 12 months after treatment. RESULTS VAS, AIS, GAD-7, and PHQ-9 scores were significantly decreased after RFT and PRF treatment (P<0.001). There was no significant difference in VAS scores between the 2 groups at 1 week and 1 month after treatment (P>0.05). Then, VAS scores in the RFT group were significantly lower than those in the PRF group at 3, 6, and 12 months after treatment (P<0.001). At 1 week after treatment, there were no significant differences in AIS, GAD-7, and PHQ-9 scores between the 2 groups (P>0.05). However, the RFT group had significantly lower AIS, GAD-7, and PHQ-9 scores than the PRF group at 1, 3, 6, and 12 months after treatment (P<0.05). CONCLUSIONS RFT and PRF both effectively reduced pain in the distribution area of thoracic spinal neuropathy and improved the sleep quality and psychological state of elderly patients with thoracic PHN, but RFT had a better long-term effect.

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.

Pulsed Radiofrequency of the Auricular Branch of the Vagal Nerve in Tinnitus Patients.

INTRODUCTION: Pulsed radiofrequency of the auricular branch of the vagal nerve has strongly reduced tinnitus in a person with violent tinnitus and severe cervical pain. OBJECTIVES: The objective of our study was to study the long-term effects of pulsed radiofrequency of the auricular branch of the vagal nerve in a large group of tinnitus sufferers and to find predictors for a prosperous result. DESIGN: A monocenter backward-looking group study. RESULTS: 48% of tinnitus sufferers who undertook pulsed radiofrequency of the auricular branch of the vagal nerve reported a reduced loudness of their tinnitus, which was qualified as being moderate to good in 87% of these patients. The reduction exceeded mostly 1 year. An angle smaller than 3 degrees between the 2nd and 3rd cervical vertebrae on lateral radiograph predicted a better outcome of this therapy. CONCLUSION: Neuromodulation of the auricular branch of the vagal nerve is an uncomplicated remedy for tinnitus, especially for tinnitus patients with a pathologically small C2-C3 angle.

Clinical study of puncture technique in single division of the trigeminal ganglion intumescentia.

OBJECTIVE: We explored the feasibility of single-division puncture in the ophthalmic division, maxillary division, and mandibular division of the trigeminal ganglion intumescentia (TGI) and the feasibility of radiofrequency treatment of trigeminal neuralgia. METHODS: According to the previous anatomical image studies, 3D Slicer software was used to analyze the CT images of the patients. The trigeminal ganglion fossa (TGF) was used as the imaging sign. TGI was identified in the sagittal plane along the fiber. The puncture path starts from the TGI center-foramen ovale line, extending outward to the epidermis as the needle insertion point, and extending inward to the division boundary. For lateral puncture, which is blocked by the mandible, the positions of closed mouth, open mouth, and over-open mouth were used. Multiple targets were generated using straight electrodes and curved electrodes to achieve full coverage of TGI. According to the preoperative design, general anesthesia surgery was performed. Xper CT was used for imaging, and the puncture was guided by Xper Guide. Radiofrequency treatment of TGI was conducted. RESULTS: In total, 45 patients with trigeminal neuralgia underwent 50 single-division TGI punctures. The procedure was smooth and the compliance with the design was good. Continuous radiofrequency (CRF) was performed, the VAS scores were 25 times at 70°C, 19 times at 65°C, two times at 60°C, and two times at 50°C (both in the ophthalmic division). Pulsed radiofrequency (PRF) was conducted two times. Within 24 h after the procedure, the VAS scores were all 0. From 1 to 7 days after the procedure, pain recurrence was found in three cases, of whom two cases received pulsed radiofrequency treatment. Patients were followed up for 1-24 months and there were no recurrence. After continuous radiofrequency at 65-70°C, the moderate tactile loss was observed, and nearly half of the patients had food residues on the surgical side after 6 months. After continuous radiofrequency at 60°C, there was mild tactile loss and no food residue. The tactile sensation was slightly decreased after continuous radiofrequency at 50°C, and the tactile sensation was normal the next day. CONCLUSION: Trigeminal ganglion intumescentia single-division radiofrequency is effective and feasible for the treatment of trigeminal neuralgia.

Comparison of Two Different Pulsed Radiofrequency Modes for Prevention of Postherpetic Neuralgia in Elderly Patients With Acute/Subacute Trigeminal Herpes Zoster.

OBJECTIVE: Trigeminal postherpetic neuralgia (PHN) is often refractory to treatment. Pulsed radiofrequency (PRF) neuromodulation can help in preventing PHN after herpes zoster. This study aimed to compare the efficacy and safety of two different PRF modes on gasserian ganglion neuromodulation in elderly patients with acute/subacute trigeminal herpes zoster. MATERIALS AND METHODS: A total of 120 elderly patients with acute or subacute (within past three months) trigeminal herpes zoster were randomized to receive either a single cycle of high-voltage, long-duration PRF (HL-PRF group; N = 60) or three cycles of standard PRF (S-PRF group; N = 60). Patients were followed up for six months after treatment. Visual analog scale (VAS) pain score, 36-Item Short Form Health Survey (SF-36) score, and pregabalin at baseline and at different time points during follow-up were recorded. RESULTS: VAS and SF-36 scores declined significantly from baseline levels in both groups (p < 0.001). The scores were significantly lower in the HL-PRF group than in the S-PRF group at some time points (p < 0.05). The mean dose of pregabalin was significantly lower in the HL-PRF group than in the S-PRF group on days 3, 14, and 28 after treatment (p < 0.05). No serious adverse events occurred in either group. CONCLUSION: HL-PRF neuromodulation of the gasserian ganglion appears to be more effective than S-PRF for preventing PHN in the elderly. CLINICAL TRIAL REGISTRATION: ChiCTR2000038775.

The Mechanism of Action between Pulsed Radiofrequency and Orthobiologics: Is There a Synergistic Effect?

Radiofrequency energy is a common treatment modality for chronic pain. While there are different forms of radiofrequency-based therapeutics, the common concept is the generation of an electromagnetic field in the applied area, that can result in neuromodulation (pulsed radiofrequency-PRF) or ablation. Our specific focus relates to PRF due to the possibility of modulation that is in accordance with the mechanisms of action of orthobiologics. The proposed mechanism of action of PRF pertaining to pain relief relies on a decrease in pro-inflammatory cytokines, an increase in cytosolic calcium concentration, a general effect on the immune system, and a reduction in the formation of free radical molecules. The primary known properties of orthobiologics constitute the release of growth factors, a stimulus for endogenous repair, analgesia, and improvement of the function of the injured area. In this review, we described the mechanism of action of both treatments and pertinent scientific references to the use of the combination of PRF and orthobiologics. Our hypothesis is a synergic effect with the combination of both techniques which could benefit patients and improve the life quality.

Comparison of Pulsed Radiofrequency, Oxygen-Ozone Therapy and Epidural Steroid Injections for the Treatment of Chronic Unilateral Radicular Syndrome.

Background and objectives: For the treatment of chronic unilateral radicular syndrome, there are various methods including three minimally invasive computed tomography (CT)-guided methods, namely, pulsed radiofrequency (PRF), transforaminal oxygen ozone therapy (TFOOT), and transforaminal epidural steroid injection (TFESI). Despite this, it is still unclear which of these methods is the best in terms of pain reduction and disability improvement. Therefore, the purpose of this study was to evaluate the short and long-term effectiveness of these methods by measuring pain relief using the visual analogue scale (VAS) and improvement in disability (per the Oswestry disability index (ODI)) in patients with chronic unilateral radicular syndrome at L5 or S1 that do not respond to conservative treatment. Materials and Methods: After screening 692 patients, we enrolled 178 subjects, each of whom underwent one of the above CT-guided procedures. The PRF settings were as follows: pulse width = 20 ms, f = 2 Hz, U = 45 V, Z ˂ 500 Ω, and interval = 2 × 120 s. For TFOOT, an injection of 4-5 mL of an O2-O3 mixture (24 µg/mL) was administered. For the TFESI, 1 mL of a corticosteroid (betamethasone dipropionate), 3 mL of an anaesthetic (bupivacaine hydrochloride), and a 0.5 mL mixture of a non-ionic contrast agent (Iomeron 300) were administered. Pain intensity was assessed with a questionnaire. Results: The data from 178 patients (PRF, n = 57; TFOOT, n = 69; TFESI, n = 52) who submitted correctly completed questionnaires in the third month of the follow-up period were used for statistical analysis. The median pre-treatment visual analogue scale (VAS) score in all groups was six points. Immediately after treatment, the largest decrease in the median VAS score was observed in the TFESI group, with a score of 3.5 points (a decrease of 41.7%). In the PRF and TFOOT groups, the median VAS score decreased to 4 and 5 points (decreases of 33% and 16.7%, respectively). The difference in the early (immediately after) post-treatment VAS score between the TFESI and TFOOT groups was statistically significant (p = 0.0152). At the third and sixth months after treatment, the median VAS score was five points in all groups, without a statistically significant difference (p > 0.05). Additionally, there were no significant differences in the Oswestry disability index (ODI) values among the groups at any of the follow-up visits. Finally, there were no significant effects of age or body mass index (BMI) on both treatment outcomes (maximum absolute value of Spearman's rank correlation coefficient = 0.193). Conclusions: Although the three methods are equally efficient in reducing pain over the entire follow-up, we observed that TFESI (a corticosteroid with a local anaesthetic) proved to be the most effective method for early post-treatment pain relief.

Bipolar Pulsed Radiofrequency for Trigeminal Neuralgia: A Report of Two Cases.

BACKGROUND: Trigeminal neuralgia (TN) is the most common cause of facial pain, leading to significant disability and impacting a patient's quality of life. Percutaneous procedures like continuous radiofrequency, pulsed radiofrequency (PRF), and combined continuous and pulsed radiofrequency have been studied in past years comparing different voltages in order to find more effective therapies with fewer complications (eg, numbness and masseter muscle weakness). With regard to young patients, there is still insufficient evidence on the most appropriate procedure in this patient population. PRF does not cause thermal damage. The mechanism of action involves delivering an electrical field to targeted nerves or tissues, modulating pain. We propose that bipolar pulsed radiofrequency (2 parallel cannulas) in the trigeminal ganglion produce a denser and larger field resulting in more effective controlled pain. CASE PRESENTATION: We present 2 cases of 40- and 48-year-old men with severe V2 to V3 TN who underwent bipolar PRF. We performed bipolar PRF on the trigeminal ganglion through the foramen ovale using two 22-gauge 100-mm cannulas with 10-mm active tips. Parameters used were voltage of 85 V, pulse width of 20 milliseconds, and total duration time of 6 minutes. Both patients reported complete relief of pain after the procedure, and at 2-year follow-up they were pain free and experienced a better quality of life. No complications were reported. CONCLUSION: Bipolar PRF could be a non-neurodestructive option for young people with TN and deserves further investigation as a treatment option.

Use of Pulsed Radiofrequency for the Treatment of Discogenic Back Pain: A Narrative Review.

BACKGROUND: Low-back pain (LBP) is one of the most frequently reported symptoms of patients who visit pain clinics, and a significant proportion of them have discogenic pain. Pulsed radiofrequency (PRF) stimulation is an effective treatment for various types of pain. PURPOSE: We reviewed articles which investigated the effectiveness of intradiscal PRF for controlling discogenic LBP. METHODS AND MATERIALS: We searched PubMed for papers published prior to August 7, 2020, in which intradiscal PRF was used for treating discogenic LBP. The key search phrase was (intradiscal PRF) for identifying potentially relevant articles. We included articles in which intradiscal PRF was used for controlling LBP. Review articles were excluded. RESULTS: Nine publications were included in this review. Except for one study, all other studies showed positive therapeutic outcomes after treating discogenic LBP using intradiscal PRF. However, the quality of these studies was not high. CONCLUSIONS: This review showed that intradiscal PRF appears to be a helpful treatment method for patients with discogenic LBP. Our review provides insights into the degree of evidence of the therapeutic effects of intradiscal PRF for alleviating discogenic LBP. For confirmation of the effectiveness of intradiscal PRF on discogenic LBP, more high-quality studies are necessary.

Comparison of the Efficacy Between Intradiscal Gelified Ethanol (Discogel) Injection and Intradiscal Combination of Pulsed Radiofrequency and Gelified Ethanol (Discogel) Injection for Chronic Discogenic Low Back Pain Treatment. A Randomized Double-Blind Clinical Study.

OBJECTIVE: The aim of the present study was to compare two new techniques, intradiscal gelified ethanol injection (Discogel) and the combination of intradiscal pulsed radiofrequency and gelified ethanol injection (PRF+Discogel), regarding their efficacy in discogenic low back pain treatment. DESIGN: Randomized, double-blind, clinical study. METHODS: The final sample was randomized into group A (N = 18, D) and group B (N = 18, PRF+D). During the procedure, four patients from group B were excluded from the study. Groups A and B were assessed regarding the pain score (VAS 0-10), before the interventional procedures, and one, three, six, and 12 months after. Secondary objectives of the study were to compare the two groups regarding the results of the Roland Morris Disability Questionnaire, Lanss score, and quality of life score (EQ-5D). RESULTS: There was no significant evidence for an overall difference in pain score between the two groups (analysis of variance, F = 3.24, df = 1, P = 0.084), except for the sixth and 12th months, when group B presented a statistically important difference compared with group A (Wilcoxon test). Group B appeared to be more effective, with a statistically significant difference, compared with group A regarding the secondary objectives of the study. CONCLUSIONS: After rigorous and comprehensive assessment by an independent observer, both Discogel alone and Discogel in combination with pulsed radiofrequency produced tangible improvements in pain, function, quality of life, and consumption of analgesics, which were sustained at 12 months.

The efficacy of pulsed radiofrequency intervention of the lumbar dorsal root ganglion in patients with chronic lumbar radicular pain.

INTRODUCTION: In recent years, pulsed radiofrequency (PR) has been used as a minimally invasive pain intervention. However, various studies on the efficacy of PR as modalities for the treatment of radicular pain in lumbar disc herniation have had varied results. OBJECTIVE: This study aims to determine the efficacy of PR in reducing radicular pain among lumbar disc herniation patients compared with conservative treatment. METHODS: This study was conducted using the before-andafter quasi experimental design. There were 50 subjects that fulfilled the inclusion and exclusion criteria and they were divided into an intervention group (n=25) and control group (n=25). The intervention group was given once PR in the dorsal root ganglion. All subjects were assessed for Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) before treatment, at 1- , 2- and 4-week after treatment. RESULTS: At1-, 2- and 4-week, the VAS reduction in the intervention group was statistically significant compared to the control group. Four weeks after the intervention, the VAS score decreased in the intervention group (mean VAS -78.5, SD 16.8) more significantly compared to the control group (p<0.001). The ODI score decreased in the intervention group (mean ODI -61.8, SD 20.1) more significantly than in the control group (p<0.001). CONCLUSION: Finding showed that at1- , 2- and 4-weekPR was more efficacious in reducing radicular pain among lumbar disc herniation patients compared to the conservative therapy.

Effectiveness of Combination of Ultrasonography-Guided Pulsed Radiofrequency Neuromodulation With Steroid at the Suprascapular Nerve in Chronic Shoulder Pain.

BACKGROUND: Suprascapular nerve (SSN) block is a useful tool for pain control of different chronic shoulder pain syndromes. If the short-term effect of nerve block using local anesthetics is not sufficient, pulsed radiofrequency (PRF) neuromodulation of the SSN may provide long-term pain relief. AIM OF INVESTIGATION: The aim of this study was to determine the effectiveness of ultrasonography-guided PRF of the SSN for management of chronic shoulder pain. SUBJECTS AND METHOD: Thirty patients with chronic shoulder pain underwent diagnostic ultrasonography-guided SSN block. After confirmation of positive results (>50% pain relief) via diagnostic testing, PRF of the SSN was performed in 27 patients, followed by application of dexamethasone; however, 2 patients had negative results with diagnostic block and 1 patient dropped out after positive results with diagnostic block. Pain was recorded using the VAS, and active range of motion of the affected shoulder was measured by goniometry (flexion, extension, adduction, abduction, external rotation, internal rotation). Assessments were done on day 0 and after 4, 8, 12, and 24 weeks. STATISTICAL TEST: One-way analysis of variance testing. RESULTS: The VAS score decreased significantly (P < 0.05) immediately after injection, and pain reduction was sustained for up to 24 weeks. Active range of motion in all directions also increased significantly (P < 0.5) after the procedure. CONCLUSION: PRF of the SSN under ultrasonography guidance is a safe and effective treatment modality for management of chronic shoulder pain. The effect of a combination of PRF and a short-acting corticosteroid lasts up to 24 weeks, thereby assisting patients in undergoing relatively painless physiotherapy.

The Outcome of Pulsed Radiofrequency Treatment According to Electodiagnosis in Patients with Intractable Lumbosacral Radicular Pain.

BACKGROUND: Radicular pain is related to lesions that either directly compromise the dorsal root ganglion (DRG) or indirectly compromise the spinal nerve and its roots by causing ischemia or inflammation of the axons. OBJECTIVE: Our study aimed to assess the outcomes of pulsed readiofrequency treatment (PRF) according to electrodiagnosis results in patients with chronic intractable lumbosacral radicular pain. METHODS: A total of 82 failed back surgery syndrome (FBSS) patients were included in this study. All of them underwent electromyography/nerve conduction studies before pulsed radiofrequency (PRF) treatment at the DRG, and they were classified according to the electrodiagnostic results as: group 1, no definite finding (normal); group 2, radiculopathy; and group 3, neuropathy. Pain intensity was assessed according to a numeric rating scale score and the Oswestry Disability Index (ODI) before treatment and at one, three, six, and 12 months after treatment, and successful treatment was defined as a pain score reduction of ≥50% at 12 months, as compared with the pretreatment score. RESULTS: Pretreatment electrodiagnosis identified 28 patients with no definite findings, 31 patients with radiculopathy, and 23 patients with neuropathy. The patients with neuropathy had less pain relief after treatment than those with no definite findings and those with radiculopathy. The prevalence of pain reduction of at least 50% was lower in the neuropathy group than in the other groups. There was no statistically significant difference in ODI between group. CONCLUSION: Outcomes after PRF at the DRG did not show strong differences according to electrodiagnostic findings in FBSS patients with chronic intractable lumbosacral radicular pain.

Microneedle fractional radiofrequency treatment of facial photoageing as assessed in a split-face model.

BACKGROUND: A new therapeutic device passes radiofrequency energy through microneedles to targeted tissue. Three-dimensional photography may be useful for evaluating the clinical efficacy of microneedle fractional radiofrequency (MFR) used on the appearance of rhytids and to improve facial laxity. AIM: To evaluate the efficacy and safety of MFR in the treatment of facial photoageing. METHODS: In total, participants with facial photoageing were enrolled in the study. All volunteers were randomized to receive split-face treatments with MFR 2 months apart. The participants self-evaluated at baseline, Days 1-7, and Months 1 and 3 after the final treatment. Objective evaluation was provided by a three-dimensional in vivo imaging system. In addition, skin melanin index, erythema index, immediate reactions, healing times and other adverse effects were evaluated. RESULTS: Compared with the untreated side, the treated side of most participants improved, based on clinical assessments at the 1- and 3-month follow-up visits after treatment. Both objective and participative assessments were satisfactory. The participants demonstrated a decrease of roughness parameter (Sa) value at each follow-up visit. Compared with pretreatment value, Sa decreased significantly at Months 1 and 3 on the treated side (P < 0.05). Minimal and reversible adverse effects and rapid healing were recorded. CONCLUSIONS: MFR appears to be an excellent treatment for photodamaged facial skin in Chinese patients.

Efficacy and Safety of Computed Tomography-Guided Pulsed Radiofrequency Modulation of Thoracic Dorsal Root Ganglion on Herpes Zoster Neuralgia.

OBJECTIVE: Pulsed radiofrequency (PRF) can relieve postherpetic neuralgia (PHN) caused by herpes zoster (HZ) infection. Nevertheless, its curative effect can vary and may be related to the duration of treatment period. The following study investigates the efficacy and safety of CT-guided PRF modulation on HZ neuralgia over different periods and different time points. MATERIALS AND METHODS: A total of 150 patients with HZ/PHN were enrolled at the Pain Department, Shengjing Hospital of China Medical University between January 2013 and December 2016. According to the course of disease, the patients were randomly divided into group A, which included patients with acute stage (n = 50; course <1 m); group B, which included patients with subacute stage (n = 50; 1 m 3 m). The PRF therapy was performed in all patients by targeting thoracic dorsal root ganglion (DRG). The visual analogue scale (VAS), SF-36, total effective rate of treatment, and dosage of antiepileptic analgesic drugs were observed at different time points, before and after the surgery. RESULTS: Compared to preoperative time, decreased VAS, improved SF-36, and the decreased dosage of antiepileptic analgesic drugs were observed at all time points, and in all groups after surgery (p < 0.05). In group A, pain relief lasted longer, and it further decreased over time. In addition, significantly lower VAS, higher SF-36, and lower dosage of antiepileptic analgesic drugs were found in group A compared to group B, and in group B compared to group C (all p < 0.05). Furthermore, the total effective rates in groups A, B, and C were 88, 72, and 52%, respectively. CONCLUSIONS: CT-guided PRF targeting thoracic DRG for modulation of HZ neuralgia in different periods is safe and effective. It is recommended to perform early intervention therapy at the acute phase of HZ.

A Randomized Controlled Trial to Evaluate the Effect of Pulsed Radiofrequency as a Treatment for Anterior Cutaneous Nerve Entrapment Syndrome in Comparison to Anterior Neurectomy.

BACKGROUND: Chronic abdominal pain can be due to entrapped intercostal nerves (anterior cutaneous nerve entrapment syndrome [ACNES]). If abdominal wall infiltration using an anesthetic agent is unsuccessful, a neurectomy may be considered. Pulsed radiofrequency (PRF) applies an electric field around the tip of the cannula near the affected nerve to induce pain relief. Only limited retrospective evidence suggests that PRF is effective in ACNES. METHODS: A multicenter, randomized, nonblinded, controlled proof-of-concept trial was performed in 66 patients. All patients were scheduled for a neurectomy procedure. Thirty-three patients were randomized to first receive a 6-minute cycle of PRF treatment, while the other 33 were allocated to an immediate neurectomy procedure. Pain was recorded using a numeric rating scale (NRS, 0 [no pain] to 10 [worst pain possible]). Successful treatment was defined as >50% pain reduction. Patients in the PRF group were allowed to cross over to a neurectomy after 8 weeks. RESULTS: The neurectomy group showed greater pain reduction at 8-week follow-up (mean change from baseline -2.8 (95% confidence interval [CI] -3.9 to -1.7) vs. -1.5 (95% CI -2.3 to -0.6); P = 0.045) than the PRF group. Treatment success was reached in 12 of 32 (38%, 95% CI 23 to 55) of the PRF group and 17 of 28 (61%, 95% CI 42 to 72) of the neurectomy group (P = 0.073). Thirteen patients were withdrawn from their scheduled surgery. Adverse events were comparable between treatments. CONCLUSIONS: PRF appears to be an effective and minimally invasive treatment option and may therefore be considered in patients who failed conservative treatment options before proceeding to a neurectomy procedure. Anterior neurectomy may possibly lead to a greater pain relief compared with PRF in patients with ACNES, but potential complications associated with surgery should be discussed.

Comparison of the analgesic effects of pulse radiofrequency and cryoablation in rabbits with mental nerve neuropathic pain.

PURPOSE: After mental nerve injury, several sensory disorders may occur. The alterations in sensation may differ from mild paresthesia to complete anesthesia, or neuropathic pain. Neuropathic pain is a difficult clinical condition to manage. The aim of this study was to compare the analgesic effects of pulsed radiofrequency (PRF) and cryoablation in an experimental mental nerve neuropathic pain model in rabbits. MATERIALS AND METHODS: Fifteen rabbits were divided into three groups. One-third to one-half of the mental nerve was ligated with 4-0 silk sutures. In Group 1, a nonconducting PRF electrode was placed on the mental nerve for 6 min, whereas the mental nerve was exposed to PRF in Group 2. In Group 3, the cryoablation was processed. The responses to thermal and mechanical stimuli were measured at the 1st, 2nd, 3rd, and 4th weeks. RESULTS: There were no statistically significant differences among the groups for thermal withdrawal latency to heat stimulation in any weeks (P > 0.05). However, a significant difference was found between the groups (P < 0.05) in the 3rd and 4th weeks for mechanical withdrawal latency values. CONCLUSIONS: Both PRF and cryoablation therapies are successful in the treatment of experimentally induced mental nerve neuropathic pain in rabbits.