Pulsed Radiofrequency Stimulation Research Articles

Transforaminal pulsed radiofrequency and epidural steroid injection on chronic lumbar radiculopathy: A prospective observational study from a tertiary care hospital in Vietnam.

Lumbosacral radicular syndrome (LRS) is probably the most frequent neuropathic pain syndrome, exaggerating medical and economy burden on developing countries, such as Vietnam. As a result, the urgence to find an approach which is both affordable and effective always puts great demand on medical researchers. Evaluate the effectiveness of transforaminal pulsed radiofrequency (PRF) stimulation on the dorsal root ganglion (DRG) and epidural steroid injection (ESI) in management of chronic lumbosacral radiculopathy. Seventy-six patients with chronic radicular pain were performed transforaminal PRF + ESI by neurosurgeons. Demographic characteristics and surgical outcomes were recorded on admission, pre-procedural and post-procedural for 1-month, 3-month, 6-month and 12-month follow-up. Primary outcome was measured by using Visual Analogue Scale (VAS), Oswestry disability index (ODI) and Straight Leg Raising Test (SLRT). Secondary outcome was subjectively collected based on short assessment of patients' satisfaction (SAPS). Patients who received transforaminal PRF and ESI showed significant improvements on all three evaluation tools (VAS, ODI, SLRT), compared to that before treatment (p<0.001). Pain relief was achievable and long-lasting, which met patients' expectation. No significant complications were observed for 12 months follow-up. Transforaminal PRF combined with ESI in management of lumbosacral radiculopathy should be a good method of choice for its effectiveness and safety in management of pain.

Lumbar Dorsal Root Ganglion Pulsed Radiofrequency for Spinal Stenosis with an Atypical Fluoroscopic Neurogram: A Case Study

Background: We present a case of an atypical fluoroscopic neurogram pattern for complex chronic axial low back pain during a lumbar dorsal root ganglia (DRG) pulsed radiofrequency stimulation. Case Report: A 70 year old female with a history of complex chronic axial low back pain with radicular leg pain. Initially her pain was described as intermittent, burning, and sharp with an intensity of 9/10 on the Numeric Rating Scale (NRS). This pain worsens with ambulation, lumbar extension, turning, weight bearing and spinal loading activities. MRI imaging noted lumbar anterolisthesis, moderate to severe central spinal stenosis, and mild bilateral neural foraminal space narrowing. From these findings, her pain is likely secondary to components of sacroiliac (SI) joint dysfunction, lumbar facetogenic pain, lumbar radiculitis, and spinal stenosis with neurogenic claudication. A multimodal and multidisciplinary rehabilitation approach involving minimally invasive interventional procedures and medication management was implemented with varying pain relief. She responded to L5 transforaminal epidural nerve root injections, SI joint prolotherapy, and sacral lateral branch radiofrequency ablation. She completed bilateral L5 DRG pulsed radiofrequency stimulation, which did not provide radicular pain relief. We performed a unilateral L4 DRG pulsed radiofrequency stimulation, which revealed an atypical L4 fluoroscopic neurogram pattern. At the 3 month follow up she reported the pain severity to have a NRS between 7-8/10. At 4 months, the pain severity was reported to have a NRS between 4-6/10 with subjective improvements with her daily activities. Conclusion: In a normal transforaminal epidural fluoroscopic neurogram, the anteroposterior view should demonstrate contrast spread medially around the pedicle and laterally following the exiting nerve root. In the case of this patient the combined anatomical presentation of anterolisthesis, central spinal canal stenosis, and circumferential disc bulging are all potential reasons for insufficient contrast passage resulting in the atypical neurogram.

Case Report on Thoracic Pulsed Radiofrequency Stimulation at D6-7 Level for Chronic Chest Wall Pain on Left Side

Case Report on Thoracic Pulsed Radiofrequency Stimulation at D6-7 Level for Chronic Chest Wall Pain on Left Side

Ultrasound-guided caudal epidural pulsed radiofrequency for the treatment of failed back surgery syndrome: Results of a prospective clinical study

BackgroundThe first aim of this study was to investigate the analgesic efficacy of US-guided caudal epidural pulsed radiofrequency (PRF) stimulation in patients with failed back surgery syndrome (FBSS); the second was to evaluate the effects on opioid use, disability, quality of life and patient satisfaction. MethodsThirty patients with > 6-month history of chronic leg pain of >4 on a numerical rating scale (NRS) due to FBSS were included. These patients had unsatisfactory responses to conventional treatments and at least two epidural steroid injections. PRF stimulation with ultrasound guidance was administered to the caudal epidural space. NRS was evaluated before treatment, at 2, 4, and 8 weeks after intervention. Short Form-36 (SF-36) for health-related quality of life, Oswestry Disability Index (ODI), changes in opioid use and patient satisfaction were evaluated at baseline and 8 weeks after treatment. ResultsMean NRS scores were significantly lower at weeks 2, 4 and 8 compared to baseline (P ​< ​0.001). There were significant improvements in SF-36 and ODI scores compared with pretreatment (P ​< ​0.05). It was found that 31% and 13% of opioid users, respectively, discontinued and tapered off their opioid medication. 40% of patients were overall satisfied with the treatment. ConclusionIn a cohort of patients with FBSS, caudal epidural PRF stimulation provided pain relief in 36% of treated subjects. Patients also experienced significant improvement in functionality, quality of life and opioid use. This technique can be considered as an alternative before considering neuromodulation, opiate therapy, or reoperation in patients with FBSS.

Effectiveness of pulsed radiofrequency on the medial cervical branches for cervical facet joint pain

BACKGROUNDCervical facet joint pain (CFP) is one of the most common causes of neck pain and headache. Persistent CFP deteriorates the quality of life of patients and reduces their productivity at work.AIMTo investigate the effectiveness of pulsed radiofrequency (PRF) stimulation of cervical medial branches in patients with chronic CFP. METHODSWe retrospectively included 21 consecutive patients (age = 50.9 ± 15.3 years, range 26-79 years; male: female = 8:13; pain duration = 7.7 ± 5.0 mo) with chronic CFP, defined as ≥ 4 on the numeric rating scale (NRS). We performed PRF stimulation on the cervical medial branches. The outcomes of the PRF procedure were evaluated by comparing the NRS scores for CFP before treatment and 1 and 3 mo after treatment. Successful pain relief was defined as a ≥ 50% reduction in the NRS score at 3 mo when compared with the pretreatment NRS score. RESULTSNo patient had immediate or late adverse effects following PRF. The average NRS score for CFP decreased from 5.3 ± 1.1 at pre-treatment to 2.4 ± 0.6 at the 1 mo follow-up, and 3.1 ± 1.1 at the 3 mo follow-up. Compared to the NRS scores before PRF stimulation, those at 1 and 3 mo after PRF stimulation had significantly decreased. Eleven of the 21 patients (52.4%) reported successful pain relief 3 mo after the PRF procedure. PRF stimulation on cervical medial branches may be a useful therapeutic option to control chronic CFP.CONCLUSIONPRF stimulation of the cervical medial branches may be used as an alternative treatment method in patients with CFP. PRF can effectively alleviate CFP, and is safe to perform.

Pulsed radiofrequency treatment of the dorsal root ganglion in patients with chronic neuropathic pain: A narrative review

Background: Chronic neuropathic pain (CNP) is a complex condition that has profound impacts on quality of life. Pulsed radiofrequency (PRF) on the dorsal root ganglia (DRGs) is a novel treatment that has shown clinical efficacy in pain relief, however, its mechanism remains unknown. Objectives: The objective of this review is to synthesize the literature on inflammatory markers and clinical pain outcomes in CNP patients treated with PRF. Study Design: A narrative review was conducted. Setting: Eligibility criteria included human trials on adults diagnosed with CNP. Monopolar and bipolar PRF treatments on the DRG were included. Methods: Four peer reviewed electronic databases (Medline, EMBASE, PubMed, and Cochrane) were systematically searched for studies on PRF on the DRG to treat CNP. The primary outcome measures included pain scores and cerebrospinal fluid samples taken pre- and posttreatment measuring inflammatory markers. Results: Thirty-three articles were identified in the database searches. Titles, abstracts, and full-text articles were evaluated, and eight articles met the inclusion criteria. The study designs included five randomized-controlled trials and three quasi-experimental studies. Patients: There were 311 patients pooled with an age range of 35–76 years. Types of CNP included chronic radicular pain, postmastectomy pain syndrome, chronic lumbosacral pain, and postherpetic neuralgia. Intervention: Treatments in included studies included monopolar and bipolar PRF stimulation ranging from 120 s at 2 Hz to 360 s with 5 Hz pulses. Measurement: The main findings revealed that PRF treatment provided significant pain relief (P < 0.05), with the greatest pain reduction at 3 months. Pro-inflammatory markers were found to decrease, whereas anti-inflammatory markers increased post-PRF intervention. Limitations: There were differing PRF procedure standards, and it is uncertain whether a higher frequency or duration is correlated with better outcomes. Studies had small sample sizes increasing the margin of error. Longer duration randomized-controlled trials are needed to understand the optimal therapeutic duration using PRF.

The efficacy of pulsed radiofrequency stimulation of the glenohumeral joint and suprascapular nerve for chronic shoulder pain and function compared to physiotherapy and exercise program without pain management

Background: Degenerative tendon diseases are primarily treated conservatively in primary health care and the most important treatment modality is physiotherapy-guided therapeutic rehabilitation. Method: In this prospective observational study, we investigated the effect of two different treatment approaches in patients with chronic shoulder pain. Physiotherapy-guided treatment was compared to interventional pain treatment with radiofrequency nerve stimulation (pRF) before exercise therapy. The primary outcomes were active shoulder mobility and shoulder function assessed by SPADI questionnaire at two and 6-month controls. Results: The results of this study show that pRF treatment combined to physiotherapy seem to effect shoulder function more than physiotherapy alone. With regard to patients with chronic pain and decreased shoulder mobility (65%), pRF treatment showed a significant greater effect in relieving pain and increasing functional outcome assessed by SPADI. Also short-term pain and impairment reduction for 8-12 weeks occurred in patients with chronic rotator cuff lesions. A direct comparison between the rehabilitation programs strengthened the assumption that effective pain management could be necessary to obtain optimal effect of physiotherapy and physical training in patients with chronic (&gt; 3 months) shoulder pain. Conclusion: PRF can be performed in an outpatient department and provides the clinician with an alternative or additional approach to oral drug treatment and intra-articular injection. Further, it may prove to be a useful treatment for patients who are unfit or unwilling to consider surgical intervention Level of evidence: IV.

Behavioral Survey of Effects of Pulsed Radiofrequency on Neuropathic and Nociceptive Pain in Rats: Treatment Profile and Device Implantation

Pulsed radiofrequency (PRF) stimulation is widely used for intractable pain; however, there is no consensus on treatment protocols and appropriate types of pain. We compared effectiveness of bipolar and unipolar PRF on neuropathic or inflammatory pains, and of targets at the dorsal root ganglion (DRG) and sciatic nerve (SN). We also examined efficacy of repetitive PRF stimulations. This preclinical study could serve as an extensive survey before human trials. Spare nerve injury (SNI)-induced neuropathic pain and complete Freund's adjuvant (CFA) injection-induced inflammatory pain were used. Behavioral responses were measured using von Frey test, acetone test, and Hargreave's test at preinjury and postinjury time points. In both models, we evaluated results of DRG stimulation with unipolar PRF (45 V) versus bipolar PRF (5V), stimulation at DRG vs. SN, and repetitive stimulations. Both unipolar and bipolar PRFs reduced SNI- or CFA-induced pain for a similar duration. In the SNI model, PRF-DRG had a stronger effect on tactile pain than PRF-SN but lower effect on cold allodynia, whereas in the CFA model PRF-DRG and PRF-SN showed similar effects. Repetitive PRF stimulation, by open technique or implantation method, produced analogous effect by each stimulus, and no evident analgesic tolerance or neurological deficit was shown. PRF temporarily attenuates neuropathic and inflammatory pain. Bipolar PRF generates significant analgesia with a much lower electrical power than unipolar PRF. Meanwhile, the minor variant effects between PRF-DRG and PRF-SN may indicate distinct mechanisms. The sustained-analgesia by repetitive treatments suggests implantation technique could be a promising choice.

The Clinical Application of Pulsed Radiofrequency Induces Inflammatory Pain via MAPKs Activation: A Novel Hint for Pulsed Radiofrequency Treatment.

Pulsed radiofrequency (PRF) works by delivering short bursts of radiofrequency to a target nerve, thereby affecting nerve signal transduction to reduce pain. Although preliminary clinical investigations have shown that PRF treatment can be used safely as an alternative interventional treatment in patients with refractory pain conditions, unexpected damage to a normal nerve/ganglion is still one of the possible complications of using the PRF strategy. Noxious pain may also be triggered if PRF treatment accidentally damages an intact nerve. However, few studies in the literature have described the intracellular modifications that occur in neuronal cells after PRF stimulation. Therefore, in this study, we evaluated the effects of PRF on unimpaired nerve function and investigated the potential mechanisms of PRF-induced pain. Wistar rats were stimulated with 30–60 V of PRF for 6 min, and mechanical allodynia, cold hypersensitivity, cytokine and matrix metalloproteinase (MMP) production, and mitogen-activated protein kinase activity (p38 MAPK, ERK1/2, JNK/SAPK) were analyzed. The results indicated that PRF stimulation induced a significant algesic effect and nociceptive response. In addition, the protein array and Western blotting analyses showed that the clinical application of 60 V of PRF can induce the activation of MAPKs and the production of inflammatory cytokines and MMPs in the lumbar dorsal horn, which is necessary for nerve inflammation, and it can be suppressed by MAPK antagonist treatment. These results indicate that PRF stimulation may induce inflammation of the intact nerve, which in turn causes inflammatory pain. This conclusion can also serve as a reminder for PRF treatment of refractory pain.

Pulsed Radiofrequency of the Trigeminal Ganglion for Treating Postherpetic Neuralgia of the Ophthalmic Branch.

Postherpetic neuralgia (PHN) is a painful, long-lasting condition as a consequence of nerve damage resulting from a herpes zoster infection. Although there are many different treatments available to reduce pain duration and severity, PHN is often refractory to them and no single therapy shows an effective cure for all cases of PHN, especially for those involving the ophthalmic branch of the trigeminal nerve. Pulsed radiofrequency (PRF) is a minimally invasive procedure for pain treatment that has been practiced over the past decade. However, its clinical efficacy and safety for treating PHN involving the ophthalmic branch of the trigeminal nerve have not been evaluated. Objective. This study aimed to evaluate the efficacy and safety of PRF for treating PHN involving the ophthalmic branch of the trigeminal ganglion. Study Design. An observational study. Setting. All patients received PRF of the ophthalmic branch of the trigeminal nerve, pain intensity was assessed by a visual analogue scale (VAS), and complications before and after PRF stimulation were noted. Methods. Thirty-two patients with PHN of the ophthalmic branch were treated by PRF of the ophthalmic branch with controlled temperature at 42°C for 8 min. Pain relief, corneal reflex, sleep quality, and satisfaction were assessed for all patients. Results. Thirty out of 32 patients (93.75%) reported significant pain reduction after PRF treatment. Twenty-eight of them (87.5%) were satisfied with their sleep and obtained a pain score lower than 3 following the procedure. Only two patients had a recurrence of the severe burning pain and returned to the hospital for other medical therapies 2 weeks after the PRF procedure. No patient lost the corneal reflex. Limitations. This study is an observational study and a nonprospective trial with a short-term follow-up period. Conclusion. PRF of the trigeminal ganglion of the ophthalmic branch can significantly reduce pain sensation and improve sleep quality and satisfaction for PHN of the ophthalmic branch.

The synergistic effects of applying pulsed radiofrequency lesioning of the suprascapular nerve plus physical therapy on pain and function in patients with adhesive capsulitis: A protocol of a prospective, randomized, controlled trial.

Background:To our knowledge, there have been no published clinical trials to assess the synergistic effects of applying pulsed radiofrequency (PRF) stimulation of the suprascapular nerve (SSN) plus physical therapy on pain and function in patients with adhesive capsulitis. Therefore, we will conduct this present randomized, double-blind study to evaluate the synergistic effects of applying PRF stimulation of the SSN plus physical therapy on pain and function in patients with adhesive capsulitis.Methods:The study protocol is a randomized, controlled, double-blind design. Recruitment will be started in March 2021 and completed in October 2022. The treating surgeon will assess 90 patients for eligibility. The study protocol was approved through Institutional Review Board in the People's Hospital of Beilun district of Ningbo. Each patient will be randomized into 3 treatment groups, receiving PRF stimulation of the SSN or physical therapy or both of them. After baseline examination, all patients will be given a full explanation of the treatment protocol and will be required to sign a written informed consent for study participation and for publication of the results. All the data collectors, surgeons, statistical analysts, as well as result assessors are not aware of grouping assignment. The outcomes include Constant score, visual analog scale score, range of motion, and strength.Results:This protocol will provide a reliable theoretical basis for the following research.Conclusion:It is assumed that there will be a remarkable difference in postoperative outcomes between the intervention and control groups.Trial registration number:10.17605/OSF.IO/PZ9ES.

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

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. We reviewed articles which investigated the effectiveness of intradiscal PRF for controlling discogenic LBP. 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. 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. 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.

Efficacy of pulsed radiofrequency in controlling pain caused by spinal disorders: a narrative review.

Pulsed radiofrequency (PRF) stimulation has been safely and effectively applied for controlling various types of pain. Here, we aimed to systematically review the literature pertaining to the efficacy of PRF stimulation for managing pain associated with spinal disorders. We conducted a PubMed search for papers published until August 20, 2019, that used PRF to treat pain resulting from spinal disorders. The following inclusion criteria were applied when selecting the articles: (I) patients' pain was caused by spinal disorders; (II) PRF stimulation was applied on the spinal structure; and (III) after PRF stimulation, follow-up evaluation was performed to assess the change in pain intensity. Review articles were excluded. The primary literature search yielded 168 relevant papers. After reading their titles and abstracts and evaluating their eligibility based on the full-text articles, we finally included 59 publications in this review. The therapeutic outcomes reported in the selected studies showed that PRF is an effective treatment for cervical and lumbar radicular pain. Similarly, PRF stimulation seems to be effective for treating cervical joint (cervical facet and atlantoaxial joints) pain and lumbar facet joint pain. PRF stimulation has also resulted in positive outcomes in some studies, in which patients were treated for other disorders, including cervicogenic headache, discogenic neck pain, thoracic facet joint pain, discogenic back pain, and coccydynia. Nevertheless, there is insufficient evidence for the efficacy of PRF stimulation in these disorders. In conclusion, our review provides insights into the degree of evidence available on the effectiveness of PRF stimulation for treating pain associated with each of the spinal disorders reviewed. This information will help clinicians make informed decisions on using PRF stimulation to treat various spinal conditions and manage the associated pain.

Effects of intra-articular pulsed radiofrequency current administration on a rabbit model of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by synovial proliferation and inflammation. Intra-articular corticosteroid injections are commonly used for the treatment of arthritis affecting one or two joints. Although corticosteroid injections are fast-acting, repeated usage can result in severe adverse events. Recently, intra-articular pulsed radiofrequency (PRF) stimulation has been proposed to treat arthritis. The aim of the present study was to compare the effectiveness of intra-articular PRF with corticosteroid injection based on histopathological and motion analysis of an ovalbumin (OVA)-induced RA rabbit model. RA was induced in the right knee joint of 18 rabbits via OVA injection. The rabbits were randomly allocated into a PRF, an intra-articular corticosteroid injection or a sham PRF stimulation group. Movement was assessed in the rabbits before treatment, then at 2, 4 and 8 weeks after treatment using walking distance, fast walking time and mean walking speed. Histopathological evaluation of the distal femur and synovium was conducted 2, 4 and 8 weeks after treatment. Motion analysis demonstrated that changes in all movement variables showed significant group and time interaction as well as group effect among the three groups. The semiquantitative score based on the histopathological findings for the distal femoral condyle decreased 2 and 4 weeks after both the PRF and steroid groups, compared with the sham PRF group. Moreover, in the synovium, the semiquantitative histological score in the PRF and steroid groups tended to be lower compared with the sham PRF group, although this result was not statistically significant. Thus, intra-articular PRF stimulation may delay cartilage destruction and improve functional motion in RA.

Effectiveness of Ultrasound-Guided Pulsed Radiofrequency Treatment in Patients with Refractory Chronic Cervical Radicular Pain

Background: The effect of pulsed radiofrequency (PRF) stimulation for alleviating cervical radicular pain has been demonstrated in several previous studies. Objectives: We aimed to evaluate the effectiveness of PRF with ultrasound (US) guidance in patients with chronic cervical radicular pain that was refractory to repeated transforaminal epidural steroid injections (TFESIs). Study Design: A prospective outcome study. Setting: The outpatient clinic of a single academic medical center. Methods: This study included 49 patients with chronic cervical radicular pain, unresponsive to repeated TFESIs, and who underwent PRF stimulation under US guidance. Using US, a cannula was inserted toward the cervical spinal nerve. The pain intensity was evaluated using the Numeric Rating Scale (NRS-11) for cervical radicular pain at pretreatment and 1, 3, and 6 months posttreatment; and the Neck Disability Index (NDI) was used for evaluating functional disability before treatment and 6 months posttreatment. Successful pain relief was defined as ≥ 50% reduction in the NRS-11 score as compared with the score before treatment. Results: Cervical radicular pain was significantly reduced at 1, 3, and 6 months postPRF (P &lt; 0.001). At 6 months post-PRF, functional disability (NDI score) had significantly reduced, and 63.3% of the patients achieved successful pain relief. Limitations: The small number of included patients and no long-term follow-up. Conclusions: PRF stimulation under the guidance of US is a potentially effective treatment method for managing refractory chronic cervical radicular pain. Key words: Ultrasound, pulsed radiofrequency, cervical radicular pain, chronic pain

Clinical effectiveness of caudal epidural pulsed radiofrequency stimulation in managing refractory chronic leg pain in patients with postlumbar surgery syndrome.

We evaluated the effect of caudal epidural pulsed radiofrequency stimulation in patients with chronic lumbosacral radicular pain due to postlumbar surgery syndrome who were unresponsive to at least two epidural steroid injections through the interlaminar, transforaminal, or caudal route. We recruited 25 patients with chronic persistent radicular pain in one or both legs (⩾ 4 on the Numeric Rating Scale [NRS]) despite spinal surgery. They were unresponsive to at least two epidural steroid injections. We retrospectively conducted this study. Electrode needles were placed into the epidural space (S2-3 intervertebral level) through the sacral hiatus, and pulsed radiofrequency stimulation was administered. The outcomes were evaluated using the NRS scores for radicular pain before treatment and 1-3months after treatment. Successful pain relief was defined as a ⩾ 50% reduction in the scores at 3months after treatment. The pain scores changed significantly over time (p< 0.001): pretreatment, 4.9 ± 0.9; 1month, 3.6 ± 1.4; 2months, 3.8 ± 1.4; and 3months, 3.9 ± 1.4. At 1, 2, and 3months after pulsed radiofrequency (PRF) procedure, the NRS scores were significantly reduced compared with the scores before the treatment. Eight patients (32%) reported successful pain relief at 3months after treatment. Although only 32% of the patients with postlumbar surgery syndrome showed successful pain relief after treatment, the result is encouraging because we recruited only patients unresponsive to repeated epidural steroid injections.

Can Pulsed Radiofrequency of the Occipital Nerves Cause Sedation? A New Perspective of Existing Knowledge.

BackgroundPulsed radiofrequency stimulation (PRF) of the greater and lesser occipital nerves (GON and LON) has neuromodulative and analgesic properties.ObjectivesThe aim of this study was to investigate whether the PRF of the occipital nerves can cause sedation.MethodsThis is an observational case series study in Pain Management Unit of Attikon University Hospital. Patients suffering from primary headaches were scheduled for PRF of occipital nerves following a standardized protocol. The Bispectral Index device was applied and recorded every minute throughout the procedure.Results22 patients were studied. BIS values were lowered in all but three patients during GON stimulation, and in all patients during LON stimulation. Values of decline compared to baseline ranged between 0 - 23 (median 8.5) for GON and 1 - 27 (median 14) for LON, with LON decline being significantly lower.ConclusionsPRF at the occipital nerves led to mild sedation in all patients. Further studies are required to investigate this effect and clarify the exact mode of action of pulsed radiofrequency.

The Effectiveness of Pulsed Radiofrequency on Joint Pain: A Narrative Review.

Pulsed radiofrequency (PRF) stimulation has been safely and effectively applied for controlling various types of pain. We reviewed the literature on the efficacy of PRF for controlling pain in joint disorders. We searched PubMed for papers published prior to September 7, 2019, that used PRF to treat pain due to joint disorders. The key search phrases for identifying potentially relevant articles were (PRF AND joint) OR (PRF AND arthritis) OR (PRF AND arthropathy). The following inclusion criteria were applied for the selection of articles: (1) patients' pain was caused by joint disorders; (2) PRF stimulation was applied to manage joint-origin pain; and (3) after PRF stimulation, follow-up evaluation was performed to assess the reduction in pain intensity. Moreover, joints with more than 3 reported PRF studies were included in our review. The primary literature search yielded 141 relevant papers. After reading their titles and abstracts and assessing their eligibility based on the full-text articles, we finally included 34 publications in this review. Based on the positive therapeutic outcomes of previous studies, PRF stimulation seems to be an effective treatment for cervical and lumbar facet, sacroiliac, knee, and glenohumeral joint pain. PRF appears to be beneficial. For confirmation of the effectiveness of PRF on joint pain, more high-quality studies are needed. Our review provides insights on the degree of evidence according to pain in each joint, which will help clinicians make informed decisions for using PRF stimulation in various joint pain conditions.

Translocation of AMPA Receptors in the Dorsal Horn of the Spinal Cord Corresponding to Long-term Depression Following Pulsed Radiofrequency Stimulation at the Dorsal Root Ganglion.

Pulsed radiofrequency stimulation at the dorsal root ganglion is used for treatment of radicular pain; however, its mechanism for neuropathic pain treatment has not been fully elucidated. Here, we investigated whether pulsed radiofrequency stimulation affects the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, which play a critical role in synaptic plasticity. Neuropathic pain was studied using a radicular neuropathic pain model (43 female Sprague-Dawley rats; 200-250 g). In total, 28 rats were assigned to the following groups for fraction analysis: a control group, a control + pulsed radiofrequency stimulation group, a disc pain group, and a disc pain + pulsed radiofrequency stimulation group. For nonfraction analysis of Glutamate A1 (GluA1) and GluA2 subunits, a total of 15 female Sprague-Dawley rats were assigned to a control group, a disc pain group, and a disc pain + pulsed radiofrequency stimulation group. Pulsed radiofrequency stimulation and subsequent analysis were conducted three days after surgery. AMPA receptor subunits, GluA1 and GluA2, in the radicular neuropathic pain model were upregulated compared with those in the control group three days after surgery. Pulsed radiofrequency stimulation induced the translocation of GluA1 and GluA2 subunits from the synaptosome to cytosol without a change in the total amount of AMPA receptors in the dorsal horn. Our results demonstrated that pulsed radiofrequency stimulation affected the synaptic plasticity corresponding to long-term depression. Thus, we show that long-term depression from pulsed radiofrequency stimulation is associated with analgesic effects in the radicular neuropathic pain model following peripheral inflammation.

CT-Guided Stellate Ganglion Pulsed Radiofrequency Stimulation for Facial and Upper Limb Postherpetic Neuralgia

Objective: Postherpetic neuralgia (PHN) is the most common complication of herpes zoster, manifesting as a persistent, spontaneous, knife-like pain or paroxysmal burning that seriously affects a patient’s quality of life. An effective treatment of PHN is lacking. This retrospective study examined the efficacy and safety of stellate ganglion (SG) pulsed radiofrequency (PRF) on facial and upper limb PHN.Methods: Eighty-four patients with PHN on the face or upper limbs were enrolled for the study. Patients were randomly divided into two surgical groups according to the order of enrollment; one group underwent SG block (SG-B group, n = 42) and the other underwent SG pulsed radiofrequency (SG-P group, n = 42). After surgery, patients were followed at 1 week, 2 weeks, 1 month, 3 months, and 6 months. Observation at each follow-up included basic patient characteristics, visual analog scale (VAS), quality of life (QOL) using Physical Component Summary (PCS), and Mental Component Summary (MCS) to assess, total effective rate, complications and side effects.Results: Compared with preoperative values, VAS decreased in both groups after surgery (P < 0.05). In the SG-B group, VAS increased after 1 month, while in the SG-P group, VAS gradually decreased at later follow-up time points. VAS decreased more significantly in the SG-P group after 1 month (P < 0.05). PCS and MCS increased in both groups after the operation, and the difference was significant compared with preoperative values (P < 0.05). The total effective rates of the SG-B and SG-P groups were 64.3 and 83.3%, respectively. The total effective rate of the SG-P group was higher than that of the SG-B group (P < 0.05). The incidence of complications and side effects in the SG-B group was higher than that in the SG-P group (P < 0.05).Conclusion: SG pulsed radiofrequency treatment of facial and upper limb PHN is safe and effective. It is a treatment method worth promoting.