Comparison between bipolar pulsed radiofrequency and monopolar pulsed radiofrequency in chronic lumbosacral radicular pain: A randomized controlled trial

Algofunctional outcome after intra-articular bipolar pulsed radiofrequency ablation for pain in osteoarthritis of the knee: A retrospective study

There is a paucity of research and evidence, regarding the effectiveness of applying bipolar pulsed radiofrequency (bPRF) in osteoarthritis of the knee. This study aimed to search for the impact of intra-articular bPRF (IA-bPRF) on pain, functionality, and quality of life in individuals with advanced knee osteoarthritis. A total of 35 patients experiencing knee pain were included in the study. IA-bPRF was applied at 42 °C temperature, 45 V, with a pulse-width of 20 ms and a frequency of 2 Hz for 3 cycles of 120 seconds. Pain severity was evaluated using the numeric rating scale. Assessment tools included Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Lequesne Algofunctional Index for knee. All measurements were made before the intervention, as well as 2 weeks and 6 months after application of IA-bPRF. Significant improvement was observed in numeric rating scale scores for walking pain from 8.57 ± 0.17 to 4.11 ± 0.35, total WOMAC scores decreased from 75.5 ± 2.71 to 36.7 ± 3.6 and Lequesne Algofunctional Index for knee scores decreased from 18.6 ± 0.70 to 10.4 ± 0.93 by the end of the sixth month (P < .01). WOMAC subgroups for pain, stiffness and functionality, were also significantly lower at the 2nd week and 6th month compared to pre-intervention scores (P < .01). No serious adverse events related to the procedure occurred. IA-bPRF use seems to be safe and effective in relieving pain among individuals with advanced knee osteoarthritis. As a result, with further research, we expect that IA-bPRF may be considered for inclusion in upcoming guidelines for the treatment of chronic pain related to osteoarthritis of the knee.

Novel Ultrasound-Guided Cervical Sympathetic Chain Pulsed Radiofrequency for Subacute Herpes Zoster Neuralgia

Objective

To evaluate the efficacy and safety of the novel ultrasound-guided cervical sympathetic chain pulsed radiofrequency (PRF) for subacute herpes zoster neuralgia.

Materials and Methods

Sixty patients with subacute herpes zoster neuralgia (one month until the third month after the rash onset) on the maxillofacial, head, and neck regions were enrolled in our study. Patients were randomized into two groups: sham-operated (sham) group (n = 30) and radiofrequency (RF) group (n = 30). In the RF group, the affected side cervical sympathetic chain was treated with bipolar high voltage long-duration PRF. In the sham group, the RF cannula was placed at the same position as in the RF group, but without RF energy application. The visual analog scale (VAS), Pittsburgh Sleep Quality Index (PSQI), 36-item Short Form Health Survey (SF-36), analgesic drug usage, incidence of postherpetic neuralgia, and adverse effects were recorded in both groups.

Results

In both groups, compared with preoperative, VAS and PSQI scores decreased, while SF-36 scores improved after the treatment (p < 0.05). The VAS and PSQI scores were significantly lower, whereas the SF-36 scores were significantly higher in the RF group than in the sham group at 1, 30, 90, and 180 days after the treatment (all p < 0.05), and the amount of analgesic drugs consumption was also lower in the RF group than in the sham group (p < 0.05). The incidence of postherpetic neuralgia was lower in the RF group than in the sham group (p < 0.05). No noticeable complications and side effects were observed in either group.

Conclusion

The novel ultrasound-guided cervical sympathetic chain pulsed radiofrequency could effectively relieved subacute herpes zoster neuralgia (one month until the third month after the rash onset) on the maxillofacial, head, and neck regions, and reduced the incidence of postherpetic neuralgia.

Transforaminal Steroid Injection After Dorsal Root Ganglion Pulsed Radiofrequency (DRG-PRF): Impact on Pain Intensity and Disability

INTRODUCTION

Dorsal root ganglion pulsed radiofrequency (DRG-PRF) is frequently used for the treatment of chronic lumbar radicular pain with good outcomes in terms of pain management. Transforaminal epidural steroid injection (TFESI) is often administered immediately after DRG-PRF to increase the anti-inflammatory effects, but support for the synergic mechanism is lacking in the literature. The aim of this study was to investigate the potential role of TFESI immediately after DRG-PRF and its possible role on pain intensity and patient disability.

METHODS

A database of patients who underwent DRG-PRF with or without TFESI immediately after DRG-PRF was retrospectively analysed; propensity score matching was applied to the analysis to reduce possible bias. Pain intensity (numerical rating scale [NRS]) and Oswestry disability index (ODI) were recorded pre-operatively and at the 1- and 3-month follow-up in the two groups of patients.

RESULTS

A total of 252 patients were included in this retrospective analysis, 126 patients in the DRG-PRF + TFESI group and 126 patients in the DRG-PRF group after propensity score matching. Both groups displayed a significant reduction in pain intensity (NRS score reduction; p < 0.0001) and improvement in the ODI (p < 0.0001) from baseline at the 3-month follow-up. Interestingly, the use of TFESI after DRG-PRF was not associated with any clinical benefit as no difference in NRS and ODI was found between the two groups at the 1- and 3-month follow-ups.

CONCLUSIONS

Our study revealed a significant pain reduction and disability improvement after DRG-PRF in patients with lumbar radicular pain. Interestingly, no positive role of TFESI immediately after DRG-PRF was observed. These findings suggest that DRG-PRF provides substantial pain relief, and no added benefit is obtained with subsequent steroid injection. Future prospective studies with expanded follow-up periods are needed to confirm these findings.

The treatment of persistent spinal pain syndrome with epidural pulsed radiofrequency: improvement of the technique

Background

In Persistent Spinal Pain Syndrome (PSPS), Pulsed Radiofrequency (PRF) is a used procedure. The results of PRF in PSPS performed with an electrode placed through the sacral hiatus were reported to be successful on pain in only 32% of patients. We have tried to improve the results by applying a new system to PRF.

Methods

Ten patients were treated with PRF application through a steerable epidural catheter with a reference electrode outside the foramen. This method was named "Optimization Current Flow" (OCF). The duty cycle of PRF was 2 × 10 msec and total exposure time was 150 s. Follow up was planned for 1, 3, and 6 months. The NRS score was considered to be the primary outcome.

Results

In the first 10 patients treatment was successful (69% of the patients) at 6 months follow-up.

Conclusion

This new modality of PRF in patients with PSPS seems to be superior to procedures done with a needle. Further prospective double-blind randomized long-term studies with a significant number of patients are required to validate this technique as there is a need to improve PRF results in PSPS.

Dorsal root ganglion pulsed radiofrequency using bipolar technology in patients with lumbosacral radicular pain duration ≥ 2 years

BACKGROUND

Transforaminal epidural steroid injection (TFESI) or dorsal root ganglion pulsed radiofrequency (PRF) are alternative treatments for lumbosacral radicular pain (LSRP). This study aimed to investigate the clinical efficacy of TFESI combined with dorsal root ganglion PRF using bipolar technology to treat LSRP in patients with pain duration ≥ 2 years.

METHODS

This prospective single-armed cohort study included 20 patients with LSRP duration ≥ 2 years, who underwent treatment of TFESI combined with bipolar PRF. The primary outcomes included numerical rating scale (NRS) and successful treatment rate (pain relief ≥50%). The secondary outcomes included Oswestry Disability Index (ODI), patient satisfaction using the modified MacNab criteria, severe complications, hospital stay and total costs. The final follow-up was 6 months postoperatively.

RESULTS

The successful treatment rate and average pain relief at 6 months postoperatively were 80% and 73.0% ± 17.5%, respectively. The successful treatment rates in patients with and without prior intervention history at 6 months postoperatively were 77.8% and 81.8%, respectively. The mean NRS score significantly decreased from 6.5 ± 0.8 to 1.1 ± 0.7 at 2 weeks postoperatively, to 1.3 ± 0.7 at 3 months postoperatively, and to 1.7 ± 1.0 at 6 months postoperatively (all P < 0.001), while the mean ODI score significantly decreased from 43.5 ± 2.5 to 22.5 ± 4.3 at 2 weeks postoperatively, to 20.0 ± 3.5 at 3 months postoperatively, and to 19.5 ± 3.6 at 6 months postoperatively (all P < 0.001). The excellent and good patient satisfaction at 6 months postoperatively was 85%. No severe complications were observed in this cohort. The average hospital stay and total costs were 3.0 ± 0.5 days and 3.36 ± 0.77 thousand dollars, respectively.

CONCLUSION

The treatment of TFESI combined with PRF using bipolar technology might be an alternative option to treat chronic LSRP in patients with pain duration ≥ 2 years after a failure of conservative treatments, with a favorable 6-month efficacy and inexpensive total costs. However, long-term outcomes and superiority of bipolar procedure over monopolar procedure in patients with longer pain duration should be further investigated in future studies.

Comparison between ultrasound-guided monopolar and bipolar pulsed radiofrequency treatment for refractory chronic cervical radicular pain: A randomized trial

BACKGROUND

Many patients complain of chronic cervical radicular pain, and pulsed radiofrequency (PRF) is known to have a positive effect for alleviating neuropathic pain.

OBJECTIVES

In the present study, we used ultrasound (US) guidance and compared the effects of monopolar PRF with those of bipolar PRF in patients with chronic cervical radicular pain refractory to repeated transforaminal epidural steroid injections.

METHODS

Sixty-six patients with chronic cervical radicular pain were included in this study. Patients were randomly assigned to one of the two groups: monopolar or bipolar PRF group (n= 33 per group). Pain intensity was evaluated using a numeric rating scale (NRS) at pretreatment, and at 1 and 3 months after the treatment. Target stimulation site was the extraforaminal nerve root.

RESULTS

Compared to the pretreatment NRS scores, patients in both groups showed a significant decrease in NRS scores at 1 and 3 months after the treatment. Reductions in the NRS scores over time were significantly larger in the bipolar PRF group. Three months after the treatment, 18 patients (54.5%) in the monopolar PRF group and 27 (81.8%) in the bipolar PRF group reported successful pain relief (pain relief of ⩾50%).

CONCLUSIONS

US-guided PRF can be an effective interventional technique for the management of chronic refractory cervical radiculopathy. Moreover, bipolar PRF has better treatment outcome than monopolar PRF.

Sacroiliac Joint Diagnostic Block and Radiofrequency Ablation Techniques

Radiofrequency ablation (RFA) is a potential treatment for those with sacroiliac joint (SIJ) pain. There is no consensus on the optimal procedural techniques for SIJ diagnostic blocks, or RFA. This article describes different techniques for SIJ diagnostic blocks and RFA, including the relevant innervation that underlies these techniques. SIJ RFA techniques differ in important ways, including lesioning techniques, needle placements, and type of RFA cannula used. Clinicians utilize a variety of image guidance modalities for SIJ RFA; fluoroscopic guidance is standard, although endoscopic and ultrasound-guided techniques are described. Additional studies are necessary to delineate potential differences between SIJ RFA techniques.

Efficacy and Safety of Pulsed Radiofrequency as a Method of Dorsal Root Ganglia Stimulation in Patients with Neuropathic Pain: A Systematic Review

OBJECTIVE

Pulsed radiofrequency (PRF) is a nonablative pain treatment that uses radiofrequency current in short high-voltage bursts, resulting in interruption of nociceptive afferent pathways. We conducted a systematic review with the aim to create a synthesis of evidence about the efficacy and safety of PRF applied to the dorsal root ganglion (DRG) for the treatment of neuropathic pain.

METHODS

We searched MEDLINE, CINAHL, Embase, and PsycINFO through January 8, 2019, as well as ClinicalTrials.gov and the clinical trial register of the World Health Organization. All study designs were eligible. We assessed risk of bias using the Cochrane tool for randomized controlled trials and the Risk Of Bias In Non-Randomized Studies of Interventions (ROBINS-I). We assessed level of evidence using the Oxford tool and quality of evidence with GRADE.

RESULTS

We included 28 studies with participants suffering from lumbosacral, cervical, or thoracic radicular pain, post-herpetic neuralgia, neuropathicbone pain in cancer patients, or carpal tunnel syndrome. Only five studies were randomized controlled trials (RCTs), while others were of nonrandomized designs, predominantly before and after comparisons. A total of 991 participants were included, with a median number (range) of 31 (1-101) participants. Only 204 participants were included in the RCTs, with a median number (range) of 38 (23-62) participants. The overall quality of evidence was low, as the majority of the included studies were rated as evidence level 4 or 5. The quality of evidence was very low.

CONCLUSIONS

Evidence about the efficacy and safety of PRF of the DRG for the treatment of neuropathic pain is based mainly on results from very small studies with low evidence quality. Current research results about the benefits of PRF of the DRG for the treatment of neuropathic pain should be considered preliminary and confirmed in high-quality RCTs with sufficient numbers of participants.

Invasive Treatments for Low Back Disorders

OBJECTIVE

This abbreviated version of the American College of Occupational and Environmental Medicine's Low Back Disorders guideline reviews the evidence and recommendations developed for invasive treatments used to manage low back disorders.

METHODS

Comprehensive systematic literature reviews were accomplished with article abstraction, critiquing, grading, evidence table compilation, and guideline finalization by a multidisciplinary expert panel and extensive peer-review to develop evidence-based guidance. Consensus recommendations were formulated when evidence was lacking and often relied on analogy to other disorders for which evidence exists. A total of 47 high-quality and 321 moderate-quality trials were identified for invasive management of low back disorders.

RESULTS

Guidance has been developed for the invasive management of acute, subacute, and chronic low back disorders and rehabilitation. This includes 49 specific recommendations.

CONCLUSION

Quality evidence should guide invasive treatment for all phases of managing low back disorders.

A Literature Review of Dorsal Root Entry Zone Complex (DREZC) Lesions: Integration of Translational Data for an Evolution to More Accurate Nomenclature

The purpose of this translational review was to provide evidence to support the natural evolution of the nomenclature of neuromodulatory and neuroablative radiofrequency lesions for pain management from lesions of individualized components of the linear dorsal afferent pathway to “Dorsal Root Entry Zone Complex (DREZC) lesions.” Literature review was performed to collate anatomic and procedural data and correlate these data to clinical outcomes. There is ample evidence that the individual components of the DREZC (the dorsal rami and its branches, the dorsal root ganglia, the dorsal rootlets, and the dorsal root entry zone) vary dramatically between vertebral levels and individual patients. Procedurally, fluoroscopy, the most commonly utilized technology is a 2-dimensional x-ray-based technology without the ability to accurately locate any one component of the DREZC dorsal afferent pathway, which results in clinical inaccuracies when naming each lesion. Despite the inherent anatomic variability and these procedural limitations, the expected poor clinical outcomes that might follow such nomenclature inaccuracies have not been shown to be prominent, likely because these are all lesions of the same anatomically linear sensory pathway, the DREZC, whereby a lesion in any one part of the pathway would be expected to interrupt sensory transmission of pain to all subsequent more proximal segments. Given that the common clinically available tools (fluoroscopy) are inaccurate to localize each component of the DREZC, it would be inappropriate to continue to erroneously refer to these lesions as lesions of individual components, when the more accurate “DREZC lesions” designation can be utilized. Hence, to avoid inaccuracies in nomenclature and until more accurate imaging technology is commonly utilized, the evidence herein supports the proposed change to this more sensitive and inclusive nomenclature, “DREZC lesions.”

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Efficacy and safety of pulsed radiofrequency as a method of dorsal root ganglia stimulation for treatment of non-neuropathic pain: a systematic review

BACKGROUND

We systematically reviewed the evidence on the efficacy and safety of dorsal root ganglion (DRG) targeted pulsed radiofrequency (PRF) versus any comparator for treatment of non-neuropathic pain.

METHODS

We searched MEDLINE, CINAHL, Embase, PsycINFO, clinicaltrials.gov and WHO clinical trial register until January 8, 2019. All study designs were eligible. Two authors independently conducted literature screening. Primary outcomes were pain intensity and serious adverse events (SAEs). Secondary outcomes were any other pain-related outcome and any other safety outcome that was reported. We assessed the risk of bias using the Cochrane tool and Risk of Bias In Non-randomized Studies of Interventions (ROBINS-I). We conducted narrative evidence synthesis and assessed the conclusiveness of included studies regarding efficacy and safety.

RESULTS

We included 17 studies with 599 participants, which analyzed various pain syndromes. Two studies were randomized controlled trials; both included participants with low back pain (LBP). Non-randomized studies included patients with the following indications: LBP, postsurgical pain, pain associated with herpes zoster, cervicogenic headache, complex regional pain syndrome type 1, intractable vertebral metastatic pain, chronic scrotal and inguinal pain, occipital radiating pain in rheumatoid arthritis and chronic migraine. In these studies, the PRF was usually initiated after other treatments have failed. Eleven studies had positive conclusive statements (11/17) about efficacy; the remaining had positive inconclusive statements. Only three studies provided conclusiveness of evidence statements regarding safety - two indicated that the evidence was positive conclusive, and one positive inconclusive. The risk of bias was predominantly unclear in randomized and serious in non-randomized studies.

CONCLUSION

Poor quality and few participants characterize evidence about benefits and harms of DRG PRF in patients with non-neuropathic pain. Results from available studies should only be considered preliminary. Not all studies have reported data regarding the safety of the intervention, but those that did, indicate that the intervention is relatively safe. As the procedure is non-destructive and early results are promising, further comparative studies about PRF in non-neuropathic pain syndromes would be welcomed.

Pharmacological and non-pharmacological treatments for neuropathic pain: Systematic review and French recommendations

Neuropathic pain remains a significant unmet medical need. Several recommendations have recently been proposed concerning pharmacotherapy, neurostimulation techniques and interventional management, but no comprehensive guideline encompassing all these treatments has yet been issued. We performed a systematic review of pharmacotherapy, neurostimulation, surgery, psychotherapies and other types of therapy for peripheral or central neuropathic pain, based on studies published in peer-reviewed journals before January 2018. The main inclusion criteria were chronic neuropathic pain for at least three months, a randomized controlled methodology, at least three weeks of follow-up, at least 10 patients per group, and a double-blind design for drug therapy. Based on the GRADE system, we provide weak-to-strong recommendations for use and proposal as a first-line treatment for SNRIs (duloxetine and venlafaxine), gabapentin and tricyclic antidepressants and, for topical lidocaine and transcutaneous electrical nerve stimulation specifically for peripheral neuropathic pain; a weak recommendation for use and proposal as a second-line treatment for pregabalin, tramadol, combination therapy (antidepressant combined with gabapentinoids), and for high-concentration capsaicin patches and botulinum toxin A specifically for peripheral neuropathic pain; a weak recommendation for use and proposal as a third-line treatment for high-frequency rTMS of the motor cortex, spinal cord stimulation (failed back surgery syndrome and painful diabetic polyneuropathy) and strong opioids (in the absence of an alternative). Psychotherapy (cognitive behavioral therapy and mindfulness) is recommended as a second-line therapy, as an add-on to other therapies. An algorithm encompassing all the recommended treatments is proposed.

Pulsed Radiofrequency Neuromodulation Contributes to Activation of Platelet-Rich Plasma in In Vitro Conditions

OBJECTIVES

Recent years have brought new developments in interventional chronic pain management, namely regenerative orthopedics utilizing platelet-rich plasma (PRP) as well as further evolution of pulsed radiofrequency neuromodulation (PRF). Both methods have been used separately. Here, we investigated whether PRF may potentiate the activation of platelets in PRP samples when both these techniques are combined together in in vitro conditions.

MATERIALS AND METHODS

Studies were performed on concentrated PRP samples (PRPs) obtained from acid citrate dextrose-treated blood taken from 11 healthy volunteers. PRPs were divided into four groups: 1) nonactivated PRP; 2) thrombin-activated PRP as a positive control for maximal platelets activation; 3) PRF-treated PRP exposed for 20 min to PRF energy generated by neurotherm radio frequency generator at 500 kHz, with a voltage of 40 V and maximal temperature of 42°C; and 4) a combination of groups 2 and 3.

RESULTS

PRF-induced platelet activation measured by platelet factor 4 (PF4) and ATP release from PRPs was significantly higher compared to nonactivated PRPs, and similar to PF4 and ATP release from thrombin-activated PRPs. Thrombin activation did not potentiate PF4 release in PRF samples and even reduced ATP level. Additionally, PRF neither induced any platelet membrane damage measured by lactic dehydrogenase release from PRP nor modified any platelets viability or metabolism measured by MTT.

CONCLUSIONS

We confirmed that PRF may activate PRP without additional platelet activators. So, a combination of both methods PRF and PRP application may provide a more effective opportunity for tissue regeneration in dentistry, surgery, dermatology, or in orthopedics.

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

BACKGROUND AND OBJECTIVE

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.

METHODS

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 1-3 months after treatment. Successful pain relief was defined as a ⩾ 50% reduction in the scores at 3 months after treatment.

RESULTS

The pain scores changed significantly over time (p< 0.001): pretreatment, 4.9 ± 0.9; 1 month, 3.6 ± 1.4; 2 months, 3.8 ± 1.4; and 3 months, 3.9 ± 1.4. At 1, 2, and 3 months 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 3 months after treatment.

CONCLUSIONS

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.

Pulsed radiofrequency in chronic pain

PURPOSE OF REVIEW

The increasing number of publications on pulsed radiofrequency (PRF) treatment of chronic pain reflects the interest for this technique. We summarize the literature for PRF in five indications: radicular pain, trigeminal neuralgia (TN), occipital neuralgia, shoulder and knee pain.

RECENT FINDINGS

The efficacy and safety of PRF adjacent to the dorsal root ganglion was documented on cervical and on lumbar level.PRF has been used for the treatment of TN. The observed duration of effect is shorter than that of conventional radiofrequency, but no neurological complications are reported with PRF.PRF of the nervi occipitales is superior to steroid injections in occipital neuralgia.Several studies showed that PRF of the nervus suprascapularis may relief shoulder pain and can improve mobility of the shoulder joint.For the treatment of knee pain, different nerves have been targeted for PRF treatment.

SUMMARY

PRF treatment has progressively gained a place in the management of chronic pain syndromes. The concept is appealing because long-lasting effects are reported without complications. Future research is needed with high quality randomized controlled trials and identification of the optimal parameters of PRF in clinical practice.

Effect of intradiscal pulsed radiofrequency on refractory chronic discogenic neck pain: A case report

RATIONALE

Despite medication, exercise, and medical intervention, many patients complain of persistent discogenic neck pain. To manage discogenic neck pain, we performed intradiscal pulsed radiofrequency (PRF) stimulation in a patient with chronic discogenic neck pain refractory to oral medication and epidural steroid injection.

PATIENT CONCERNS

A 26-year-old man presented with a numeric rating scale (NRS) score of 7 for chronic neck pain. His pain was worse when the neck was held in one position for a prolonged period. There was no pain in the upper extremities.

DIAGNOSES

Discography was positive at C4-5. Based on the pain characteristics, and the result of discography, we diagnosed him as having discogenic neck pain originating from C4-5.

INTERVENTIONS

Intradiscal PRF on the C4-5 intervertebral disc was performed under C-arm fluoroscopy. The PRF treatment was administered at 2 Hz and a 20-ms pulsed width for 20 minutes at 60 V with the constraint that the electrode tip temperature should not exceed 42°C.

OUTCOMES

At the 2-week, and 1-month follow-up visits, the patient's pain was completely relieved. At 2, and 3 months after intradiscal PRF, the pain was scored as NRS 2. No adverse effects of intradiscal PRF stimulation were observed.

LESSONS

Application of intradiscal PRF appears to be an effective and safe technique for treating chronic discogenic neck pain.

Effect of bipolar pulsed radiofrequency on refractory chronic cervical radicular pain: A report of two cases

RATIONALE

Despite undergoing transforaminal epidural steroid injection (TFESI), many patients complain of persisting cervical radicular pain. For the management of chronic cervical radicular pain, clinicians are widely applying pulsed radiofrequency (PRF) stimulation to dorsal root ganglions (DRGs). To enhance the effect of PRF stimulation, we conducted bipolar PRF stimulation in 2 patients with chronic cervical radicular pain that was refractory to monopolar PRF and repeated TFESIs.

PATIENT CONCERNS

Patients 1 and 2 presented with a numeric rating scale (NRS) score of 7 and 6 for chronic cervical radicular pain, respectively, despite undergoing monopolar PRF and 2 TFESIs.

DIAGNOSES

On cervical magnetic resonance imaging, foraminal stenosis at the right C6-7 and right central to right foraminal disc protrusion on C6-7 were observed in patients 1 and 2, respectively. Two patients showed a positive response on diagnostic right C7 selective nerve root block with 0.5 mL of 1% lidocaine.

INTERVENTIONS

Bipolar PRF stimulation was performed under C-arm fluoroscopy. Two parallel RF cannulas (less than 1 cm apart) were used for DRG stimulation. The PRF treatment was administered at 5 Hz and a 5-ms pulsed width for 360 seconds at 45 V with the constraint that the electrode tip temperature did not exceed 42°C.

OUTCOMES

At the 2-week and 1-month follow-up, after undergoing bipolar PRF, the pain of patient 1 was completely relieved, and at 2, 3, and 6 months, the pain was scored as NRS 2. In patient 2, at the 2-week follow-up after undergoing bipolar PRF, pain severity was reduced from NRS 6 to 2. The effect of bipolar PRF on patient 2 lasted for at least 6 months. No adverse effects were observed in either patient.

LESSONS

Application of bipolar PRF to DRGs seems to be an effective and safe technique for treating refractory chronic cervical radicular pain.