Percutaneous pulsed radiofrequency in the treatment of cervical and lumbar radicular pain

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.

Does transforaminal epidural steroid injection added to dorsal root ganglion pulsed radiofrequency treatment increase efficacy?

Objectives

This study aimed to compare the treatment outcomes between dorsal root ganglion (DRG) pulsed radiofrequency (PRF) and DRG PRF plus transforaminal epidural steroid injection (TFESI) in patients with chronic lumbosacral radicular pain.

Patients and methods

Eighty-one patients (39 males, 42 females; mean age: 57.5±11.9 years; range 18 to 65 years) who underwent DRG PRF (Group 1) and 59 patients (34 males, 25 females; mean age: 58.7±12.3 years; range 18 to 65 years) who underwent DRG PRF plus TFESI (Group 2) between February 2021 and June 2022 were enrolled in the retrospective study. A Visual Analog Scale (VAS) was used to assess pain severity. Patients in both groups were evaluated before treatment and at four weeks and six months after treatment.

Results

The four-week and six-month VAS scores were significantly lower than the baseline VAS scores in both groups. There was no significant difference between the groups in terms of the VAS scores at baseline, four weeks, and six months. There was no significant difference between the groups in terms of the rate of pain reduction of 50% or more at either measurement point. The presence or absence of a previous lumbar surgery had no effect on achieving a significant decrease in pain.

Conclusion

Although DRG PRF and TFESI are easy to apply together, adding corticosteroids to DRG PRF treatment for patients with chronic radicular pain did not improve long-term outcomes.

Effectiveness of Pulsed Radiofrequency Based on the Minimum Clinically Important Differences in Lumbar Spine-Related Pain in Patients without Recent Lumbar Surgery

BACKGROUND

Pulsed radiofrequency (PRF) has been used for treatment of chronic pain in several body regions, including axial and radicular pain. However, a limited number of reports have specifically demonstrated the effectiveness of PRF for spine-related pain among nonsurgical patients. Therefore, we evaluated the effectiveness of PRF for lumbar spine-associated pain in patients without recent spine surgery, and identified the factors associated with clinically meaningful improvement in pain and quality of life.

METHODS

Records of patients who underwent PRF for lumbar spine-related pain and were followed up over 6 months between 2019 and 2022 were retrospectively reviewed. Data on patient demographics, interventional factors, and patient-reported outcomes, such as the numerical rating scale (NRS) and EuroQol Group 5 Dimension 5-Level Quality of Life (EQ-5D-5 L), were collected. Patients were divided into 2 groups (responsive and nonresponsive) based on the NRS and EQ-5D-5 L scores using the previously reported minimal clinically important difference values of the NRS and EQ-5D-5 L as cutoffs, and baseline parameters were compared to identify contributing factors.

RESULTS

Forty-three patients were included in the final analysis. The NRS and EQ-5D-5 L scores improved significantly at 3 and 6 months after PRF compared to baseline. The groups with NRS and EQ-5D-5 L improvement over the minimal clinically important difference had significantly higher baseline NRS and EQ-5D-5 L scores.

CONCLUSIONS

Our results demonstrated that PRF improved pain and patient-reported outcomes for spine-related pain for at least 6 months in our patient cohort. PRF may be a good option for treating lumbar spine-related issues, even with severe pain and/or dysfunction.

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.

Pulsed Radiofrequency Decreases pERK and Affects Intracellular Ca2+ Influx, Cytosolic ATP Level, and Mitochondrial Membrane Potential in the Sensitized Dorsal Root Ganglion Neuron Induced by N-Methyl D-Aspartate

Background

The molecular mechanism of pulsed radiofrequency (PRF) in chronic pain management is not fully understood. Chronic pain involves the activation of specific N-Methyl D-Aspartate receptors (NMDAR) to induce central sensitization. This study aims to determine the effect of PRF on central sensitization biomarker phosphorylated extracellular signal-regulated kinase (pERK), Ca²⁺ influx, cytosolic ATP level, and mitochondrial membrane potential (Δψm) of the sensitized dorsal root ganglion (DRG) neuron following NMDAR activation.

Methods

This study is a true experimental in-vitro study on a sensitized DRG neuron induced with 80 µM NMDA. There are six treatment groups including control, NMDA 80 µM, Ketamine 100 µM, PRF 2Hz, NMDA 80 µM + PRF 2 Hz, and NMDA 80 µM + PRF 2 Hz + ketamine 100 µM. We use PRF 2 Hz 20 ms for 360 seconds. Statistical analysis was performed using the One-Way ANOVA and the Pearson correlation test with α=5%.

Results

In the sensitized DRG neuron, there is a significant elevation of pERK. There is a strong correlation between Ca²⁺, cytosolic ATP level, and Δψm with pERK intensity (p<0.05). PRF treatment decreases pERK intensity from 108.48 ± 16.95 AU to 38.57 ± 5.20 AU (p<0.05). PRF exposure to sensitized neurons also exhibits a Ca²⁺ influx, but still lower than in the unexposed neuron. PRF exposure in sensitized neurons has a higher cytosolic ATP level (0.0458 ± 0.0010 mM) than in the unexposed sensitized neuron (0.0198 ± 0.0004 mM) (p<0.05). PRF also decreases Δψm in the sensitized neuron from 109.24 ± 6.43 AU to 33.21 ± 1.769 AU (p<0.05).

Conclusion

PRF mechanisms related to DRG neuron sensitization are by decreasing pERK, altering Ca²⁺ influx, increasing cytosolic ATP level, and decreasing Δψm which is associated with neuron sensitization following NMDAR activation.

Safety of Conventional and Pulsed Radiofrequency Lesions of the Dorsal Root Entry Zone Complex (DREZC) for Interventional Pain Management: A Systematic Review

Study Design

Systematic literature review.

Objective

The goal of this systematic review is to assess the clinical safety and potential complications of conventional and pulsed radiofrequency ablations targeting dorsal root entry zone complex (DREZC) components in the treatment of chronic pain.

Background

There is a growing popularity for the use of radiofrequency ablation (RFA) techniques targeting DREZC components by pain management physicians for an increasing variety of indications. To date, we lack a systematic review to describe the safety and the type of complications associated with these procedures.

Methods

This was a systematic literature review. This systematic search was limited to peer-reviewed literature using “radiofrequency ablation” as a search keyword using PubMed’s database for manuscripts published between inception and December 2020. Abstracts that involved the application of radiofrequency currents, of any modality, to DREZC components for the treatment of pain were included for full-text review. Search was limited to original data describing clinical outcomes following RFA performed for pain indications only, involving the DREZC components outlined above, in human subjects, and written in English. The primary outcomes were complications associated with conventional RFA and pulsed radiofrequency ablation (PRF). Complications were categorized as type 1 (persistent neurological deficits or other serious adverse events, defined as any event that resulted in permanent of prolonged injury; type 2 (transient neuritis or neurological deficits, or other non-neurological non-minor adverse event); type 3 (minor adverse events (e.g., headache, soreness, bruising, etc.).

Results

Of the 62 selected manuscripts totaling 3157 patients, there were zero serious adverse events or persistent neurological deficits reported. A total of 36 (1.14%) transient neurological deficits, cases of transient neuritis, or non-minor adverse events like uncomplicated pneumothorax were reported. A total of 113 (3.58%) minor adverse events were reported (bruising, transient site soreness, headache).

Conclusions

This systematic review indicates that the use of RFA lesion of the DREZC for interventional pain management is very safe. There were no serious adverse effects with a sizable sample of randomized controlled trial (RCT), prospective observational, and retrospective 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.

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.

Long-term Inhibition of Soleus H-reflex with Epidural Adhesiolysis and Pulsed Radiofrequency in Lumbosacral Neuropathic Pain

INTRODUCTION

Scientific data about neurophysiological changes subsequent to pulsed radiofrequency (PRF) are still lacking. The goal of this study was to evaluate sural nerve conduction and Hoffmann reflex (H-reflex) in soleus muscle following adhesiolysis and PRF in patients with unilateral chronic lumbosacral L5-S1 neuropathic radiating pain.

METHODS

Seventeen patients received two cycles of 240 seconds high-voltage PRF and epidural adhesiolysis. Sural nerve action potential (SNAP) and the ratio of maximum H-reflex to maximum M response (H/M ratio) as well as pain scores were collected in both lower limbs before, immediately following, and 1 month after the treatment.

RESULTS

At follow-up, a significant reduction in numeric rating scale (NRS) and Douleur Neuropathique 4 Questions (DN4) scores was observed in 53% of patients reporting pain improvement of ≥ 30% over baseline. The H/M ratio was decreased in the affected limb following PRF (P = 0.01) and 1 month after the treatment (P = 0.04). A direct correlation was observed between H/M ratio variation and NRS score at follow-up in the treated limb (P = 0.04). No significant difference in sural nerve latency, amplitude, and velocity was detected between affected and normal side after treatment and at follow-up.

CONCLUSIONS

Epidural adhesiolysis and PRF of the dorsal root ganglion seem to significantly affect spinal reflexes in patients with lumbosacral neuropathic radiating pain.

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.

Transforaminal Epidural Injection of Local Anesthetic and Dorsal Root Ganglion Pulsed Radiofrequency Treatment in Lumbar Radicular Pain: A Randomized, Triple-Blind, Active-Control Trial

BACKGROUND

Lumbar radicular pain (LRP) results from inflammation and irritation of lumbar spinal nerves and the dorsal root ganglion (DRG).

METHODS

Our study is a prospective, triple-blind, randomized, activecontrol trial (CTRI/2016/02/006666) comparing transforaminal epidural local anesthetic (LA) injection and pulsed radiofrequency treatment of DRG in patients with chronic LRP. Patients with LRP after failed conservative management for >3 months received selective diagnostic nerve root block with 1 mL 2% lidocaine. Fifty patients showing positive responses were divided into groups of 25 each. The LA group received transforaminal epidural injection of 1 mL 0.5% bupivacaine. The lumbar pulsed radiofrequency (LPRF) group received transforaminal epidural injection of 1 mL 0.5% bupivacaine with 3 cycles of pulsed radiofrequency of the DRG for 180 seconds RESULTS: Both groups were compared by observing pain intensity on a 0- to 100-point VAS and improvement in functional status by the Oswestry Disability Index (ODI version 2.0) at 2 weeks and 1, 2, 3, and 6 months. All baseline variables were comparable between the 2 groups. Statistically significant reduction in both outcomes was seen in the LPRF group compared to the LA group from 2 weeks to 6 months. One hundred percent of patients in the LPRF group had a ≥20- point decrease in VAS and significant percentage reduction in ODI at all time intervals up to 6 months, whereas it was seen in 80% and 28% of patients in the LA group at 3 and 6 months, respectively. No complications were seen in any patients CONCLUSION: Pulsed radiofrequency of the DRG applied for longer duration results in long-term pain relief and improvement in the functional quality of life in patients with chronic LRP.

The effect of needle tip position on the analgesic efficacy of pulsed radiofrequency treatment in patients with chronic lumbar radicular pain: a retrospective observational study

Background

Pulsed radiofrequency (PRF) is a treatment modality that alleviates radicular pain by intermittently applying high-frequency currents adjacent to the dorsal root ganglion. There has been no comparative study on analgesic effect according to the position of the needle tip in PRF treatment. The objective of this study is to evaluate the clinical outcomes of PRF according to the needle tip position.

Methods

Patients were classified into 2 groups (group IP [group inside of pedicle] and group OP [group outside of pedicle]) based on needle tip position in the anteroposterior view of fluoroscopy. In the anteroposterior view, the needle tip was advanced medially further than the lateral aspect of the corresponding pedicle in group IP; however, in group OP, the needle tip was not advanced. The treatment outcomes and pain scores were evaluated at 4, 8, and 12 weeks after applying PRF.

Results

At 4, 8, and 12 weeks, there were no significant differences between the successful response rate and numerical rating scale score ratio.

Conclusions

The analgesic efficacy of PRF treatment did not differ with the needle tip position.

Dorsal root ganglion pulsed radiofrequency treatment for chronic cervical radicular pain: a retrospective review of outcomes in fifty-nine cases

Pulsed radiofrequency treatment adjacent to the cervical dorsal root ganglion is used to treat persistent cervical radicular pain that has not responded to conservative therapies. This technique has gained popularity in years for both cervical and lumbosacral radicular pain. The evidence to support its use is still evolving.

METHODS

We performed a retrospective review of outcomes in 59 patients who underwent this therapy over a 3-year period in our institution. We evaluated a reduction in pain, duration of pain relief, reduction in use of analgesics and progression to surgery.

RESULTS

Our results demonstrated 49 patients experienced some relief. Forty patients of the 59 experienced an improvement in pain of 50% or more. The mean duration of relief in this group was 37 weeks. Seven patients experienced complete resolution of their pain. In this group, the mean duration of relief was 39 weeks. Regarding the 53 patients who were taking medication for pain prior to the procedure, 37 patients reduced or discontinued their usage after the procedure.

CONCLUSION

Despite the limitations of a retrospective study, we feel our study adds to the growing evidence base that pulsed radiofrequency treatment adjacent to the cervical dorsal root ganglion has a role in the treatment of chronic cervical radicular pain.

Transforaminal epidural steroid injection combined with pulsed radio frequency on spinal nerve root for the treatment of lumbar disc herniation

Background

Lumbar disc herniation (LDH) is a common disease in clinical practice. The symptoms recur and are aggravated by time; severe pain and long-term movement disorder cause physiological and psychological problems that affect the quality of life of patients. Therefore, relieving the pain symptoms and promoting functional recovery are the primary goals that have gained increased attention.

Objective

To assess the efficacy of CT-guided transforaminal epidural steroid injection (TFESI) combined with pulsed radio frequency (PRF) on spinal nerve root for the treatment of LDH.

Study design

Retrospective comparative study.

Setting

Shengjing Hospital of China Medical University.

Methods

A total of 135 patients with LDH were selected from the Department of Pain Management in the Shengjing Hospital of China Medical University between January 2014 and December 2016. All patients were divided into three groups according to the order of entry (n=45): TFESI (group A); PRF on spinal nerve root (group B); and TFESI combined with PRF on spinal nerve root (group C). The visual analog scale (VAS), Oswestry disability index (ODI), and global perceived effect (GPE) before treatment and at different time points after treatment were observed, and patients' satisfaction was assessed.

Results

At every point of observation, the VAS and ODI decreased significantly as compared to that before treatment in all groups (P<0.05). The VAS and ODI in group A at 3 and 6 months after treatment were significantly higher than that in the other two groups (P<0.05). At day 1, day 14, and 1 month after treatment, the VAS and ODI in group C were significantly lower than that in group B (P<0.05). The GPE in group C was high in the early days, while that at day 14 and 1 month after treatment was significantly higher than that in the other two groups (P<0.05); no significant difference was observed in GPE at 3 and 6 months after treatment between groups B and C (P>0.05).

Conclusion

TFESI combined with PRF for the treatment of LDH could effectively and rapidly relieve lumbago and radicular pain and achieve long-term remission. Although the method is widely applicable, the precise selection of patients is imperative.

Effectiveness of pulsed radiofrequency treatment on cervical radicular pain: A meta-analysis

BACKGROUND

Cervical radicular pain is a challenging medical problem in terms of therapeutic management. Recently, pulsed radiofrequency (PRF) stimulation on the dorsal root ganglion (DRG) has been used to control several types of chronic pain. However, its effect on cervical radicular pain is still not well studied. To conduct a meta-analysis of available clinical studies on PRF treatment in patients with cervical radicular pain induced by cervical spine disease that was not responsive to other conservative treatments.

METHODS

A comprehensive database search was conducted on PubMed, Embase, Cochrane Library, and SCOPUS. We included studies published up to August 31, 2017, that fulfilled our inclusion and exclusion criteria. The pain degrees measured using visual analog scale (VAS) at pretreatment and after PRF on the DRG were collected for the meta-analysis. The Cochrane Collaboration's Handbook and Newcastle-Ottawa scale were used for the methodological quality assessments of included studies. The meta-analysis was performed using the Comprehensive Meta-analysis Version 2.

RESULTS

A total of 67 patients from one RCT study, 2 prospective observational studies, and one retrospective study were included in this meta-analysis. The pooled data of the 4 included studies showed that overall VAS after the PRF treatment was significantly reduced (P ≤ .001). In the subgroup analysis according to follow-up evaluation time points, the pain was significantly reduced at 2 weeks, 1 month, 3 months, and 6 months after the procedure (2 weeks: P = .02; 1, 3, and 6 months: P < .001).

CONCLUSION

According to the results of the meta-analysis, the use of PRF on the DRG is effective for alleviating cervical radicular pain, which was unresponsive to oral medications, physical therapy, or epidural steroid injection.

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.

Lumbar Dorsal Root Ganglion Block as a Prognostic Tool Before Pulsed Radiofrequency: A Randomized, Prospective, and Comparative Study on Cost-Effectiveness

OBJECTIVES

In the study, we discuss the predictive value and cost-effectiveness of dorsal root ganglion (DRG) blocks before using dorsal root ganglion pulsed radiofrequency (DRG-PRF) in the treatment of low back pain.

METHODS

The study comprised 60 patients with low back pain who were randomly assigned into 2 groups. Patients in group 1 were screened using DRG block before DRG-PRF treatment for responders. Patients in group 2 underwent DRG-PRF treatment without DRG block. Successful outcome was defined as patient satisfaction, improvement in numerical rating scale, and medication use reduction.

RESULTS

In group 1 (n = 30), 24 patients demonstrated good response to DRG block, and 20 patients had successful outcome at 6 months after DRG-PRF therapy. In group 2 (n = 30), 25 of the patients had successful outcome at 6 months after DRG-PRF therapy. The mean medical costs were NT$ 19,245 and NT$ 16,375 for each successful case in groups 1 and 2, respectively.

CONCLUSIONS

In this comparative cost-effectiveness study, the application of diagnostic DRG blocks before DRG-PRF did not have a significant impact on patient satisfaction, pain index score, or pain medication reduction. Furthermore, the application of diagnostic DRG blocks resulted in overall greater medical costs. These findings suggest that DRG-PRF without screening by DRG block is more cost-effective and less invasive.

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

BACKGROUND

Chronic lumbosacral radicular pain is a challenging medical problem with respect to therapeutic management. Many patients with lumbosacral radicular pain complain of persistent leg pain after transforaminal epidural steroid injection. Nowadays, pulsed radiofrequency (PRF) stimulation on the dorsal root ganglion (DRG) is widely used for controlling lumbosacral radicular pain.

METHODS

We evaluated the effect of bipolar PRF on the DRG for the management of lumbosacral radicular pain. In addition, we compared the effect of bipolar PRF to monopolar PRF. Fifty patients with chronic lumbosacral radicular pain were included in the study and randomly assigned to 1 of 2 groups, the bipolar or monopolar PRF group (n = 25 per group). Pain intensity was evaluated using a numeric rating scale (NRS) at pretreatment, and 1, 2, and 3 months after treatment.

RESULTS

When compared to the pretreatment NRS scores, patients in both groups showed a significant decrease in NRS scores at 1, 2, and 3 months after treatment. Reductions in the NRS scores over time were significantly larger in the bipolar PRF group. Three months after treatment, 19 patients (76.0%) in the bipolar PRF group and 12 patients (48.0%) in the monopolar PRF group reported successful pain relief (pain relief of ≥50%).

CONCLUSION

The use of bipolar PRF on the DRG can be an effective and safe interventional technique for chronic refractory lumbosacral radiculopathy, particularly in patients whose pain are refractory to epidural steroid injection or monopolar PRF stimulation.

A comprehensive review of pulsed radiofrequency in the treatment of pain associated with different spinal conditions

OBJECTIVE

The objective of this review was to evaluate the efficacy of pulsed radiofrequency (PRF) treatment of pain associated with different spinal conditions. The mechanisms of action and biological effects are shortly discussed to provide the scientific basis for this radiofrequency modality.

METHODS

We systematically searched for clinical studies on spinal clinical conditions using PRF. We searched the MEDLINE (PubMed) database. We classified the information in one table focusing on randomized controlled trials (RCTs) and other types of studies. Date of last electronic search was October 2016.

RESULTS

We found four RCTs that evaluated the efficacy of PRF on cervical radicular pain and five observational studies. Two trials and three observational studies were conducted in patients with facet pain. For disc-related pathology, we found one RCT with PRF applied intradiscally and three RCTs for dorsal root ganglia PRF modulation lumbosacral radicular pain. For sacroiliac joint pain, spondylolisthesis, malignancies and other minor spinal pathology, limited studies were conducted.

CONCLUSION

From the available evidence, the use of PRF to the dorsal root ganglion in cervical radicular pain is compelling. With regard to its lumbosacral counterpart, the use of PRF cannot be similarly advocated in view of the absence of standardization of PRF parameters, enrolment criteria and different methods in reporting results; but, the evidence is interesting. The use of PRF in lumbar facet pain was found to be less effective than conventional RF techniques. For the other different spinal conditions, we need further studies to assess the effectiveness of PRF. Advances in knowledge: The use of PRF in lumbar facet pain was found to be less effective than conventional RF techniques. For the other different spinal conditions, we need further studies to assess the effectiveness of PRF.

Percutaneous Cervical Nucleoplasty vs. Pulsed Radio Frequency of the Dorsal Root Ganglion in Patients with Contained Cervical Disk Herniation; A Prospective, Randomized Controlled Trial

BACKGROUND

Cervical neck pain is often caused by cervical disk pathology and may cause severe symptoms and disability. Surgeons and patients are increasingly aware of postsurgery-related complications. This stimulated the clinical usage of minimally invasive treatments such as percutaneous nucleoplasty (PCN) and pulsed radio frequency (PRF). However, scientific evidence on both treatments is limited.

OBJECTIVE

Our objective was to evaluate the efficacy of PCN compared to PRF in patients with contained cervical disk herniation.

METHODS

A prospective randomized clinical trial was conducted including 34 patients with radicular pain due to a single contained cervical disk herniation who were treated with either PCN or PRF. Demographic data were collected, and the Medical Outcomes Study 12-Item Short Form (SF-12) Health Survey, visual analog scale (VAS), and the Neck Disability Index (NDI) were completed 1, 2, and 3 months after treatment. Treatment satisfaction and complications were recorded.

RESULTS

In the PCN group (n = 17, mean age 52.4 years, 10 female/7 male), patients were treated at C5 to C6 (8 cases) or C6 to C7 (9 cases). In the PRF group (n = 17, mean age 49.5 years, 8 female/9 male), patients were treated at C3 to C4 (1 case), C5 to C6 (10 cases), or C6 to C7 (6 cases). At 3 months, mean pain VAS improved significantly from baseline in the PCN group (mean improvement: 43.4 points) and in the PRF group (34.0 points). However, improvement in 1 group was not superior compared to the other group (P = 0.48). No serious complications were reported.

CONCLUSION

Within 3 months, both PCN and PRF show significant pain improvement in patients with contained cervical disk herniation, but none is superior to the other. Both treatment options appear to be effective and safe in regular clinical practice.

A Randomized Comparative Study of Pulsed Radiofrequency Treatment With or Without Selective Nerve Root Block for Chronic Cervical Radicular Pain

BACKGROUND

We demonstrated a combination of pulsed radiofrequency (PRF) and cervical nerve root block (CNRB) via a posterior approach was superior to a transforaminal epidural steroid injection through the anterolateral approach for cervical radicular pain in a previous study. This randomized trial was conducted to determine the comparative efficacy between CNRB, PRF, and CNRB + PRF for cervical radicular pain.

METHODS

A prospective and randomized design was used in this study. Sixty-two patients were randomized into three parallel groups: CNRB, PRF, or CNRB + PRF. Numeric Rating Scale (NRS) was used to measure pain intensity, and global perceived effect (GPE) was scored by the patient on a 7-point scale, ranging from much worse (-3), no change (0), to total improvement (+3). The outcomes were evaluated at 1 week, 1 month, 3 months, and 6 months. Side effects and complications were noted.

RESULTS

The NRS was significantly reduced in all three groups 1 week after the treatments (P < 0.001), and the rates of positive GPE (+2 or +3) were not significantly different between the three groups. At 1, 3, and 6 months of follow-ups, the combined therapy achieved significantly lower NRS and higher GPE compared to CNRB or PRF alone group (P < 0.001). There were no significant differences between the CNRB and PRF groups (P > 0.05). No serious complications were observed in any of the patients.

CONCLUSIONS

Combining CNRB and PRF appeared to be a safe and efficacious technique for cervical radicular pain. The combination therapy yielded better outcomes than either CNRB or PRF alone.

Comparative effectiveness of lumbar epidural steroid injections using particulate vs. non-particulate steroid: an intra-individual comparative study

OBJECTIVES

To perform an intra-individual comparison for the effectiveness of lumbar epidural steroid injection (ESI) between injections using particulate (triamcinolone) and non-particulate (dexamethasone) steroid.

MATERIALS AND METHODS

This study included 162 patients(M:F = 60:102, mean age 66.3 years) who underwent lumbar ESI using dexamethasone(ESI_DEXA) from April 2013 to May 2013 and who had previously underwent lumbar ESI using triamcinolone(ESI_TRIAM) within 1 year. Degree of relative satisfaction, injection-free interval and injection frequency were determined. Subgroup analyses were also done according to the diagnosis, approach-methods, patients' ages and sex.

RESULTS

Eighty-seven of 139 patients (62.6 %) responded that the effect of ESI_TRIAM was better than that of ESI_DEXA (p = 0.004). In the four subgroups-patients with herniated intervertebral disc (HIVD), who underwent transforaminal ESI, were under age 70 and were male patients-the proportion of patients who preferred ESI_TRIAM was significantly greater than the proportion patients who preferred ESI_DEXA in terms of relative satisfaction (p < 0.05). The injection-free interval of ESI_TRIAM was significantly longer than that of ESI_DEXA (p = 0.01). In the subgroup analyses, the patient groups HIVD, who underwent transforaminal ESI, under age 70 and female patients with longer injection-free interval of ESI_TRIAM than ESI_DEXA were statistically significant (p < 0.05). Other factors were not significant.

CONCLUSION

The relative satisfaction with ESI_TRIAM was significantly better than that with ESI_DEXA in the same patient, and the injection-free interval after ESI_TRIAM was significantly longer than that after ESI_DEXA.

Radiofrequency for the Treatment of Lumbar Radicular Pain: Impact on Surgical Indications

Study Design. Quasiexperimental study. Objective. To investigate whether radiofrequency treatment can preclude the need for spinal surgery in both the short term and long term. Background. Radiofrequency is commonly used to treat lumbosacral radicular pain. Only few studies have evaluated its effects on surgical indications. Methods. We conducted a quasiexperimental study of 43 patients who had been scheduled for spinal surgery. Radiofrequency was indicated for 25 patients. The primary endpoint was the decision of the patient to reject spinal surgery 1 month and 1 year after treatment (pulsed radiofrequency of dorsal root ganglion, 76%; conventional radiofrequency of the medial branch, 12%; combined technique, 12%). The primary endpoint was the decision of the patient to reject spinal surgery 1 month and 1 year after treatment. In addition, we also evaluated adverse effects, ODI, NRS. Results. We observed after treatment with radiofrequency 80% of patients rejected spinal surgery in the short term and 76% in the long term. We conclude that radiofrequency is a useful treatment strategy that can achieve very similar outcomes to spinal surgery. Patients also reported a very high level of satisfaction (84% satisfied/very satisfied). We also found that optimization of the electrical parameters of the radiofrequency improved the outcome of this technique.

The appropriate use of neurostimulation of the spinal cord and peripheral nervous system for the treatment of chronic pain and ischemic diseases: the Neuromodulation Appropriateness Consensus Committee

INTRODUCTION

The Neuromodulation Appropriateness Consensus Committee (NACC) of the International Neuromodulation Society (INS) evaluated evidence regarding the safety and efficacy of neurostimulation to treat chronic pain, chronic critical limb ischemia, and refractory angina and recommended appropriate clinical applications.

METHODS

The NACC used literature reviews, expert opinion, clinical experience, and individual research. Authors consulted the Practice Parameters for the Use of Spinal Cord Stimulation in the Treatment of Neuropathic Pain (2006), systematic reviews (1984 to 2013), and prospective and randomized controlled trials (2005 to 2013) identified through PubMed, EMBASE, and Google Scholar.

RESULTS

Neurostimulation is relatively safe because of its minimally invasive and reversible characteristics. Comparison with medical management is difficult, as patients considered for neurostimulation have failed conservative management. Unlike alternative therapies, neurostimulation is not associated with medication-related side effects and has enduring effect. Device-related complications are not uncommon; however, the incidence is becoming less frequent as technology progresses and surgical skills improve. Randomized controlled studies support the efficacy of spinal cord stimulation in treating failed back surgery syndrome and complex regional pain syndrome. Similar studies of neurostimulation for peripheral neuropathic pain, postamputation pain, postherpetic neuralgia, and other causes of nerve injury are needed. International guidelines recommend spinal cord stimulation to treat refractory angina; other indications, such as congestive heart failure, are being investigated.

CONCLUSIONS

Appropriate neurostimulation is safe and effective in some chronic pain conditions. Technological refinements and clinical evidence will continue to expand its use. The NACC seeks to facilitate the efficacy and safety of neurostimulation.

The efficacy of pulsed radiofrequency treatment of cervical radicular pain patients

Objective

Cervical radicular pain is defined as pain arising in the arm caused by irritation of a cervical spinal nerve or its roots. Although many treatment modalities are described in the literature, the available evidence for efficacy is not sufficient to allow definitive conclusions. The goal of this study was to establish the benefits and prognostic factors of pulsed radiofrequency (PRF) on the adjacent cervical dorsal root ganglia (DRG) of cervical radicular pain patients.

Methods

A retrospective study of PRF treatment of patients with cervical radicular pain was carried out. Two times diagnostic block of cervical DRG were performed before PRF. PRF was applied for 2 minutes at a setting of 2 Hz and 45 V by two times on the same targets, with the end point being an electrode tip temperature 42℃. Numerical rating scale (NRS) score was evaluated post-treatment 2 week, 1 month, 3 months and 6 months, which were compared with pretreatment value. A successful outcome was defined that NRS change was improved more than 50% at 6 months.

Results

The mean age was 54 years. The success rate was 68%(15/22) after six months of follow-up. PRF induced complications were not observed. Between success and failure group, we do not find any positive outcome prognostic factor. Interestingly, PRF treatment on foraminal stenosis is better outcome than herniated cervical disc.

Conclusion

PRF on adjacent cervical DRG is effective and safe treatment option for cervical radicular pain patients. However, more long-term follow up and larger patients are needed to establish effectiveness PRF treatment on cervical radicular pain patients.

Minimally invasive surgery with spotlight work channel system in the treatment of lumbar disc herniation: a retrospective study of 21 cases

A group of lumbar discherniation cases was treated with posterior discectomy and decompression with Spotlight working channel. We retrospectively studied these patients. To study and analyze the clinical efficacy and technical features of discectomy which is carried out with the Spotlight channel technology. The development of the minimally invasive spine surgery technology promotes new instruments and materials. For minimally invasive spine surgery in channel technology, the newly launched Depuy(Spine) working channel-Spotlight, which is a new generation of wide viewing angle, single-hole device for minimally invasive spine operations, has good prospects for clinical application. From March 2011 to March 2012, 21 patients who were diagnosed with lumbar disc herniation were treated with posterior discectomy and decompression with Spotlight working channel, then the lumbar and leg pain visual analogue scale (VAS) scores of before and after surgery and that of the follow-ups and the Oswestry Disability Index were analyzed. All patients were successfully operated, and also they received follow-ups for more than 1 year. The postoperative lumbar and leg pain VAS scores improved significantly compared with the preoperative ones (P < 0.05) and can effectively maintain (P > 0.05). The three time points of lumbar pain VAS were 7.80 ± 0.49, 1.51 ± 0.52 and 1.47 ± 0.59. The leg pain VAS were 7.53 ± 0.50, 1.58 ± 0.58 and 1.49 ± 0.67. During the follow-ups of the cases in this group, no case of disc herniation relapsed. Patients were satisfied with that. The Spotlight channel system is one of the surgical approaches to "minimally invasive spine technology with direct vision". It has a good range of surgical indications. It can be carried out flexibly and used widely, which means it will be easier for the surgeons to master.

Pulsed radiofrequency treatment of the lumbar dorsal root ganglion in patients with chronic lumbar radicular pain: a randomized, placebo-controlled pilot study

Background

No proof of efficacy, in the form of a randomized controlled trial (RCT), exists to support pulsed radiofrequency (PRF) treatment of the dorsal root ganglion (DRG) for chronic lumbar radicular (CLR) pain. We determined the feasibility of a larger trial (primary objective), and also explored the efficacy of PRF in decreasing pain on a visual analog scale (VAS) and improving the Oswestry Disability Index.

Methods

This was a single-center, placebo-controlled, triple-blinded RCT. Patients were randomized to a placebo group (needle placement) or a treatment group (PRF at 42°C for 120 seconds to the DRG). Patients were followed up for 3 months post procedure. Outcomes with regard to pain, Oswestry Disability Index score, and side effects were analyzed on an intention-to-treat basis.

Results

Over 15 months, 350 potential patients were identified and 56 were assessed for eligibility. Fifteen of them did not meet the selection criteria. Of the 41 eligible patients, 32 (78%) were recruited. One patient opted out before intervention. Three patients were lost to follow-up at 3 months. Mean VAS differences were not significantly different at 4 weeks (−0.36, 95% confidence interval [CI], −2.29, 1.57) or at 3 months (−0.76, 95% CI, −3.14, 1.61). The difference in mean Oswestry Disability Index score was also not significantly different at 4 weeks (−2%, 95% CI, −14%, 10%) or 3 months (−7%, 95% CI, −21%, 6%). There were no major side effects. Six of 16 patients in the PRF group and three of 15 in the placebo group showed a >50% decrease in VAS score.

Conclusion

The recruitment rate was partially successful. At 3 months, the relative success of PRF-DRG was small. A large-scale trial to establish efficacy is not practically feasible considering the small effect size, which would necessitate recruitment of a challengingly large number of participants over a number of years. Until clear parameters for application of PRF are established, clinicians will need to use their individual judgment regarding its clinical applicability, given the present evidence.

A systematic review: current and future directions of dorsal root ganglion therapeutics to treat chronic pain

OBJECTIVE

The purpose of the study was to systematically review the historical therapeutics for chronic pain care directed at the dorsal root ganglion (DRG) and to identify future trends and upcoming treatment strategies.

METHODS

A literature search on bibliographic resources, including EMBASE, PubMed Cochrane Database of Systemic Reviews from literature published from 1966 to December 1, 2012 to identify studies and treatments directed at the DRG to treat chronic pain, and was limited to the English language. Case series, case reports, and preclinical work were excluded. Information on emerging technologies and pharmacologics were captured separately, as they did not meet the inclusion criteria.

RESULTS

The literature review yielded three current clinical treatment strategies: ganglionectomy, conventional radiofrequency treatment of the dorsal root ganglion, and pulsed radiofrequency treatment of the DRG. Seven studies were identified utilizing ganglionectomy, 14 for conventional radiofrequency, and 16 for pulsed radiofrequency. Electrical stimulation and novel therapeutic delivery strategies have been proposed and are in development.

CONCLUSIONS

Despite a robust understanding of the DRG and its importance in acute nociception, as well as the development and maintenance of chronic pain, relatively poor evidence exists regarding current therapeutic strategies. Novel therapies like electrical and pharmacologic strategies are on the horizon, and more prospective study is required to better qualify the role of the DRG in chronic pain care.

Evaluation of pulsed electromagnetic field therapy in the management of patients with discogenic lumbar radiculopathy

AIM

This randomized clinical trial was designed to evaluate the effect of pulsed electromagnetic field therapy (PEMF) in the management of patients with discogenic lumbar radiculopathy.

METHODS

Forty patients suffering from lumbar radiculopathy due to lumbar disc prolapse were randomly assigned to one of two groups: a study group that included 20 patients who received PEMF therapy and a control group that included 20 patients who received placebo treatment. Both groups were evaluated at bases line and after 3 weeks by using a visual analogue scale (VAS) (0-10), somatosensory evoked potentials (SSEPs) for selected dermatomes and Modified Oswestry Low Back Pain Disability Questionnaire (OSW), and findings were compared before and after treatment.

RESULTS

Significant differences were observed between both groups before and after application of PEMF therapy relative to VAS (P=0.024), total OSW (P<0.001), and other domains of OSW score (pain intensity [P=0.009], personal care [P=0.01], lifting [P<0.001], walking [P<0.001], sitting [P<0.001], standing [P<0.001], sleeping [P<0.001], social life [P<0.001] and employment [P=0.003]). Other significant differences were observed between both groups relative to SSEP latency and amplitude of the evaluated dermatomes on the right side (P=0.022 and P=0.001, respectively), and left side latency and amplitude (P=0.016 and P=0.002, respectively).

CONCLUSION

PEMF therapy is an effective method for the conservative treatment of lumbar radiculopathy caused by lumbar disc prolapse. In addition to improvement of clinically observed radicular symptoms, PEMF also seems effective in reducing nerve root compression as evidenced by improvement of SSEP parameters after treatment.

Changes in pain behavior and glial activation in the spinal dorsal horn after pulsed radiofrequency current administration to the dorsal root ganglion in a rat model of lumbar disc herniation: laboratory investigation

OBJECT

Herniated discs can induce sciatica by mechanical compression and/or chemical irritation caused by proinflammatory cytokines. Using immunohistochemistry methods in the dorsal horn of a rat model of lumbar disc herniation, the authors investigated the effects of pulsed radiofrequency (PRF) current administration to the dorsal root ganglion (DRG) on pain-related behavior and activation of microglia, astrocytes, and mitogen-activated protein kinase.

METHODS

A total of 33 Sprague-Dawley rats were randomly assigned to either a sham-operated group (n = 10) or a nucleus pulposus (NP)-exposed group (n = 23). Rats in the NP-exposed group were further subdivided into NP exposed with sham stimulation (NP+sham stimulation, n = 10), NP exposed with PRF (NP+PRF, n = 10), or euthanasia 10 days after NP exposure (n = 3). The DRGs in the NP+PRF rats were exposed to PRF waves (2 Hz) for 120 seconds at 45 V on postoperative Day 10. Rats were tested for mechanical allodynia 10 days after surgery and at 8 hours, 1 day, 3 days, 10 days, 20 days, and 40 days after PRF administration. Immunohistochemical staining of astrocytes (glial fibrillary acidic protein), microglia (OX-42), and phosphorylated extracellular signal-regulated kinases (pERKs) in the spinal dorsal horn was performed at 41 days after PRF administration.

RESULTS

Starting at 8 hours after PRF administration, mechanical withdrawal thresholds dramatically increased; this response persisted for 40 days (p < 0.05). After PRF administration, immunohistochemical expressions of OX-42 and pERK in the spinal dorsal horn were quantitatively reduced (p < 0.05).

CONCLUSIONS

Pulsed radiofrequency administration to the DRG reduced mechanical allodynia and downregulated microglia activity and pERK expression in the spinal dorsal horn of a rat model of lumbar disc herniation.

[Long-term effects of interventional treatment on chronic pain of the musculoskeletal system. Retrospective outcome study of repeated in-patient treatment]

INTRODUCTION

Interventional procedures are frequently used for treatment of musculoskeletal pain syndromes but current scientific evidence does not show successful outcome in chronic cases. In this study the effect of repeated interventional treatment on the long-term outcome of patients with chronic musculoskeletal pain was examined.

MATERIALS AND METHODS

In order to prepare for a retrospective outcome study (RCT) on proliferation therapy the clinical records of 38 patients who had been repeatedly treated (minimum 5 times) with an interventional treatment concept were examined.

RESULTS

Patients were treated on average 10 times with approximately 107 single injections during each treatment cycle. In the long term the chronic pain syndrome showed a statistically significant deterioration with a generalization of the pain as well as an increase in pain medication, surgery and psychosocial impairment..

DISCUSSION

Repeated treatment cycles of interventional pain therapy did not lead to an improvement in the treated pain syndromes and in the long term the pain syndromes deteriorated further. It seems likely that the interventional approach promoted this adverse development but the data of this study are not sufficient to conclusively prove this thesis.

Assessing the effectiveness of 'pulse radiofrequency treatment of dorsal root ganglion' in patients with chronic lumbar radicular pain: study protocol for a randomized control trial

Background

Chronic lumbar radicular pain can be described as neuropathic pain along the distribution of a particular nerve root. The dorsal root ganglion has been implicated in its pathogenesis by giving rise to abnormal impulse generation as a result of irritation, direct compression and sensitization. Chronic lumbar radicular pain is commonly treated with medications, physiotherapy and epidural steroid injections. Epidural steroid injections are associated with several common and rarer side effects such as spinal cord infarction and death. It is essential and advantageous to look for alternate interventions which could be effective with fewer side effects.

Pulse radio frequency is a relatively new technique and is less destructive then conventional radiofrequency. Safety and effectiveness of pulse radio frequency in neuropathic pain has been demonstrated in animal and humans studies. Although its effects on dorsal root ganglion have been studied in animals there is only one randomized control trial in literature demonstrating its effectiveness in cervical radicular pain and none in lumbar radicular pain. Our primary objective is to study the feasibility of a larger trial in terms of recruitment and methodology. Secondary objectives are to compare the treatment effects and side effects.

Methods/designs

This is a single-center, parallel, placebo-controlled, triple-blinded (patients, care-givers, and outcome assessors), randomized control trial. Participants will have a history of chronic lumbar radicular pain for at least 4 months in duration. Once randomized, all patients will have an intervention involving fluoroscopy guided needle placement to appropriate dorsal root ganglion. After test stimulation in both groups; the study group will have a pulse radio frequency treatment at 42°C for 120 s to the dorsal root ganglion, with the control group having only low intensity test stimulation for the same duration. Primary outcome is to recruit at least four patients every month with 80% of eligible patients being recruited. Secondary outcomes would be to assess success of intervention through change in the visual analogue scale measured at 4 weeks post intervention and side effects. Allocation to each group will be a 1:1 ratio with allocation block sizes of 2, 4, and 6.

Trial registration

ClinicalTrials.gov NCT01117870

Long-term effect of pulsed radiofrequency on chronic cervical radicular pain refractory to repeated transforaminal epidural steroid injections

OBJECTIVE

The article aims to evaluate the long-term effectiveness and safety of pulsed radiofrequency (PRF) on the dorsal root ganglion (DRG) in patients with chronic cervical radicular pain refractory to repeated transforaminal epidural steroid injections (TFESIs).

DESIGN

This is a prospective observational study.

METHODS

We retrospectively reviewed data on 112 subjects who had received repeated TFESIs for cervical radicular pain. Twenty-nine of those 112 patients continued to complain of persistent cervical radicular pain, despite an average of three repeated TFESIs. Among 29 patients with sustained arm pain of over 4 on the numerical rating scale (NRS), a total of 21 patients were included prospectively. Those 21 patients underwent PRF on the symptomatic cervical DRG and were evaluated carefully for neurologic deficits and side effects. The clinical outcomes were measured via NRS for arm pain before treatment, and 1, 3, 6, and 12 months after treatment. Successful pain relief was defined as a 50% or more reduction in the NRS score as compared with the pretreatment score. After 12 months, patients' satisfaction levels with treatment were determined.

RESULTS

Fourteen of the 21 patients (66.7%) after cervical PRF stimulation reported pain relief of 50% or more at the 3-month and 12-month follow-up periods, respectively. Fifteen of the 21 patients (71.4%) were satisfied with their outcome at 12 months' posttreatment. No serious adverse effects were observed.

CONCLUSION

Application of PRF to the DRG appears to be an effective and relatively safe intervention technique for chronic cervical radicular pain refractory to repeated TFESIs.

Treatment experience of pulsed radiofrequency under ultrasound guided to the trapezius muscle at myofascial pain syndrome -a case report-

Trigger point injection treatment is an effective and widely applied treatment for myofascial pain syndrome. The trapezius muscle frequently causes myofascial pain in neck area. We herein report a case in which direct pulsed radiofrequency (RF) treatment was applied to the trapezius muscle. We observed that the RF treatment produced continuous pain relief when the effective duration of trigger point injection was temporary in myofascial pain.

Short-term effects of pulsed radiofrequency on chronic refractory cervical radicular pain

OBJECTIVE

To evaluate the short-term effectiveness of pulsed radiofrequency on the dorsal root ganglion (DRG) in patients with chronic refractory cervical radicular pain.

METHOD

Fifteen patients (13 males, 2 females; mean age, 55.9 years) with chronic radicular pain due to cervical disc herniation or foraminal stenosis refractory to active rehabilitative management, including transforaminal cervical epidural steroid injection and exercise, were selected. All patients received pulsed radiofrequency on the symptomatic cervical dorsal root ganglion and were carefully evaluated for neurologic deficits and side effects. The clinical outcomes were measured using a visual analogue scale (VAS) and a neck disability index (NDI) before treatment, one and three months after treatment. Successful pain relief was defined as a 50% or greater reduction in the VAS score as compared with the pre-treatment score. After three months, we categorized the patients' satisfaction.

RESULTS

The average VAS for radicular pain was reduced significantly from 5.3 at pretreatment to 2.5 at 3 months post-treatment (p<0.05). Eleven of 15 patients (77.3%) after cervical pulsed RF stimulation reported pain relief of 50% or more at the 3 month follow-up. The average NDI was significantly reduced from 44.0% at pretreatment to 35.8% 3 months post-treatment (p<0.05). At 3 months post-treatment, eleven of fifteen patients (73.3%) were satisfied with their status. No adverse effects were observed.

CONCLUSION

The results demonstrate that the application of pulsed radiofrequency on DRG might be an effective short-term intervention for chronic refractory cervical radicular pain. Further studies, including a randomized controlled trial with long-term follow-up, are now needed.

Pulsed radiofrequency treatment adjacent to the lumbar dorsal root ganglion for the management of lumbosacral radicular syndrome: a clinical audit

INTRODUCTION

Lumbosacral radicular syndrome (LRS) is probably the most frequent neuropathic pain syndrome. Three months to 1 year after onset, 30% of the patients still experience ongoing pain. The management of those patients is complex, and treatment success rates are rather low. The beneficial effect of pulsed radiofrequency (PRF) therapy has been described for the treatment of LRS in case reports and in retrospective and prospective studies. Up until now, no neurological complications have been reported after PRF treatment. The current clinical audit has been performed to assess the amount of pain relief after a single PRF treatment.

METHODS

Sixty consecutive patients who received a PRF treatment adjacent to the lumbar dorsal root ganglion for the management of LRS in the period 2007-2009 were included. The main study objective was to measure the reduction of pain after the pulsed radiofrequency treatment by using the global perceived effect. The primary end point was defined as at least 50% pain relief for a period of 2 months or longer.

RESULTS

The primary end point was achieved in 29.5% of all the PRF interventions. After 6 months, 50% pain relief was still present in 22.9% of the cases and after 12 months in 13.1% of the cases. The need for pain medication was significantly lower after pulsed radiofrequency treatment in the success group compared with the nonsuccess group.

CONCLUSIONS

PRF treatment can be considered for the management of LRS patients. These results need to be confirmed in a randomized clinical trial.

Application of pulsed radiofrequency currents to rat dorsal root ganglia modulates nerve injury-induced tactile allodynia

BACKGROUND

Application of pulsed radiofrequency (PRF) currents to the dorsal root ganglia (DRG) has been reported to produce relief from certain pain states without causing thermal ablation. In this study, we examined the direct correlation between PRF application to DRG associated with spinal nerve injury and reversal of injury-induced behavioral hypersensitivity in a rat neuropathic pain model.

METHODS

Neuropathic lesioning was performed via left L5 spinal nerve ligation on male adult Sprague-Dawley rats. Once the injured rats had developed tactile allodynia, one group was then assigned to PRF treatment of the L5 DRG and another group was assigned to the sham treatment to the DRG. Behavioral testing was performed on both the control and treated paws using the von Frey filament test before the surgery and at indicated days. The resulting data were analyzed using a linear mixed model to assess the overall difference between the treatment groups and the overall difference among the study days. Cohen's d statistic was computed from paired difference-from-baseline scores for each of the 14 study days after treatment and these measures of effect size were then used to descriptively compare the recovery patterns over time for each study group.

RESULTS

Spinal nerve injury resulted in the development of behavioral hypersensitivity to von Frey filament stimulation (allodynia) in the hindpaw of the left (injury) side. Mixed linear modeling showed a significant difference between the treatment groups (P = 0.0079) and a significant change of paw withdrawal threshold means over time (P = 0.0006) for all 12 animals. Evaluation of Cohen's d (effect size) revealed that the PRF-treated animals exhibited better recovery and recorded larger effect sizes than the sham-treated animals on 10 of the 14 post-PRF treatment days and exhibited moderate-to-strong effects posttreatment at days 8 to 10 and at and beyond day 32.

CONCLUSIONS

Findings from this study support that PRF of the DRG causes reversal of nerve injury (spinal nerve ligation)-induced tactile allodynia in rats. This allodynia reversal indicates that nonablative PRF acting via modulation of the DRG can speed recovery in nerve injury-induced pain.

Radiofrequency ablation technique eradicating palpebral margin neoplasm

AIM

To report the study on radiofrequency ablation technique for eradication of palpebral margin neoplasm and its clinical effects.

METHODS

One hundred and six cases with the palpebral margin neoplasm were performed surgical removal with radiofrequency ablation technique. The 1-2 months postoperative follow-up was investigated and the lost cases were excluded from statistics. The continuing follow-up lasted about 6-16months.

RESULTS

One hundred cases underwent one treatment and 6 cases underwent two treatments. Six cases were missed. All the cases followed up healed well without pigmentation or scar left, nor eyelash loss or palpebral margin deformation. No case was recurrent.

CONCLUSION

Radiofrequency ablation has significant efficiency in eradicating the palpebral margin neoplasm.