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

Efficacy of Ultrasound-Guided Transverse Abdominal Plane Block for Residual Pain After Pulsed Radiofrequency in Abdominal Acute/Subacute Herpes Zoster-Related Pain

BACKGROUND

Pulse radiofrequency (PRF) can reduce the persistent pain of herpes zoster (HZ), but some patients still have residual pain and do not achieve satisfactory results. This study aimed to assess the efficacy of PRF combined with transverse abdominal plane (TAP) block for abdominal acute/subacute HZ-related pain.

METHODS

A total of 137 acute/sub-acute HZ patients with successful PRF treatment were recruited from the Pain Department of Wuhan No. 1 Hospital between January 2018 and January 2020. There were two groups: the transversus abdominis plane group (TAP group, n = 64) and the normal saline group (NS group, n = 60). Pain intensity, sleep quality, and quality of life were quantified using the visual analogue scale (VAS), the five-item questionnaire and scoring system, and the 36-item Short Form Health Survey (SF-36) questionnaire, respectively. Follow-up assessments were conducted at baseline, 1 day, 3 months, 6 months, and 12 months after the block therapy.

RESULTS

Compared to the NS group, the TAP group showed significantly decreased pain scores 1 day, 3 months, 6 months, and 12 months after block therapy (P < .05). The sleep quality scores were lower in the TAP group than that in the NS group at 6 months (5.0 ± 2.4 vs 6.3 ± 3.7, p = .042), and 12 months after therapy (3.1 ± 1.8 vs 4.1 ± 2.4, p = .031). For quality of life, in comparison to NS group participants, those in the TAP group exhibited significantly higher scores (p < .05) for quality of life at 3 months, 6 months, and 12 months follow-up. There was a significant decrease in the proportion of pregabalin and analgesic medications in the TAP group and NS group at 6 and 12 months after treatment compared to Baseline (p < .001). Furthermore, the results showed that there was a significant difference in VAS, sleep quality scores (SQS), and quality of life between the PRF + TAP group and pharmacological therapies group before and 12 months after treatment (p < .05).

CONCLUSION

The TAP block is a promising complementary treatment for acute/subacute HZ patients who have undergone PRF treatment. Combining PRF with the TAP block has the potential to alleviate HZ-related pain, enhance the patients' quality of life, and improve their sleep quality.

Effectiveness and safety of stellate ganglion block with trioxygen autologous blood retransfusion therapy for facial postherpetic neuralgia in elderly patients

This study evaluated the efficacy and safety of stellate ganglion block (SGB) combined with trioxygen autologous blood retransfusion therapy (TABRT) in treating postherpetic neuralgia (PHN) of the head and face in elderly patients. A total of 190 patients (aged ≥ 60 years) with PHN were randomly assigned to receive either drug treatment alone (Group D, n = 40), drug treatment with SGB (Group DS, n = 52), drug treatment with TABRT (Group DT, n = 53), or drug combined SGB with TABRT (Group DST, n = 45). Key outcomes included pain visual analogue scale (VAS) scores and anxiety levels at baseline, 7 days, and 15 days post-treatment, the need for salvage analgesics, and complication rates assessed. All groups showed significant improvements in pain and anxiety, with greater reductions in the DS, DT, and DST groups compared to the drug-only group, and the combined therapy (DST) showing the most pronounced benefits. The DST group also had the highest proportion of patients not requiring rescue analgesics and the highest complete remission rate. Overall, the combination of SGB and TABRT was found to be effective and safe, offering superior therapeutic outcomes compared to single therapies for elderly patients with PHN of the head and face.

Observation on the effect of platelet-rich plasma combined with drugs in the treatment of herpes zoster neuralgia

PURPOSE

To observe the effect of ultrasound-guided platelet-rich plasma (PRP) injection in the treatment of herpes zoster neuralgia (HZN).

METHODS

Eighty patients with HZN were randomly divided into observation group and control group, with 40 cases in each group. The observation group was treated with ultrasound-guided PRP injection of target nerves combined with drugs. The control group was treated with drugs alone. The pain scores of before treatment (T0), and 1 week (T1), 1 month (T2), 3 months (T3) and 6 months (T4) after treatment were recorded with Numerical Rating Scale (NRS). The sleep quality of patients was assessed with the Athens Insomnia Scale, and the dosage used at each time point, skin lesions, adverse reactions, and the occurrence of postherpetic neuralgia (PHN) were recorded.

RESULTS

The NRS score of the two groups after treatment showed a downward trend. Compared with T0 at each time point, the difference was statistically significant (p < 0.05). And the NRS score of the observation group was lower than control group (p < 0.05). The sleep quality of the observation group was better. The dosage of the observation group was less, and the time of herpes dry-up, scab crusting and shedding in the observation group was significantly shorter (p < 0.05). The incidence of dizziness, lethargy, ataxia and PHN in the observation group was significantly reduced (p < 0.05).

CONCLUSION

Compared with traditional drug treatment alone, the ultrasound-guided PRP injection has the advantages of better analgesia and fewer side effects, which provides a new idea for the treatment of HZN.

Comparing the efficacy and safety of high-voltage and standard-voltage pulsed radiofrequency for the treatment of postherpetic neuralgia: A pooled analysis from randomized controlled trials

Postherpetic neuralgia (PHN) is one of the most common and serious complications of herpes zoster infection. Pulsed radiofrequency (PRF) therapy has emerged to be a neuromodulation technique for the treatment of PHN. Two therapeutic options are available for PRF, including high-voltage and standard-voltage PRF. Some studies suggested that the former one had better clinical efficacy than the latter one. For the first time, this pooled analysis compared the efficacy and safety of these two surgeries for the treatment of PHN. Five commonly used databases were applied to identify the eligible studies. This study was registered on the PROSPERO (ID: CRD42023460236), which provided more relevant information. Finally, four randomized controlled trials (RCTs) with 285 participants were included. The combined odds ratios (OR) showed that high-voltage PRF exhibited a significantly higher treatment efficiency than the standard PRF (OR = 1.4, 95%CI: 1.16 to 1.69, P < 0.001). Additionally, the visual analogue scale (VAS) in the high-voltage PRF group was significantly lower than that of the standard PRF group at one week (SMD = -0.776, 95%CI: -1.408 to -0.145, P = 0.016), one month (SMD = -0.544, 95%CI: -0.907 to -0.180, P = 0.003), and three months (SMD = -1.096, 95%CI: -1.504 to -0.687, P < 0.001) after treatment, particularly at the three months after surgery. However, the VAS was comparable between the two groups (SMD = -0.94, 95%CI: -1.985 to 0.104, P = 0.077). Patients who underwent high-voltage PRF did not have a significantly higher incidence of adverse events than those with standard PRF (OR = 1.56, 95%CI: 0.78 to 3.13, P = 0.208). In summary, the current study revealed that high-voltage PRF is superior to standard-voltage PRF in improving analgesic efficacy in patients with PHN. Additionally, it does not increase the incidence of treatment-related adverse effects. Further studies are still warranted to determine the optimal voltage and duration of PRF treatment for patients with PHN.

Combined Therapy of Paravertebral Nerve Pulsed Radiofrequency and Subcutaneous Block for Acute/Subacute Herpetic Neuralgia: A Retrospective Study

OBJECTIVES

This retrospective study aimed to investigate the effectiveness and safety of early combined therapy with CT-guided paravertebral nerve (PVN), pulsed radiofrequency (PRF), and subcutaneous block on acute/subacute herpes zoster (HZ).

METHODS

A total of 98 medical records were analyzed. All patients underwent CT-guided PRF on PVN immediately followed by a single subcutaneous block with lidocaine and dexamethasone in acute/subacute phase. The therapy efficacy was evaluated by pain numeric rating scale (NRS) and effective rate, which was defined as a percent of cases with a reduction in pain NRS>50% at day 1, week 2, 4, 12, and 24 after the procedure. The incidences of medication reduction and postherpetic neuralgia (PHN) were also retrieved. Further comparison was conducted between acute group (disease duration<30 days from HZ onset) and subacute group (30 day

RESULTS

Early combined therapy indicated an immediate and sustained improvement in pain NRS as compared with before treatment ( P <0.0001), with effective rates of 74%, 79%, 80%, 76%, and 79% at day 1, week 2, 4, 12, and 24 after procedure, respectively. At the end of follow-up, the proportion of patients with a reduction of >50% in prior medications amounted to 83% and the incidence of clinically meaningful PHN decreased to 23%. The clinical efficacy was more profound in acute group than in subacute group at every time points ( P <0.05). No severe complications occurred.

DISCUSSION

Our data revealed surprising levels of pain relief by combination therapies of PRF and subcutaneous block targeting different sites of pain pathway, thus suggesting a valuable treatment option for acute/subacute herpetic neuralgia.

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Key Words Collapse

MESH Headings

• Humans
• Retrospective Studies
• Pulsed Radiofrequency Treatment/methods
• Neuralgia/complications
• Neuralgia, Postherpetic/therapy
• Herpes Zoster/complications
• Herpes Zoster/therapy

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Grants Collapse

Affiliation(s)

Wei Zhang Departments of Day Surgery
Bin Yu Departments of Day Surgery
Zipu Jia Departments of Day Surgery
Chunmei Zhao Day Surgery and Pain Management, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China
Fang Luo Day Surgery and Pain Management, Beijing Tiantan Hospital, Capital Medical University, Beijing, PR China

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Efficacy of Paravertebral Injection of Interferon-α2b Combined with High-Voltage, Long-Term Pulsed Radiofrequency in DRG in Mitigation of Postherpetic Neuralgia: A Retrospective Study

OBJECTIVE

This investigation aims to evaluate the effectiveness of the paravertebral injection of recombinant human interferon-α2b in conjunction with high-voltage, long-term, pulsed radiofrequency (PRF) in the dorsal root ganglion for the mitigation of postherpetic neuralgia (PHN).

METHODS

This retrospective study included 84 individuals with acute PHN. The participants were divided into 3 groups. Group H was treated with interferon-α2b combined with high-voltage long-term PRF. Group C was treated with a combination of high-voltage, long-term PRF and a paravertebral injection (without recombinant human interferon-α2b), and group I was treated with interferon-α2b only. All the patients in the 3 groups were orally administered a 5-mg morphine hydrochloride quick-release tablet when a burst of pain occurred during treatment. The numerical rating scale for pain score, the interleukin-6 and galectin-3 levels, and the incidence of PHN were documented before and after therapy.

RESULTS

The pain intensity of all individuals decreased after therapy. Compared with group C, the numerical rating scale scores for group H were significantly reduced at 4, 8, and 12 weeks following therapy, and the PHN incidence was significantly lower. Compared with prior treatment, the recommended dosage of gabapentin capsules and immediate-release morphine hydrochloride tablets was reduced for group H. Compared with group C, the requirement for orally administrated gabapentin capsules and morphine hydrochloride tablets in group H was reduced significantly after treatment. No serious adverse reactions occurred in any of the 3 groups.

CONCLUSIONS

Within the context of treatment of acute PHN, the injection of interferon-α2b in conjunction with high-voltage, long-term application of PRF is more effective than PRF or the injection of interferon-α2b alone.

Effect of CT-Guided Repeated Pulsed Radiofrequency on Controlling Acute/Subacute Zoster-Associated Pain: A Retrospective Cohort Study

INTRODUCTION

Zoster-associated pain (ZAP) treatment and management is still inadequate. Repeated intervention protocol is often applied to manage ZAP. This study aimed to retrospectively investigate the effect of repeated applications of pulsed radiofrequency therapy on controlling acute/subacute ZAP.

METHODS

From March 2019 to December 2021, 150 patients with acute/subacute ZAP who underwent repeated application of pulsed radiofrequency treatment (R-PRF) and pulsed radiofrequency combined paravertebral block interventions (PRF + PVB) in the Pain Department of the affiliated Hospital of Jiaxing University were enrolled. Patients were grouped by intervention protocol and received at least 12 months of follow-up assessments using the Numerical Rating Scale score (NRSs), Pittsburg Sleep Quality Index (PSQI), Simple McGill Pain Questionnaire-2 score (SF-MPQ-2s), and follow-up interventions.

RESULTS

Both groups experienced a reduction in the incidence of clinically meaningful ZAP after the intervention therapy. In the R-PRF group, there were 36 cases of clinically meaningful ZAP within the first month post-treatment, while the PRF + PVB group had 38 cases. The incidence of clinically meaningful ZAP, as determined by multivariable generalized estimating equations, was 42.86% in the R-PRF group and 57.58% in the PRF + PVB group during the first month of follow-up. There was a significant difference in the incidence of clinically meaningful ZAP between the two groups after 1 month of treatment (adjusted odds ratio: 0.40; 95% confidence interval: 0.18-0.91; p = 0.03).

CONCLUSIONS

Both R-PRF and PRF + PVB treatments effectively relieve pain in patients with acute/subacute ZAP. However, R-PRF may have superior efficacy compared to PRF + PVB in reducing the incidence of clinically meaningful ZAP 1 month after treatment.

Pulsed radiofrequency on DRG inhibits hippocampal neuroinflammation by regulating spinal GRK2/p38 expression and enhances spinal autophagy to reduce pain and depression in male rats with spared nerve injury

Evidence indicates that microglial G protein-coupled receptor kinase 2 (GRK2) is a key regulator of the transition from acute to chronic pain mediated by microglial products via the p38 mitogen-activated protein kinase (MAPK) pathway in the spinal cord dorsal horn (SCDH). Increasing studies have shown that autophagic dysfunction in the SCDH and neuroinflammation in the hippocampus underlie NeP. However, whether GRK2/p38MAPK and autophagic flux in the SCDH and hippocampal neuroinflammation are involved in NeP and depression comorbidity has not been determined. Here, we explored the effects of high-voltage pulsed radiofrequency (PRF) (85 V-PRF; HV-PRF) to the dorsal root ganglion (DRG) on pain phenotypes in Wistar male rats with spared nerve injury (SNI) and the underlying mechanisms. The exacerbation of pain phenotypes was markedly relieved by PRF-DRG. The SNI-induced reduction in GRK2 expression, elevation of p-p38 MAPK levels in the SCDH, and increase in IL-1β and TNF-α levels in the hippocampus were reversed by PRF, which was accompanied by an increase in autophagic flux in spinal microglia. The beneficial effect of 85 V-PRF was superior to that of 45 V-PRF. In addition, the improvements elicited by 85 V-PRF were reversed by intrathecal injection of GRK2 antisense oligonucleotide, and these changes were accompanied by GRK2 downregulation and p-p38 upregulation in the SCDH, increased pro-inflammatory factor levels in the hippocampus, and excessive autophagy in spinal microglia. In conclusion, our data indicate that the application of HV-PRF to the DRG could serve as an excellent therapeutic technique for regulating neuroimmunity and neuroinflammation to relieve pain phenotypes.

Efficacy of High-Voltage Pulsed Radiofrequency in Zoster-Associated Pain: A Meta-Analysis and Systematic Review

Background

Zoster-associated pain (ZAP) is often refractory to conventional treatments and can seriously affect patients' physical and mental health. High-voltage pulsed radio frequency (H-PRF) is a new method for treating ZAP with pulse voltages above 60 V or even up to 100 V. The purpose of this paper was to conduct a systematic review and meta-analysis to evaluate the efficacy of H-PRF in the management of ZAP.

Methods

PubMed, Embase, and the Cochrane library were searched from their inception to June 2022 to identify controlled trials which evaluated the effectiveness of H-PRF compared with standard PRF and sham operations. The primary outcome was pain scores at different treatment times. The secondary outcomes included SF-36 scores, rescue analgesic dose, and side effects.

Results

We reviewed 6 randomized controlled trials involving 428 patients. There was no significant difference between the H-PRF and standard PRF pain scores at 1 week after surgery and the sham operation group at 1 month. At 1, 3, and 6 months, the H-PRF group had better pain score than the standard PRF group, and at 3 months, the pain score was better than the sham operation group. The H-PRF group showed improvement in the SF-36 score, and there were no significant complications in the H-PRF group.

Conclusions

H-PRF is an effective and safe treatment method that has better effects in relieving pain and improving the quality of life and physical and mental health. Although H-PRF provides pain relief rates comparable to those of the control group in the early stages, it remains the preferred and alternative treatment for relieving herpes zoster-related pain.

Upper limb and lower limb radiofrequency treatments in orthopaedics

Radiofrequency (RF) is a minimally invasive technique for disrupting or altering nociceptive pathways to treat musculoskeletal neuropathic and nociplastic pain. RF has been employed to treat painful shoulder, lateral epicondylitis, knee and hip osteoarthritis, chronic knee pain, Perthes disease, greater trochanteric pain syndrome, plantar fasciitis, and painful stump neuromas; it has also been employed before and after painful total knee arthroplasty and after anterior cruciate ligament reconstruction. The benefits of RF include the following:it is safer than surgery; there is no need for general anaesthesia, thereby reducing adverse effects; it alleviates pain for a minimum of 3-4 months; it can be repeatable if necessary; and it improves joint function and minimizes the need for oral pain medication. RF is contraindicated for pregnant women; unstable joints (hip, knee, and shoulder); uncontrolled diabetes mellitus; presence of an implanted defibrillator; and chronic joint infection (hip, knee, and shoulder). Although adverse events from RF are unusual, potential complications can include infection, bleeding, numbness or dysesthesia, increased pain at the procedural site, deafferentation effect, and Charcot joint neuropathy. Although there is a risk of damaging non-targeted neural tissue and other structures, this can be mitigated by performing the technique under imaging guidance (fluoroscopy, ultrasonography, and computed tomography). RF appears to be a valuable technique for alleviating chronic pain syndromes; however, firm proof of the technique's efficacy is still required. RF is a promising technique for managing chronic musculoskeletal of the limbs pain, particularly when other techniques are futile or not possible.

The Effect of CT-Guided Pulsed Radiofrequency Combined with Ozone Injection on Zoster-Associated Pain: A Retrospective Study

Purpose

Globally, the incidence of herpes zoster (HZ) is increasing, and the resulting zoster-associated pain (ZAP) severely affects the quality of life of patients. Therefore, active treatment of ZAP and prevention of postherpetic neuralgia (PHN) are very important for patients in the early stage of the disease. This retrospective observational study aimed to evaluate the effect of CT-guided pulsed radiofrequency (PRF) combined with ozone injection on zoster-associated pain.

Patients and Methods

From 2018 to 2020, 84 patients with AHN (n=28), SHN (n=32), or PHN (n=24) underwent PRF combined with ozone injection treatment after pharmacologic and conservative therapies failed. The visual analogue scale (VAS), the Pittsburgh Sleep Quality Index (PSQI), and pregabalin consumption were recorded at baseline, post-PRF, and at 1, 3, 6, and 12 months after treatment. The number of remediations performed and adverse reactions were recorded, and treatment inefficiency was calculated using a VAS score greater than 3 as the criterion.

Results

The pooled results demonstrated statistically significant decreases in VAS scores, PSQI scores and consumption of pregabalin post-PRF and at 1, 3, 6, and 12 months follow-up (P<0.05). Compared with the PHN group, both the AHN and SHN groups showed clinical and statistical improvement in VAS scores and PSQI scores and in consumption of pregabalin (P< 0.05). At 1 year after the operation, the PHN group had a significantly greater number of remediation events and greater treatment inefficiency than the other two groups. No serious adverse events were observed during the procedure or during the follow-up period.

Conclusion

CT-guided PRF combined with ozone injection is safe and effective for individuals with ZAP, and its short-term and long-term effects are significant. In a sense, early PRF combined with ozone injection is more effective.

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

OBJECTIVE

Trigeminal postherpetic neuralgia (PHN) is often refractory to treatment. Pulsed radiofrequency (PRF) neuromodulation can help in preventing PHN after herpes zoster. This study aimed to compare the efficacy and safety of two different PRF modes on gasserian ganglion neuromodulation in elderly patients with acute/subacute trigeminal herpes zoster.

MATERIALS AND METHODS

A total of 120 elderly patients with acute or subacute (within past three months) trigeminal herpes zoster were randomized to receive either a single cycle of high-voltage, long-duration PRF (HL-PRF group; N = 60) or three cycles of standard PRF (S-PRF group; N = 60). Patients were followed up for six months after treatment. Visual analog scale (VAS) pain score, 36-Item Short Form Health Survey (SF-36) score, and pregabalin at baseline and at different time points during follow-up were recorded.

RESULTS

VAS and SF-36 scores declined significantly from baseline levels in both groups (p < 0.001). The scores were significantly lower in the HL-PRF group than in the S-PRF group at some time points (p < 0.05). The mean dose of pregabalin was significantly lower in the HL-PRF group than in the S-PRF group on days 3, 14, and 28 after treatment (p < 0.05). No serious adverse events occurred in either group.

CONCLUSION

HL-PRF neuromodulation of the gasserian ganglion appears to be more effective than S-PRF for preventing PHN in the elderly.

CLINICAL TRIAL REGISTRATION

ChiCTR2000038775.

Analysis of Efficacy and Factors Associated with Reccurence After Radiofrequency Thermocoagulation in Patients with Postherpetic Neuralgia: a Long-Term Retrospective and Clinical Follow-Up Study

INTRODUCTION

Postherpetic neuralgia (PHN) is a painful condition that persists for 1 month or more after herpes zoster rash has healed. Radiofrequency thermocoagulation (RF-TC) provides analgesia by destroying the dorsal root ganglion and blocking the pain upload pathway; nonetheless, the concomitant neurological-related side effects and recurrence remain a concern.

METHODS

In this study, 228 patients with PHN in the thoracic segment treated with RF-TC of the dorsal root ganglion of the spinal nerve were included, and were followed up regularly after surgery. The numerical rating scale (NRS) scores, time to recurrence, and intraoperative and postoperative adverse events were recorded and analyzed. The Kaplan-Meier method was used to plot survival curves and calculate the cumulative effective rate and recurrence rate. Cox regression analyses were performed to identify factors associated with postoperative recurrence. Predictive models were built to assess the value of applications.

RESULTS

The NRS scores decreased in all postoperative periods compared with preoperative ones. At 10-year-follow-up, recurrence was observed in 34.6% (79/228) of patients that underwent PHN. The main postoperative complications were numbness and reduced abdominal muscle strength, which gradually decreased with time, while the abdominal muscle strength gradually recovered. No other adverse events occurred. Interval-censored multivariable Cox regression analysis demonstrated that disease course, complications, pain grade, and type of RF electrode were associated with a significantly higher risk of relapse. The main intraoperative adverse effect was a transient increase in pain during RF-TC.

CONCLUSION

CT-guided RF-TC of the dorsal root ganglion of the spinal nerve for PHN is a relatively safe and effective surgical option. Disease course, type of RF electrode, complications, and pain grade are risk factors for postoperative recurrence and can assist in clinical decision-making before the RF-CT procedure.

Efficacy and Safety of Botulinum Toxin A and Pulsed Radiofrequency on Postherpetic Neuralgia: A Randomized Clinical Trial

This study evaluated the effectiveness and safety of botulinum toxin type A (BoNT-A) and pulsed radiofrequency (RF) in the clinical treatment of postherpetic neuralgia (PHN). A total of 100 patients with PHN were randomly divided into two groups (n = 50 per group): RF group and BoNT-A group. Based on conventional drug treatment, patients were treated with either a single nerve root pulsed radiofrequency therapy or a single local subcutaneous injection of BoNT-A in the lesion area. All the patients were followed up for 24 weeks on pain scores, sleep quality, anxiety, and depression scores, etc. In the last follow-up at the end of 24 weeks postoperation, the pain scores of patients in both groups were significantly lower than those before the operation (P < 0.05), indicating that both treatments were effective against PHN; however, there was no significant difference between these two groups (P > 0.05). It is noteworthy that the subcutaneous injection of BoNT-A is relatively easy to administer and less expensive compared to RF. Therefore, we believe that the subcutaneous injection of BoNT-A is an effective and safe method for the treatment of PHN.

Update on Interventional Management of Neuropathic Pain: A Delphi Consensus of the Spanish Pain Society Neuropathic Pain Task Force

Background and Objectives: Interventional management of neuropathic pain (NP) is available to the patients who do not obtain satisfactory pain relief with pharmacotherapy. Evidence supporting this is sparse and fragmented. We attempted to summarize and critically appraise the existing data to identify strategies that yield the greatest benefit, guide clinicians, and identify areas that merit further investigation. Material and Methods: A two-round Delphi survey that involved pain clinic specialists with experience in the research and management of NP was done over an ad hoc 26-item questionnaire made by the authors. Consensus on each statement was defined as either at least 80% endorsement or rejection after the 2nd round. Results: Thirty-five and 29 panelists participated in the 1st and 2nd round, respectively. Consensus was reached in 20 out of 26 statements. There is sufficient basis to treat postherpetic neuralgias and complex regional pain syndromes with progressive levels of invasiveness and failed back surgery syndrome with neuromodulation. Radiculopathies and localized NP can be treated with peripheral blocks, neuromodulation, or pulsed radiofrequency. Non-ablative radiofrequency and non-paresthetic neuromodulation are efficacious and better tolerated than ablative and suprathreshold procedures. Conclusions: A graded approach, from least to most invasive interventions has the potential to improve outcomes in many patients with common refractory NP conditions. Preliminary promising data warrant further research on new indications, and technical advances might enhance the safety and efficacy of current and future therapies.

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.

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

Pulsed radiofrequency (PRF) therapy is one of the most common treatment options for neuropathic pain, albeit the underlying mechanism has not been hitherto elucidated. In this study, we investigated the efficacy and mechanism of PRF therapy on resiniferatoxin (RTX)-induced mechanical allodynia, which has been used as a model of postherpetic neuralgia (PHN). Adult male rats were intraperitoneally injected with a vehicle or RTX. Furthermore, PRF current was applied on a unilateral sciatic nerve in all RTX-treated rats. On both ipsilateral and contralateral sides, the paw mechanical withdrawal thresholds were examined and L4-6 dorsal root ganglia (DRG) were harvested. In the DRG of rats with RTX-induced mechanical allodynia, Na_V1.7, a voltage-gated Na⁺ channel, was upregulated following the enhancement of extracellular signal-regulated kinase phosphorylation. Early PRF therapy, which was applied 1 week after RTX exposure, suppressed this Na_V1.7 upregulation and showed an anti-allodynic effect; however, late PRF therapy, which was applied after 5 weeks of RTX exposure, failed to inhibit allodynia. Interestingly, late PRF therapy became effective after daily tramadol administration for 7 days, starting from 2 weeks after RTX exposure. Both early PRF therapy and late PRF therapy combined with early tramadol treatment suppressed Na_V1.7 upregulation in the DRG of rats with RTX-induced mechanical allodynia. Therefore, Na_V1.7 upregulation in DRG is related to the development of RTX-induced neuropathic pain; moreover, PRF therapy may be effective in the clinical management of patients with PHN via Na_V1.7 upregulation inhibition.

Short-Term Peripheral Nerve Stimulation Relieve Pain for Elder Herpes Zoster Ophthalmicus Patients: A Retrospective Study

OBJECTIVE

Ophthalmic postherpetic neuralgia (PHN) is the final stage of herpes zoster (HZ) ophthalmicus and a severe refractory neuropathic pain, thus there is no curative treatment that could alleviate pain and reduce the incidence of ophthalmic PHN now. The purpose of this study is to evaluate therapeutic efficacy of short-term peripheral nerve stimulation (PNS) for elder patients with HZ ophthalmicus.

MATERIALS AND METHODS

We performed a retrospective study from March 2015 to August 2019 in our pain department. All the HZ ophthalmicus patients underwent supraorbital nerve short-term PNS were included. The patients' data, including numeric rating scale (NRS), 36-Item short form health survey (SF-36), and analgesic consumptions, were retrospectively analyzed. Severe side effects also were recorded.

RESULTS

A total of 68 patients were enrolled in this study. The NRS scores were significantly decreased at different time points after short-term PNS compared to baseline (p < 0.001). The SF-36 scores, including general health, social function, emotional role, mental health, bodily pain, physical functioning, physical role, and vitality, were significantly improved at different time points after treatment (p < 0.001). The average dosages of tramadol and pregabalin administered (mg/d) were both significantly reduced compared to baseline (p < 0.001). There was no bleeding, infection, pain increase, and other side effects after treatment.

CONCLUSIONS

Short-term PNS is an effective and safe therapeutic alternative for elder patients with HZ ophthalmicus and could reduce the incidence of ophthalmic PHN.

Observation and measurement of applied anatomical features for thoracic intervertebral foramen puncture on computed tomography images

BACKGROUND

Thoracic intervertebral foramen puncture is the key step for interventional therapy on the thoracic nerve roots or dorsal root ganglia. The anatomical features of the thoracic spine are complex, and puncture injury to the pleura, blood vessels, spinal cord, and other tissues may cause serious complications. The spatial anatomical characteristics and related parameters for thoracic intervertebral foramen puncture remain poorly understood.

AIM

To observe and summarize the spatially applied anatomical characteristics for intervertebral foramen puncture on different vertebral segments.

METHODS

A total of 88 patients (41 males and 47 females) who underwent thoracic minimally invasive interventional treatment at Nanjing Drum Tower Hospital from January 2019 to June 2020 were included. Computed tomography images of 167 thoracic vertebral segments scanned in the prone position were collected. The width of the intertransverse space (D_P), the height of the rib neck/head above the lower transverse process (D_R), the width of the lateral border of the articular process/lamina (W_P), and the width of the posterior border of the vertebral body (W_V) were measured. At the upper 1/3 of the intervertebral foramina, the horizontal inclination angle (α) from the lateral border of the articular process/lamina to the posterolateral border of the vertebral body was measured. The ratios D_R/D_P and W_P/W_V were calculated. The intervertebral foramen parameters were compared between segments.

RESULTS

No rib head/neck occlusion (D_R/D_P > 0) was found in the intertransverse spaces of T1-2 and T12-L1. The incidence of occlusion for the upper thoracic segments (T1-5, n = 138), middle thoracic segments (T5-9, n = 116), and lower thoracic segments (T9-L1, n = 80) were 76.81%, 100%, and 82.50%, respectively. The incidence of occlusion for the middle thoracic segments was significantly higher than that for the upper and lower thoracic segments (P < 0.05). The incidence of > 1/2 occlusion (D_R/D_P > 1/2) for the upper, middle, and lower thoracic segments was 7.97%, 74.14%, and 32.50%, respectively. The incidence of > 1/2 occlusion for the middle thoracic segments was significantly higher than that for the upper and lower thoracic segments (P < 0.05). W_P was longer than W_V on T1-2 to T9-10 and shorter than W_V on T10-11 to T12-L1. The horizontal puncture angle (α) into the external opening of the intervertebral foramina was positively correlated with the segments of the thoracic vertebrae from the cephalic to caudal portion (left: r = 0.772, P < 0.01; right: r = 0.771, P < 0.01), and the horizontal inclination angle for T11-12 and T12-L1 was 90°.

CONCLUSION

It is necessary to identify the spatial impact of the rib head/neck on the puncture path of the intervertebral foramina and design appropriate puncture angles for different segments.

Efficacy and safety of pulsed radiofrequency modulation of thoracic dorsal root ganglion or intercostal nerve on postherpetic neuralgia in aged patients: a retrospective study

BACKGROUND

Postherpetic neuralgia (PHN) is common in elderly patients and can be alleviated by pulsed radiofrequency (PRF). However, PRF treatments display different efficacy on different nerves. The purpose of this study was to evaluate the efficacy and safety of ultrasound-guided PRF modulation on thoracic dorsal root ganglion (DRG) or intercostal nerve (ICN) for PHN in aged patients and to provide a theoretical basis for clinical treatment.

METHODS

We classified aged patients into two groups, DRG group and ICN group, based on the needle tip position. Visual analogue scale (VAS) and concise health status questionnaire (Short-form 36 health/survey questionnaire, SF-36) were used to evaluate the pain intensity and the life quality of the patients before and 2, 4 and 12 weeks after the PRF treatments. We also recorded the adverse reactions during the treatments.

RESULTS

After the PRF treatment, the scores of VAS and SF-36 (assessing general health perception, social function, emotional role, mental health, and pain) improved significantly in both groups (P < 0.05). The mean VAS score in the DRG group was significantly lower than that in the ICN group 2 weeks after treatment, and remained for 12 weeks. The SF-36 scores in the DRG group were significantly higher than those in the ICN group (P < 0.05). We found a similar incidence of adverse reactions between the two groups (P > 0.05).

CONCLUSIONS

PRF therapy is safe and effective for elderly patients with postherpetic neuralgia. However, PRF treatment in dorsal root ganglion is superior to that in intercostal nerve with improving VAS and SF-36 scores to a greater extent in older patients.

TRIAL REGISTRATION

ChiCTR2100044176 .

Efficacy of Dorsal Root Ganglion Pulsed Radiofrequency Combined with Paravertebral Injection of Recombinant Human Interferon-α2b in Herpetic Neuralgia

Objective

The purpose of this study was to investigate the clinical efficacy of dorsal root ganglion (DRG) pulsed radiofrequency combined with paravertebral injection of recombinant human interferon-α2b in the treatment of patients with acute herpes zoster neuralgia and its preventive effectiveness on postherpetic neuralgia (PHN).

Methods

A retrospective analysis of 62 patients with acute herpes zoster neuralgia was implemented. All patients were divided into two groups: pulsed radiofrequency paraspinal injection of recombinant human interferon-α2b (group P); pulsed radiofrequency combined with paravertebral injection of saline (group C). The numerical rating scales (NRS) scores were used for pain assessment, and the dose of the analgesic drug was recorded. Gal-3 and IL-6 levels in blood were compared between the two groups before treatment and at 1 week, 2, and 4 weeks after treatment. The incidence of PHN was recorded in both groups.

Results

The pain intensity, the levels of Gal-3 and IL-6 in blood and the dose of oral administration of gabapentin capsules and morphine were reduced in all patients after treatment. Compared with group C, patients in group P had lower NRS scores, blood levels of Gal-3 and IL-6, and dosages of oral gabapentin capsules and morphine hydrochloride immediate-release tablets after treatment. The incidence of PHN was significantly lower at 8 and 12 weeks.

Conclusion

DRG pulsed radiofrequency combined with paravertebral injection of recombinant human interferon-α2b for acute stage herpes zoster neuralgia is a more effective treatment, and can effectively prevent the incidence rate of PHN.

Application of Nalbuphine in Trigeminal Ganglion Pulse Radiofrequency Surgery in Patients with Postherpetic Neuralgia

This study aimed to explore the application value of nalbuphine in pulsed radiofrequency operation of trigeminal ganglion in patients with postherpetic neuralgia (PHN). Thirty patients with PHN were randomly divided into the nalbuphine (Nalbu) group and ketorolac tromethamine (KT) group and received CT-guided pulsed radiofrequency surgery on trigeminal ganglion. The numeric rating scale (NRS) scores of patients were recorded at preoperative, intraoperative, and postoperative time points, before going to bed, and the next morning after the operation. In addition, the number of breakthrough pain before operation and within 24 hours after operation, the incidence of nausea and vomiting within 24 hours after surgery, and the patient's sleep quality before and on the day after surgery were evaluated. The outcome data demonstrated that patients treated with nalbuphine had lower NRS scores after the pulse radiofrequency operation during and after the pulse radiofrequency operation compared to those with KT. In addition, nalbuphine effectively decreased the number of breakthrough pain, reduced the occurrence of nausea and vomiting after surgery, and improved the sleep quality. In conclusion, intramuscular injection of nalbuphine 30 min before trigeminal ganglion pulse radiofrequency surgery can be conducive to pain relief and improve the postoperative comfort of patients, providing an effective alternative for the alleviation of PHN in clinic.

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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Application and Therapeutic Effect of Puncturing of the Costal Transverse Process for Pulsed Radiofrequency Treated T1-T3 Herpes Zoster Neuralgia

Purpose

In CT-guided dorsal root ganglion puncture, especially T1–T3, it is often difficult to reach the target due to obstruction of the lamina, transverse process, and ribs. Therefore, a safe and effective puncture method with high success rate is urgently needed to guide us in our clinical work.

Patients and Methods

A total of 44 patients with dorsal root ganglion underwent pulsed radiofrequency therapy for pain T1–T3 herpes zoster neuralgia at the pain department of Affiliated Hospital of Jiaxing University from January 2019 to February 2020 were retrospectively reviewed. Each patient underwent the same surgical method. The patient’s operation time, CT filming times, nerve electrophysiological tests, the NRS scores before and after operation at one, four, eight, and 12 weeks, Pittsburgh Sleep Disorder Index (PSQI), dosage of gabapentin capsules and tramadol hydrochloride sustained-release tablets, surgical complications and incidence of postherpetic neuralgia (PHN) were recorded.

Results

The success rate of 44 patients who underwent puncturing of the costal transverse process to T1 target was 88.46%, to T2 target was 90.68%, and to T3 target was 90.68%, respectively. The NRS score of patients before surgery was 5.48±0.59, and those at one, four, eight, and 12 weeks after surgery were 3 (3,3), 1 (1,2), 0 (0, 1), and 0 (0, 0). The difference of NRS score between preoperation and postoperation is statistically significant. No intraoperative and postoperative complications occurred. Two patients developed PHN after standard treatment, and the incidence of it was 4.55%.

Conclusion

CT-guided puncturing of the costal transverse process in the dorsal root ganglion of patients who underwent pulsed radiofrequency treatment of T1–T3 herpes zoster neuralgia showed a high success rate and is considered to be safe and effective.

Supraorbital Nerve Radiofrequency for Severe Neuralgia Caused by Herpes Zoster Ophthalmicus

Background

Radiofrequency of the Gasserian ganglion can be used for ophthalmic herpetic neuralgia (OHN), but it is associated with complications. This study aimed to use the supraorbital nerve for computed tomography- (CT-) guided radiofrequency thermocoagulation to treat refractory OHN.

Methods

This was a retrospective case series study of patients with simple or combined OHN treated at our hospital between 06/2012 and 06/2018. The numerical rating score (NRS), spontaneous pain, allodynia, gabapentin dosage, paracetamol/oxycodone dosage, patient global impression of change (PGIC) score, Barrow numbness score, postoperative 360-day recurrence rate, and complications were recorded before the operation and at 1, 30, 90, 180, and 360 days after the operation.

Results

Compared with baseline, the NRS was decreased, and PGIC was increased at postoperative 1, 30, 90, 180, and 360 days, and the gabapentin and paracetamol oxycodone doses at postoperative 30, 90, 180, and 360 days were decreased (all P < 0.001). Compared with 1 day after the operation, numbness was decreased at 30, 90, 180, and 360 days after the operation (P < 0.001). Compared with baseline, the number of patients with allodynia at each time point after the operation was decreased (P < 0.001), but without a difference for spontaneous pain (P=0.407). No subjects showed drooping eyelid, corneal ulcers, eyeball damage, decreased vision, and other severe complications.

Conclusion

CT-guided supraorbital nerve radiofrequency thermocoagulation for the treatment of OHN can effectively relieve pain and reduce the dose of analgesics, without any serious complication. This study suggests that this technique is feasible and applicable to clinical practice.

Pulsed radiofrequency of dorsal root ganglion of upper thoracic segment for herpes zoster neuralgia: Case report

RATIONALE

Pulsed radiofrequency (PRF) therapy of dorsal root ganglion is effective in treating acute stage shingles neuralgia of chest and back. Herein, a case of herpetic neuralgia with difficult puncture of dorsal root ganglion of upper thoracic segment is report.

PATIENT CONCERNS

A 62-year-old male patient was admitted to the hospital for 2 days for herpes zoster with paroxysmal needle-like pain in the left chest and back. The skin lesion area of herpes zoster and the superficial location of neuralgia was left T2-4, and visual analog scale (VAS) score was 6 points.

DIAGNOSIS

Two days ago, the patient had paroxysmal needle-like pain in the left chest and back, without herpes, and was admitted to the hospital for emergency treatment. Chest pain and myocardial infarction were considered; however, troponin, myocardial enzyme spectrum, and blood amylase were in the normal range. On the evening of the same day, the patient presented green bean-sized blisters distributed in clusters along the left T2-4 nerve as a banded pattern. Thus, the patient was diagnosed as shingles.

INTERVENTION

Oral gabapentin capsules, varaciclovir tablets, mecobalamine tablets, and amitriptyline hydrochloride tablets were administered, and topical aciclovir cream was applied. The VAS score after the above treatment was 5 points. The patient underwent computed tomography-guided PRF surgery on the dorsal root ganglion.

OUTCOME

Postoperative pain was relieved. One month post-surgery, no oral analgesic drugs were administered. The VAS score was 1 point, and the pain completely disappeared at 3 months post-surgery.

CONCLUSIONS

Herpes zoster is most common in the chest and back. The PRF of dorsal root ganglion cannot access the target by conventional puncture, and can be completed by thoracic sympathetic nerve radiofrequency puncture path.