The Effect of Interventional Pain Management on Treating Postherpetic Neuralgia

Efficacy and Safety of High-Voltage Pulsed Radiofrequency versus Standard-Voltage Pulsed Radiofrequency for Patients with Neuropathic Pain: A Literature Review and Meta-Analysis

Background

Neuropathic pain (NP) is recognized as one of the most difficult pain syndromes which lacks a safe, well-tolerated and effective treatment. Pulsed radiofrequency (PRF), a novel and minimally invasive interventions, has been introduced to alleviate various types of NP. Previous studies reported PRF with higher voltage could further improve the treatment efficacy. Therefore, we conducted this systematic review and meta-analysis to determine whether high-voltage PRF is superior to standard-voltage PRF for the treatment of NP patients.

Methods

Databases published from the date of inception until 15 March 2022 on PubMed/MEDLINE, EMBASE, Web of Science and the Cochrane Library were searched for RCTs comparing high-voltage PRF and standard-voltage PRF in NP patients. The primary outcome measures were the efficiency rates of NP patients with high-voltage PRF or standard-voltage PRF treatment. Data analysis was conducted using the Review Manager software (RevMan V.5.3).

Results

Six RCTs involving 423 patients were included in our meta-analysis. Compared with standard-voltage PRF group, the high-voltage PRF group attained a higher efficiency rate at 1 month (P = 0.04; I2 = 0%), 3 months (P = 0.04; I2 = 0%), 6 months (P = 0.002; I2 = 0%) post-procedure respectively. There was no significant difference in the complications between the two groups.

Conclusion

Our study supported that high-voltage PRF attained more satisfactory efficacy than standard-voltage PRF without increased side effects. High-voltage PRF could be a promising, effective, minimally invasive technology for NP patients.

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.

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.

Pulsed Radiofrequency Combined With Methylene Blue Paravertebral Nerve Block Effectively Treats Thoracic Postherpetic Neuralgia

Objective

To compare the effect, safety, and patient satisfaction of pulsed radiofrequency combined with methylene blue paravertebral nerve block and pulsed radiofrequency alone in the treatment of thoracic postherpetic neuralgia (PHN).

Methods

A total of seventy-two patients with PHN diagnosed in the Department of Pain Management of Shengjing Hospital at China Medical University, from September 2019 to April 2021, were enrolled in the study. Patients were randomly divided into two groups. Group A (n = 36) received pulsed radiofrequency treatment. Group B (n = 36) received pulsed radiofrequency + methylene blue paravertebral nerve block. Patients were followed-up at 1 day, 1 week, 1 month, 3 months, and 6 months after treatment. Observation at each follow-up included basic patient characteristics, Visual Analog Scale (VAS), Hospital Anxiety and Depression Scale (HAD), the Insomnia Severity Index (ISI), patient satisfaction, complications, and side effects.

Results

Compared with preoperative values, the VAS scores significantly decreased in both groups at each postoperative time point (1 day, 1 week, and 1, 3, and 6 months; all p < 0.05). Compared with group A, VAS scores in group B were significantly lower 1 week and 1 month after surgery (p < 0.05). Patients in group B had lower HAD scores than those in group A 1 week after surgery (p < 0.05). Patients in group B had lower ISI scores than those in group A 1 day, 1 week, and 1, 3, and 6 months after surgery (p < 0.05). The pregabalin dosage in group B was lower than that in group A at 1 and 6 months after surgery (p < 0.05). Patient satisfaction was higher in group B than in group A at 1 week and 6 months after surgery (p < 0.05). There were no serious complications or side effects in either group.

Conclusion

Pulsed radiofrequency combined with methylene blue paravertebral nerve block is superior to pulsed radiofrequency alone in the treatment of thoracic PHN, which can significantly relieve PHN and improve the condition of sleep and emotional disorders. Therefore, it is a safe and effective treatment method.

Effective Treatment of Postherpetic Neuralgia at the First Branch of the Trigeminal Nerve by High-Voltage Pulsed Radiofrequency

Background: Postherpetic neuralgia (PHN) is one of the most common and serious complications of herpes zoster. PHN of the first branch of the trigeminal nerve is painful and difficult to treat, as no definitive effective treatment is available. The aim of this retrospective study was to observe the efficacy and safety of treatment of PHN of the first branch of the trigeminal nerve with high-voltage pulsed radiofrequency (PRF) of the supraorbital nerve.

Methods: Fifty-two patients diagnosed with the PHN of the first branch of the trigeminal nerve at the Department of Pain Management, Shengjing Hospital, China Medical University, between April 2017 and October 2020 were selected. The PRF treatment of the supraorbital nerve was used. The patients were divided into two groups according to the treatment received: group C, conventional PRF group; and group H, high-voltage PRF group. The basic conditions, pain scores, and SF-36 scores of patients before treatment were recorded. Also, intraoperative and postoperative adverse events, visual analog scale (VAS) scores, 36-Item Short Form Health Survey (SF-36) scores at 1 week, 1 month, 3 months, and 6 months of follow-up were recorded. Furthermore, treatment efficiency was followed up at 6 months after treatment.

Results: The VAS scores of patients in both groups were significantly lower at all time points after treatment compared with presurgery. VAS scores in group H were lower than those in group C 1, 3, and 6 months after treatment. SF36 scores of patients in group H were better than those in group C 1, 3, and 6 months after treatment. The treatment efficiency at 6 months after treatment was higher in group H than in group C. No serious adverse events occurred in both groups.

Conclusion: The efficacy of the high-voltage PRF of the supraorbital nerve in treating the PHN of the first branch of the trigeminal nerve was superior to that of conventional PRF. It was a safe and effective treatment method.

Efficacy of different interventions for the treatment of postherpetic neuralgia: a Bayesian network meta-analysis

Objective

We aimed to perform a network meta-analysis that combined both direct and indirect evidence to compare the relative efficacy of interventional therapies to treat patients with postherpetic neuralgia (PHN) and to determine the treatments’ superiority and validity.

Method

A conventional paired meta-analysis was performed. This was followed by a network meta-analysis using the Bayesian framework.

Results

Botulinum toxin type A and pulsed radiofrequency (PRF) were the two most effective individual interventions. For combination therapy, PRF + nerve block (NB) was the best choice, followed by subcutaneous injection or local infiltration (SC) + NB + ozone (O3). However, the combination of PRF + NB + SC showed reduced the efficacy compared with each treatment and was highly invasive for patients. After a long-term follow-up, PRF was shown to be the most effective therapy for treating patients with PHN.

Conclusions

Regular anti-neuropathic drug administration that was accompanied by interventional therapies at an early stage is the best choice to treat patients with PHN. Appropriate combinations of different interventions show improved pain relief. Clinicians should manage therapeutic regimens on the basis of the patients specific condition and existing measures and strive to achieve personalized treatment.

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.

CT-Guided Pulsed Radiofrequency at Different Voltages in the Treatment of Postherpetic Neuralgia

Background

Postherpetic neuralgia (PHN) is a form of long-lasting neuropathic pain that can severely affect patients’ quality of life. Pulsed radiofrequency (PRF) has been proven to be effective in treating PHN, but the optimal radiofrequency parameters are still not well defined. This retrospective study aimed to compare the efficacy and safety of CT-guided PRF at three different voltages for the treatment of PHN patients.

Methods

This study included 109 patients with PHN involving the thoracic dermatome who were treated in the Department of Pain Management of Shengjing Hospital, China Medical University, from January 2017 to May 2019. They were divided into three groups based on the PRF voltage used: group A (45 V), group B (55 V), and group C (65 V). The PRF therapy (voltage 45, 55, and 65 V) was performed in all patients by targeting the thoracic dorsal root ganglion. After surgery, patients were followed at 3 days, 1 month, 3 months, 6 months, and 12 months. Observation at each follow-up included basic patient characteristics, visual analog scale (VAS), 36-Item Short Form Health Survey (SF-36) scores, patient satisfaction, complications, and side effects.

Results

Visual analog scale scores decreased and SF-36 scores increased for all patients in the three groups at each post-operative time point (1, 3, 6, and 12 months; all P < 0.01). Pain relief, improvement in quality of life, and overall satisfaction were more significant for patients in group C than for those in groups A and B at the 3-, 6-, and 12-month follow-ups (all P < 0.05). Patients in group B had lower VAS scores and higher overall satisfaction levels than those in group A (both P < 0.01). A small number of patients from each group (n ≤ 3) experienced mild intraoperative and post-operative complications, which bore no relationship with group assignment (all P > 0.05). At post-operative day 3, patients in group C had skin numbness affecting a larger area than patients in the other two groups (both P < 0.05), but the differences were no longer statistically significant at day 30 after the operation. All patients experienced a drop in numbness area of more than 30% after surgery.

Conclusion

Compared with PFR at 45 and 55 V, PFR at 65 V had superior efficacy in treating PNH, with a favorable safety profile.