Comparing the efficacy and safety of short-term spinal cord stimulation and pulsed radiofrequency for zoster-related pain: A systematic review and meta-analysis

Efficacy and Safety of Pulsed Radiofrequency in Herpes Zoster Related Trigeminal Neuralgia: A Systematic Review and Meta-Analysis

Purpose

Pulsed radiofrequency (PRF) is a neuromodulation technique for neuropathic pain. However, the effects of PRF on zoster-related trigeminal neuralgia (TN) remain unclear. The purpose of this meta-analysis is to investigate the efficacy and safety of PRF in the management of zoster-related TN.

Patients and Methods

We searched PubMed, Embase, Cochrane Library, Chinese Biomedical Database (CBM), Chinese National Knowledge Infrastructure (CNKI), and Wanfang for randomized controlled trials from their inception to August 2022. The primary clinical outcomes included pain intensity and adverse events. Secondary clinical outcomes included pain remission rate, trigeminal postherpetic neuralgia (TPHN) incidence, rescue analgesic dose, sleep quality, and quality of life (QoL).

Results

Eight studies with 788 participants were included for final analysis. PRF group exhibited lower pain scores (week 1: MD -2.10, 95% CI -3.28 to -0.93, P=0.0005; week 4: MD -1.56, 95% CI -2.60 to -0.51, P=0.003; week 12: MD -1.52, 95% CI -2.68 to -0.35, P=0.01), lower risk of TPHN incidence (RR 0.22, 95% CI 0.06 to 0.81, P=0.02) and better sleep quality (week 4: MD -2.52, 95% CI -3.28 to -1.77, P<0.01; week 12: MD -2.25, 95% CI -2.90 to -1.60, P<0.01) than control group. Besides, pain remission rate (RR 1.08, 95% CI 0.93 to 1.26, P=0.31) and adverse events (RR 0.95, 95% CI 0.71 to 1.27, P=0.74) were comparable in both groups.

Conclusion

PRF is an effective and safe treatment and it yields better effects in pain relief, improvement of sleep quality, and prevention of developing TPHN. Although PRF provides a comparable pain remission rate with the control, it is still a preferred and alternative treatment for relieving zoster-related facial pain.

Comparison of a One- versus Two-Week Treatment with Famciclovir Upon Reductions in Pain and Occurrence of Postherpetic Neuralgia in Herpes Zoster: A Randomized Open-Label Trial

Background

Herpes zoster (HZ) is an acute herpetic skin disease resulting from the varicella-zoster virus. Typically, this condition is treated with a one-week administration of antiviral drugs, including famciclovir, which can effectively control the symptoms during the acute phase and prevent the occurrence of postherpetic neuralgia (PHN).

Objective

To investigate whether a longer, two-week, regimen would enhance the capacity for famciclovir to reduce pain and prevent the occurrence of postherpetic neuralgia.

Methods

HZ patients were randomly divided into two groups who were treated with famciclovir for either a one- or two-week period. Following their respective famciclovir treatments, patients were assessed for potential differences in pain intensity as evaluated at 1, 2, 4, 8 and 12 weeks post-treatment. In addition, the occurrence of postherpetic neuralgia at three months after treatment was compared between the two groups.

Results

Of the 86 patients initially enrolled, 80 completed the study with N=40 randomly assigned to each of the two groups. Pain scores decreased significantly at 1, 2, 4, 8 and 12 weeks after famciclovir treatments. There were no significant differences in pain scores, and the incidence of postherpetic neuralgia occurrence between the two groups. There were no statistically significant differences in reducing pain intensity or frequency of postherpetic neuralgia between the one-week and two-week treatment protocols.

Conclusion

It suggests that longer administration of famciclovir has no further benefit in the treatment of herpes zoster in our study.

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.