Combined therapy of pulsed radiofrequency and nerve block in postherpetic neuralgia patients: a randomized clinical trial.

Jianping Yang,Guohua Sun,Yanjuan Wang,Hanzhe Sun,Zhiping Wang,Dan Li

doi:10.7717/peerj.4852

Jianping Yang, Guohua Sun + Show 4 more

Open Access

https://doi.org/10.7717/peerj.4852

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Abstract

Caused by viral infection, postherpetic neuralgia (PHN) is the most common chronic neuropathic pain. Various treatment modalities such as early use of nerve block therapy (NBT) and pulsed radiofrequency (PRF) have been studied in reducing pain, however, no consistent success was achieved in all the patients treated with single regimen. The combined therapy of PRF and NBT with different targeting mechanism are of interest and remains to be determined. Here we investigated the combined effects of pulsed radiofrequency (PRF) with nerve block therapy (NBT) in PHN patients in a prospective randomized clinical trial. Sixty PHN patients were divided into four groups (n = 15 each): the conventional puncture group (group CP), the nerve block therapy group (group NB), the PRF group (group PRF), and the combined treatment group (PRF combined with nerve block therapy (group CT). To evaluate the extent of remission of hyperalgesia, we recorded the visual analogue scale (VAS) scores during cotton swab reaction before and after treatment and in the resting and active pain states. In addition, blood samples were collected and plasma cytokine and neuropeptides such as interleukin-6 (IL-6), substance P (SP), and β-endorphin (β-EP) were measured by enzyme-linked immunosorbent assay (ELISA) at the admission (basic state), before the operation, and at 12 h postoperatively. The number of adverse events (nausea, vomiting, constipation, puncture point hemorrhage, swelling and redness) within 12 h of the treatment were also documented. Our results showed that VAS scores during cotton swab reaction decreased after treatment in all patients (p < 0.05). Compared to group CP, plasma IL-6 and SP levels decreased (p < 0.05) and β-EP levels increased (p < 0.05) in groups NB, PRF, and CT. There were no significant differences in adverse events among groups (p > 0.05). We found that PRF in combination with NBT increased β-EP levels and decreased plasma IL-6 and SP, thereby alleviating pain and hyperalgesia in PHN patients. Taken together, our data suggest combined therapy of PRF and NBT is effective and safe for PHN patients.

Highlights

Postherpetic neuralgia (PHN) is the most common chronic nerve pain caused by chickenpox viral infection
Sixty PHN patients were divided into four groups according to a computer-generated random number table (n = 15 in each group): the conventional puncture group, the nerve block therapy group, the pulsed radiofrequency (PRF) group, and the combined treatment group (PRF combined with NB therapy, group CT)
Group RN, combined treatment group

Summary

INTRODUCTION

Postherpetic neuralgia (PHN) is the most common chronic nerve pain caused by chickenpox (herpes zoster) viral infection. Recent studies showed that traditional oral drugs, nerve block therapy (NBT) and pulsed radiofrequency (PRF) can shorten pain duration in some patients (Johnson & Rice, 2014; Kim et al, 2017; Shi & Wu, 2016). Combinational treatments are needed in many PHN cases and in chronic cervical radicular pain (McCrary, Severson & Tyring, 1999; Wang et al, 2017; Xiao et al, 2015). The current trail aimed to systematically evaluate the efficacy and safety of a combined therapy of PRF and NBT compared to traditional single-modality treatment such as oral drugs, nerve blocker administration, and PRF for PHN patients by recording VAS score in cotton-swab test. We explored the underlying analgesic mechanisms by measuring the plasma IL-6, SP, and β-EP

Study design and participants

RESULTS

DISCUSSION