High-voltage pulsed radiofrequency combined with tolerable thermocoagulation for the treatment of postherpetic neuralgia: study protocol for a randomized controlled trial

Abstract

Postherpetic neuralgia (PHN) is a common and debilitating complication of herpes zoster that significantly affects patients’ quality of life, particularly among elderly and immunocompromised individuals. Although pharmacological therapies are widely used, they often provide limited pain relief and have undesirable side effects. Minimally invasive interventions, such as pulsed radiofrequency (PRF), have shown promise in pain management. However, the optimal approach to combining high-voltage PRF (HV-PRF) with tolerable thermocoagulation remains under-investigated. This study aims to evaluate the efficacy and safety of HV-PRF combined with tolerable thermocoagulation compared to HV-PRF alone in the treatment of PHN. This single-center, prospective, randomized, single-blind, controlled trial will enroll 60 eligible patients with thoracic PHN. Participants will be randomized in a 1:1 ratio to receive either HV-PRF combined with tolerable thermocoagulation (experimental group) or HV-PRF alone (control group). The primary outcome is the Visual Analog Scale (VAS) pain score at 1 day post-treatment, which was prespecified to assess the early incremental analgesic effect of adding tolerable thermocoagulation under standardized peri-interventional conditions. Secondary outcomes include VAS pain scores at 7 days, 1 month, and 3 months post-treatment to assess the durability of analgesia; sleep quality assessed by the Athens Insomnia Scale (AIS); anxiety evaluated by the Hamilton Anxiety Scale (HAMA); depression measured by the Patient Health Questionnaire-9 (PHQ-9); length of hospital stay; and the use of rescue analgesics. Sample size was calculated using PASS software, and data will be analyzed using SPSS version 23.0 and GraphPad Prism version 8.0. Statistical tests will include t-tests, Mann–Whitney U tests, chi-square tests, Fisher’s exact test, Kaplan–Meier analysis, and linear mixed-effects models. This study will provide valuable insights into the efficacy and safety of combining high-voltage pulsed radiofrequency with tolerable thermocoagulation for postherpetic neuralgia. Results from this study are expected to inform clinical practice by identifying a potentially more effective and patient-friendly treatment approach for this challenging condition. The trial was registered prospectively at the Chinese Clinical Trial Registry (ChiCTR) under registration number ChiCTR2500095846 on 14 January 2025. The full trial record is available at www.chictr.org.cn .