Background: Postherpetic neuralgia (PHN) is pain persisting beyond 3 months from rash onset and is the most common complication of herpes zoster (HZ); it is commonly refractory to medication treatment. Available evidence indicates that high-voltage, long-duration pulsed radiofrequency (PRF) to the dorsal root ganglion (DRG) is a novel and effective treatment for this complication. Nevertheless, the effects of this intervention on refractory HZ neuralgia less than 3 months have not been evaluated.
Objective: The objective of this study was to assess the therapeutic efficacy and safety of high-voltage, long-duration PRF to the DRG for patients with subacute HZ neuralgia compared with that of patients with PHN.
Study design: A retrospective comparative research.
Setting: Hospital department in China.
Methods: Sixty-four patients with HZ neuralgia in different stages receiving high-voltage, long-duration PRF to the DRG were included. According to the days from zoster onset to PRF implementation, they were divided into the subacute (one to 3 months) or PHN group (more than 3 months). The therapeutic effect was evaluated by pain relief using the Numeric Rating Scale at one day, one week, one month, 3 months, and 6 months post-PRF. The five-point Likert scale measured patient satisfaction. Post-PRF side effects were also recorded to determine the safety of the intervention.
Results: The intervention significantly reduced pain in all patients, but pain relief at one month, 3 months, and 6 months post-PRF was better in the subacute group than in the PHN group. Furthermore, the success rate of PRF was significantly increased in the subacute group compared with the PHN group (81.3% vs 56.3%, P = 0.031). There was no significant difference in patient satisfaction at 6 months between groups.
Limitations: This is a single-center retrospective study with a small sample size.
Conclusions: High-voltage, long-duration PRF to the DRG is effective and safe for HZ neuralgia in different stages, and can provide an improved pain relief for HZ neuralgia in the subacute stage.
Keywords: dorsal root ganglion; postherpetic neuralgia; subacute herpes zoster neuralgia; Pulsed radiofrequency.