1. 2019;22;E171-E179The Effectiveness and Safety of 42°C Pulsed Radiofrequency Combined with 60°C Continuous Radiofrequency for Refractory Infraorbital Neuralgia: A Prospective Study
   Observational Study
   Yitong Jia, MD, Zheng Chen, MD, Hao Ren, MD, and Fang Luo, MD.

BACKGROUND: Infraorbital neuralgia, one of the rare causes of facial pain, lacks systematic treatment guidelines because few studies on the topic have been published. We previously found that 42°C percutaneous nondestructive pulsed radiofrequency (PRF) treatment could achieve satisfactory pain relief for infraorbital neuralgia patients. However, patients who responded poorly to PRF had no other ideal treatment options until now. Recently, standard PRF combined with 60°C continuous radiofrequency (CRF) was successfully performed on trigeminal neuralgia patients and achieved a promising effective rate with mild complications. However, the efficacy of the combined therapy in the treatment of infraorbital neuralgia has not yet been reported.

OBJECTIVES: To evaluate the effectiveness and safety of 42°C PRF combined with 60°C CRF in infraorbital neuralgia patients who responded poorly to 42°C PRF and were reluctant to receive destructive therapies or nerve decompression surgery.

STUDY DESIGN: Prospective, single-center, observational clinical trial.

SETTING: The interventional pain management center in Beijing Tiantan Hospital.

METHODS: We prospectively investigated the effects of 10 minutes of 3-dimensional computer tomography-guided 42°C PRF combined with 270 seconds of 60°C CRF in the treatment of 28 patients with refractory infraorbital neuralgia. The response criterion was a postoperative verbal pain numeric rating scale score reduction of > 50%. The response rates at different time points during a 2-year follow-up were calculated.

RESULTS: The effective rates of combined PRF and CRF treatment were 95.5%, 86.4%, 81.8%, 72.7%, 72.7%, and 72.7% postoperative at 1 month, 3 months, 6 months, 1 year, 18 months, and 2 years, respectively. Except for 16 patients (72.7%) experiencing mild numbness that gradually disappeared within 1 week to 2 months after the operation, no obvious complications were observed.

LIMITATIONS: This study examined the therapeutic effectiveness over a period of only 2 years; no further follow-up was conducted. In addition, this study is a single-center observational clinical study with small sample sizes.

CONCLUSIONS: For patients with intractable infraorbital neuralgia, 42°C PRF combined with 60°C CRF is an effective and safe treatment. Prospective, double-blind randomized controlled trials with longer follow-up periods are needed to evaluate whether the combined treatment could become an alternative option for those who do not respond to conservative treatment, sparing those patients from destructive therapies or more invasive nerve decompression surgery.

KEY WORDS: Infraorbital neuralgia, effectiveness, safety, pulsed radiofrequency, continuous radiofrequency, combined therapy