Comparison of two distinct needle tip positions in pulsed radiofrequency for herpes zoster-related pain

Abstract

Background: Herpes zoster (HZ)-related pain, characterized by chronic and persistent pain with a dermatomal distribution, is a relatively common complication of HZ. Pulsed radiofrequency (PRF) can effectively relieve HZ-related pain. There is no study on the effect of the needle tip position in patients with HZ for PRF treatment. This prospective study was conducted to compare two distinct needle tip positions in PRF for HZ-related pain.

Methods: Seventy-one patients suffering from HZ-related pain were enrolled in this study. According to the dorsal root ganglion (DRG) position and needle tip position, patients were randomly allocated to the IP group (group inside of the pedicle, n = 36) and OP group (group outside of the pedicle, n = 35). Quality of life and pain control were evaluated with the visual analog scale (VAS) and activities of daily living questionnaires (including 7 items: general activity, mood, walking ability, normal work, relations with other people, sleep, and enjoyment of life), which were administered before therapy and at intervals of 1, 7, 30, and 90 days after therapy.

Results: Before therapy, the mean pain score was found to be 6.03 ± 0.45 in the IP group and 6.00 ± 0.65 in the OP group (p = 0.555). No significant differences were found when the two groups were compared at 1 and 7 days after therapy (p > 0.05). But, the pain score was significantly lower in the IP group at 30 days (1.78 ± 1.31 vs. 2.77 ± 1.31, p = 0.006) and 90 days of follow-up (1.29 ± 1.19 vs. 2.15 ± 1.74, p = 0.041). Significant differences between the two groups in terms of general activity (2.39 ± 0.87 vs. 2.86 ± 0.77, p = 0.035), mood (1.97 ± 1.65 vs. 2.86 ± 1.50, p = 0.021), relations with other people (1.94 ± 0.92 vs. 2.51 ± 1.22, p = 0.037), sleep (1.64 ± 1.44 vs. 2.97 ± 1.44, p < 0.001), and enjoyment of life (1.58 ± 1.11 vs. 2.43 ± 1.33, p = 0.004) were detected after the 30-day follow-up. In addition, scores for the activities of daily living were significantly lower in the IP group than that in the OP group at 90 days after therapy (p < 0.05).

Conclusion: The needle tip position had an influence on the PRF treatment in patients with HZ-related pain. Positioning the needle tip in the area between the medial and lateral edges of adjacent pedicles offered good pain relief and improved quality of life in HZ patients.

Keywords: DRG position; herpes zoster; needle tip position; pulsed radiofrequency.