Electrocatheter-mediated High-voltage Pulsed Radiofrequency of the Dorsal Root Ganglion in the Treatment of Chronic Lumbosacral Neuropathic Pain: A Randomized Controlled Study

Abstract

Objectives: Despite the interest in scientific community, there is still poor evidence about pulsed radiofrequency (PRF) efficacy in the treatment of neuropathic pain. In order to determine whether high-voltage PRF and epidural adhesiolysis (PRF-EA) showed better results than epidural adhesiolysis alone (EA), a randomized, double-blind, comparative-effectiveness study was conducted in patients with chronic lumbosacral radiating pain and neuropathic features.

Materials and methods: A total of 41 patients were randomly allocated to 2 groups. Twenty-one patients were randomized to receive 2 cycles of 240 seconds high-voltage PRF followed by the injection of local anesthetics, hyaluronidase, and betamethasone, whereas 20 patients underwent sham stimulation followed by adhesiolysis. The treatment was delivered at the affected lumbosacral roots and patients, treating physicians and assessors were blinded to intervention.

Results: A significant reduction of radiating pain was observed in mean Numeric Rating Scale score at follow-up. A change of -3.43 versus -1.75 (P=0.031) after 1 month and -3.34 versus -0.80 (P=0.005) after 6 months was reported in patients undergoing PRF-EA in comparison with EA, respectively. After 1 month, 57% of patients in the PRF-EA group experienced a pain reduction of ≥50% versus only 25% of patients allocated to EA (P=0.037). Improvement decreased to 48% in the PRF-EA group whereas only 10% of EA reported significant pain relief after 6 months (P=0.008).

Discussion: High-voltage PRF of dorsal root ganglion delivered through multifunctional electrode provided significant pain relief and may be considered a valuable treatment in chronic lumbosacral radicular pain with neuropathic features.

FIGURE 1

Imaging of multifunctional electrode positioning close to dorsal root ganglion in pulsed radiofrequency (A) and epidural adhesiolysis (B).

FIGURE 2

Consort flow chart.

FIGURE 3

Comparison of mean NRS scores between the 2 groups at baseline, 1, and 6 months. *Statistical significance (P=0.031 and 0.005, respectively). EA indicates epidural adhesiolysis alone; NRS, Numeric Rating Scale; PRF-EA, pulsed radiofrequency and epidural adhesiolysis.

FIGURE 4

Comparison of mean Total Pain Rating Index rank (PRIr-T) scores between the 2 groups at baseline, 1, and 6 months. No statistical significance observed. EA indicates epidural adhesiolysis alone; PRF-EA, pulsed radiofrequency and epidural adhesiolysis; PRIr-T, Total Pain Rating Index rank.

FIGURE 5

Comparison of mean Oswestry Disability Index (ODI) scores between the two groups at baseline, 1, and 6 months. *Statistical significance (reached at 6 months only, P=0.024). EA indicates epidural adhesiolysis alone; PRF-EA, pulsed radiofrequency and epidural adhesiolysis.

FIGURE 6

Comparison of mean Douleur Neuropathique en 4 Questions scores between the 2 groups at baseline, 1, and 6 months. *Statistical significance (P=0.030 and 0.001, respectively). DN4 indicates Douleur Neuropathique en 4; EA, epidural adhesiolysis alone; PRF-EA, pulsed radiofrequency and epidural adhesiolysis.

FIGURE 7

Correlation between Douleur Neuropathique en 4 Questions and Numeric Rating Scale scores in patients undergoing pulsed radiofrequency after 1 and 6 months. (P=0.010). DN4 indicates Douleur Neuropathique en 4.