Background: The mechanism of pain control with pulsed radiofrequency (PRF) is unclear.
Objectives: We aimed to compare the efficacy of combined PRF on dorsal root ganglion (DRG) with transforaminal epidural steroid injection (TFESI) vs TFESI-alone on pain improvement and serum tumor necrosis factor-alpha (TNF-a) level in lumbar disc-related radicular pain.
Study design: Prospective, randomized, controlled trial.
Setting: Neurology and Pain Management clinics.
Methods: A total of 80 patients with lumbar disc prolapse were divided into 2 groups: combined PRF on DRG with TFESI group and TFESI-alone group. The Numeric Rating Scale (NRS-11), Oswestry Disability Index (ODI), and Functional Rating Index (FRI) before intervention and at 2 weeks, 1 month, and 3 months after the intervention were observed. Serum TNF-a level was assessed pre- and post-intervention at 3 months.
Results: The scores of NRS-11, ODI, and FRI showed a significant improvement at 2 weeks, 1 month, and 3 months following intervention in both combined PRF & TFESI group and TFESI-alone group (P < 0.001 in all comparisons), with no significant difference between the 2 groups. Serum TNF-a levels showed a statistically significant reduction, 3 months following intervention in the combined PRF & TFESI group (P < 0.001), but not in the TFESI-alone group (P = 0.297) (P between groups < 0.001).
Limitations: The main limitation of this study is that TNF-a level was not assessed earlier to see how long the steroids might reduce TNF-a. On the other hand, further study with extended follow-up periods is needed to confirm the long-term lowering effect of TNF-a provided by PRF.
Conclusions: Combined PRF on DRG with TFESI showed similar outcomes to TFESI-alone in relieving pain in patients with lumbar disc prolapse. However, PRF on DRG caused a significant decrease in TNF-a serum levels at 3 months.
Keywords: lumbar disc prolapse; transforaminal steroids injection; tumor necrotic factor-alpha; Pulsed radiofrequency.