The Effect of Pulsed Radiofrequency Field Applied to Dorsal Root Ganglion

Background: With the use of L2 spinal nerve block, an improvement in the symptoms of patients with discogenic lower back pain has been reported. The clinical effect of pulsed radiofrequency thermocoagulation (pulsed RFTC) of the L2 dorsal root ganglion, in patients with failed back surgery syndrome (FBSS) or lower back pain without radiating leg pain, has been found. This investigation was an open prospective study of the effect of pulsed RFfC in patients with lower back pain. Methods: The long term outcomes were ascertained in 16 patients that underwent pulsed RFTC of the L2 dorsal root ganglion, who had shown an improvement in their symptoms following L2 diagnostic blockade. Under the guidance of a C-arm image, a nerve block needle was placed at the L2 dorsal root ganglion. During the pulsed RFTC, the sensory and motor ENS (electrical nerve stimulation) was assessed. Five of the 16 patients were treated unilaterally. There were 2 patients with a history of a laminectomy and 2 others with a spinal fusion. Twelve of the 16 patients were available for follow up. The demographic picture of the enrolled patients was in range of age 51 9 (mean SD) years. For the assessment of lower back pain, the 4 point Likert scale was adopted. Results: Of the 12 patients followed up, 7 showed symptom improvements of over 50%, and 4 showed no improvements. The other patient showed only a moderate degree of improvement in the symptoms. The average follow-up interval was 185 (184.8 57.0) days. There was one patient with a previous history of lamineclorny. Seven patients reported a reduction of their pain of more than 50%. The sensory ENS threshold values ranged from 0.24 to 1.9 volt, and the motor ENS threshold from 0.34 to 1.54 volt. Conclusions: Pulsed RFTC of the L2 dorsal root ganglion would be effective in patients with lower back pain, with no improvement in the symptoms following conservative treatment. Further research, with a randomized controlled prospective study design, is needed to determine the effectiveness of pulsed RF on the L2 dorsal root ganglion.