Pulsed radiofrequency of the dorsal root ganglion for chronic lumbosacral radicular syndrome refractory to epidural steroid injections

Abstract

Introduction: Approximately 20 % of patients with chronic lumbosacral radicular syndrome do not respond to epidural steroid injections. Pulsed radiofrequency of the dorsal root ganglion (DRG) is proposed as an alternative treatment. Objetive: To evaluate the analgesic effect of pulsed radiofrequency of the DRG in patients with chronic lumbosacral radicular syndrome, refractory to epidural steroid injections. Patients and method: 31 patients with chronic lumbosacral radicular syndrome that failed to at least two epidural steroid injections, received pulsed radiofrequency of the DRG, utilizing two cycles of 120 seconds, 45 V and 42 °C. Evaluation was carried out a month later. Brief Pain Inventory was applied before procedure and one month later. A reduction of 2 points in the verbal numerical scale (VNS) assessed with the question 6 of the Brief Pain Inventory, was considered a satisfactory analgesic response. Intensity and Interference Scores were calculated. Results: The VNS score decreased from 7.7 ± 2,2 to 5.9 ± 3 (p < 0.01). Intensity and Interference Scores were reduced from 7.1 ± 1.5 to 5.9 ± 2.1 (p < 0.01) and 7.1 ± 1.9 to 6.0 ± 2.3 (p < 0.02) respectively. In 12 patients (40 %) a satisfactory analgesic response was observed. In these patients the VNS decreased from 8.0 ± 1.5 to 3.8 ± 2.6. Intensity and Interference Scores were reduced from 7.4 ± 1.3 to 3.9 ± 1.5 (p < 0.0001) y 7.7 ± 1.9 to 4.9 ± 2,7 (p = 0.002) respectively. Conclusions: DRG pulsed radiofrequency produce a mild but statistically signifi cant reduction in VNS and pain interference, in patients with chronic lumbosacral radicular syndrome. However, in 40 % of the patients a satisfactory analgesic effect was observed. In some of them this changes persist after 3 months of the procedures.