Preliminary Results of Pulsed Radiofrequency Thermocoagulation for Lumbar Radiculopathy: Short Term Follow-up

Shim, Jae Chol; Cho, Hee Young; Kim, Dong Won; Seung, Ik Sang

Abstract

BACKGROUND: Application of pulsed radiofrequency (RF) current to the dorsal root ganglion has been reported to produce short term relief of spinal pain without causing thermal ablation in failed back surgery patients. The present study was undertaken to investigate the influence of pulsed RF thermocoagulation of dorsal root ganglion for chronic segmental pain radiating to the legs.
METHODS
It was an open, prospective, pilot study of the effect of pulsed RF adjacent to the dorsal root ganglion in patients with radiating lower extremity pain. Following diagnostic segmental block, a maximum of 2 dorsal root ganglia were treated. Out of 23 patients, 6 were lost to follow up, and pulsed RF was applied to the remaining 17. The short term clinical effect of pulsed RF treatment (20 msec RF pulse delivered at a rate of 2 Hz for 240 sec to produce tissue heated to 42degrees C) was investigated.
RESULTS
Satisfactory results were defined as 50% reduction of original pain. Five cases were successful out of 19 cases at a mean follow up period of 44.8 +/- 18.6 days. Transient motor weakness was observed (duration 7 days) in one case. We also found transient pain relief in patients whose pain relief was not successful (duration; 3-35 days).
CONCLUSIONS
Treatment with pulsed, but not continuous, RF was associated with improvement of radiating pain in patients with or without spinal surgery. The electromagnetic field may be instrumental in producing the clinical effect of the RF lesion adjacent to the dorsal root ganglion. If a meticulous technique of pulsed RF and patient selection criteria for pulsed RF were prepared, pulsed RF would be a useful treatment modality for pain clinicians who are treating radiating pain of lower extremities.