The patient was operated elsewhere 2 years ago for extruded lumbar disc unknown level. The patient came to the clinic 02-January-2019 complaining of LBP with right sciatica for 10 days with agonizing right sciatica. MRI lumbar spine performed 24-December-2018 showing extruded disc L5-S1 with severe right S1 root compression. The patient telling that 5 days ago, he got difficult micturition, for what Foley's catheter was inserted temporarily.

On examination: He is walking with help with agonizing sciatica. SLRS was 5 degrees right side with severe pain and 75 degrees in the left without pain. There was weak dorsiflexion right foot 3/5, analgesia right L5 and hypalgesia right S1 root with absent right AJ. There is a 6 cm length incision at L4-5-S1 level.

Foraminotomy right S1 root with removal of the extrusion lateral to the axilla and right sided cleaning L5-S1 disc space. Using MultiGen, bipolar motor stimulation of the right S1 root was achieved with 6.0 Volts?. Repetition of the procedure with other cables showed the same results. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to right S1 root was achieved using 2 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the right S1 root was achieved with 2.0 V with more brisk response as before. The patient was put in Reverse Trendelenburg position with Valsalva maneuver. No CSF leak. Routine closure of the wound.

Smooth postoperative recovery. The power of the right foot improved and the sciatica disappeared. He was sent to the ward.

There is still an estimated postoperative re-recurrence around 7%, because the disc space height is still not shallow.

This is the 172d case using the BPRF mode with MultiGen. This procedure regained routine acceptance.  It became a usual part of the spine and peripheral nerves surgery. Click here for reference.

It still unclear to evaluate the differences of pre and post application motor responses. The only sure thing that it tells that the electrodes did not migrate during the procedure and the nerve is functioning properly. Here the threshold of stimulation power of motor stimulation of the affected root after application improved dramatically, but the motor stimulation was very high before the application, denoting the severe damage of the root and acceptable recovery of the root after BPRF.

With accumulation of data, it became clear that the irritated nerve with aberrant currents running in the C fibers up, not only causing no change or elevation of the required voltage to achieve motor response, but they could cause the preoperative weakness. Ablation of such currents results in facilitation of the motor response and improvement of function with disappearance of pain.

It is unclear why the roots have several motor response with different patients, despite the fact that the neurological status is the same and the anesthesia protocol also the same.

It could be that the nerve is recovering minute by minute after decompression and this can explain why the motor conductivity is improving after the BPRF application, which require 4 minute session in most cases.

This is the first case, that the root was responding only to 6Volts and higher before the BPRF.