The patient came to the clinic 20-December-2017 complaining of click of the right knee and the back for 2 years with right sciatica. 1 Year ago felt down and got left sciatica. 3 months later the left sciatica disappeared and got right sciatica. MRI lumbar spine performed 09-July-2017 showing extruded disc L4-5 with right foraminal occlusion. On examination at that time she was limping with exaggerated scoliotic stance. SLRS was 70 degrees with pain in the right, weak dorsiflexion right foot -4/5 and hypalgesia right L5 territory. The patient was sent for investigation. Showing extruded disc L4-5 with right foraminal occlusion. Dynamic studies showed GII spondylolisthesis. The patient was advised to undergo surgery, but she disappeared. The patient then came 09-July-2018 urging for surgery with dramatic deterioration last 20 days.

On examination, she was limping with scoliotic stance. SLRS was 60 degrees right side with pain. There was weak dorsiflexion right foot -4/5. There is hypalgesia right L5 territory.

Skeletonization L4 and L5 until the lateral proccessi are visible. Transpedicular fixation L4-5 using 4 OSImplant monoaxial screws 6.5x45  and 2 bended rods.  Monopolar stimulation of all L4 screws was not achieved even with 10 mA current. The right L5 screw gave response to 4.5 mA. The left gave response to 6 mA.  Foraminotomy right L5 root  with inspection of the disc surface which was decided not to violate it. Using MultiGen, bipolar motor stimulation of the right L5 root was achieved with 1.4 V. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to the right L5 root was achieved using 2 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the right L5 root was achieved with 1.3 V. The bended rods were inserted and distraction was applied and the harvested bone was applied lateral to the rods.  Routine closure of the wound.

Smooth postoperative recovery. The power of the right foot became normal. She was sciatica free. She was sent to the ward.

This is the 157th 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.

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.

Cross connector was not applied here because it was single level and to insert it it was necessary to removed further bones  and cause more destruction.