The patient came to the clinic 28-December-2019 with severe LBP and agonizing left sciatica, pain and numbness left S1 territory for 2 months. MRI lumbar spine performed 23-December-2019 showing huge extruded disc L5-S1 with left foraminal occlusion.

On examination: The patient is in agonizing pain, limping with exaggerated scoliotic stance and has weak dorsi and planterflexion left foot -4/5. SLRS was 45 degrees with pain in the left.

Foraminotomy left S1 root with reflection of the ligamentum flavum to the right. The extruded disc was removed and left sided intradiscal cleaning L5-S1 was achieved. Using MultiGen, bipolar motor stimulation of the left S1 root was achieved with 1.8 Volts. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to left S1 root  was achieved using 2 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the left L5 root was achieved with 1.0 Volt. The patient was put in Reverse Trendelenburg position with Valsalva maneuver and hyperventilation. No CSF leak. The ligamentum flavum reflected back in place. Routine closure of the wound.

Smooth postoperative recovery. The power of left foot normalized. She is sciatica free. She was sent to the ward.

There is still an estimated postoperative disc recurrence around 7%, since the disc space is not completely shallow.

This is the 193d 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 severely affected nerve improved dramatically.

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.

After the 172d case, the elevation of motor stimulation above 5 V was abandoned to avoid delayed dural tear with subsequent CSF leak, which take place at the contact at the lower electrode shaft with the dura below the level of the axilla.