The patient came to the clinic 29-September-2021 complaining of LBP with right sciatica down to the right S1 root territory for 45 days. MRI lumbar spine done 07-August-2021 showing huge extruded disc L4-5 with right downward migration. He take baby aspirin once daily.

On examination, the patient in agonizing pain, limping with exaggerated scoliotic stance. SLRS 10 degrees right side with pain and 20 degrees left side with pain shooting to the right. There is weak dorsi and planterflexion right foot 3/5. The patient was advised to stop anticoagulant 7 days before surgery.

Foraminotomy right L5 root. The extruded disc was removed lateral to the axilla and right sided cleaning of L4-5 disc space was achieved. Using MultiGen, bipolar motor stimulation of the right L5 root was achieved with 2.7 Volts. 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 1.6 Volt. The patient was put in Reverse Trendelenburg position with Valsalva maneuver and hyperventilation. No CSF leak. A fat tissue with pedicle was used to cover the dura to minimize the postoperative scar formation and prevent postoperative CSF leak. Routine closure of the wound. Smooth postoperative recovery. The power of the right foot improved. He was sent to the ward.

Too early now.

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

This is the 226th 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 motor stimulation of the affected nerve showed dramatic improvement 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.

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.