The patient came to the clinic 17-May-2020 with right sciatica for one year. He was operated elsewhere 2018 for extruded disc L4-5 for right sciatica. He was under treatment for epilepsy at 15 years age and stopped medication last 5 years. On examination at that time: MRI done 29-January-2020 showing broad based extrusion L4-5. He was not limping with minimal scoliotic stance. SLRS was 70 degrees right side with pain. The patient was sent for investigations and was treated conservatively. The patient then came 30-July-2022 telling that he was OK! until got deterioration of his right sciatica the last 3 weeks with numbness of his right foot. MRI done the same day showing huge recurrence of L4-5 with complete stenosis at this level. He was limping with severe exaggerated scoliotic stance. SLRS was 30 degrees right side with severe pain and 75 degrees left side with less pain shooting to the right. He had weak dorsiflexion right foot 4/5 with hypalgesia right L5 territory. He was advised to undergo surgery and given pain-killers. The patient is obese with 124 Kg weight.

The patient disappeared, but came 27-December-2022 urging for surgery and MRI done the same day showing the same huge extrusion.

The old incision was used with slight extension up and down. Right L5 foraminotomy with right sided removal of the extrusion lateral to the axilla and right sided cleaning L4-5 disc space. During neurolysis there was longitudinal partial tear medial to the axilla with the arachnoid scarous. To avoid CSF leak, bipolar coagulation of this part was applied. Using MultiGen, bipolar stimulation of the right L5 root was responding even to 1.5 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 stimulation of the right L5 root was responding to 1.1 Volts. The patient was put in Reverse Trendelenburg position with Valsalva maneuver and hyperventilation. No CSF leak. The power of the right foot improved. He was sent to the ward.

Too early now.

The re-recurrence rate here is around 7%, because the disc space is not shallow.

This is the 248th 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. The nerve responded to 1.5 Volts but improved moderately in motor stimulation after performed BPRF to 1.1 Volts.

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 was 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 5 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 or above the level of the axilla.