The patient came to emergency of Shmaisani hospital with agonizing left sciatica for three days. He had right sciatica 3 months ago which subsided. The patient is overweight 150Kg. MRI done to the patient 04-July-2020 showing huge extruded disc L4-5 fulfilling the canal causing secondary stenosis with bulge L5-S1 right side. The patient relatives then came to the clinic 05-July-2020 telling that he could not come to the clinic due to severe pain. Lab investigations were requested and they were uneventful.

On examination at the operating room: The patient is in agonizing pain has almost drop  and weak planterflexion left foot -3/5. SLRS was 30 degrees with pain in the left. There is hypalgesia left S1 root territory.

Left L4-5 hemiflavotomy with extended left L5 foraminotomy. The extruded disc severely compressing the dura that it was causing a tear at the upper corner of the operative exposed part of the dura. The extruded disc was removed lateral to the axilla and the fragment under the root was removed after what the the root became relax. Left sided intradiscal cleaning L4-5 was achieved. Using MultiGen, bipolar motor stimulation of the left L5 root was achieved with 1.1 Volts. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to the left L5 root  was achieved using 2 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the left L5 root was achieved with 0.8 Volt. The patient was put in Reverse Trendelenburg position with Valsalva maneuver and hyperventilation. No CSF leak from the torn dura. This site was aided with muscle piece. Routine closure of the wound.

Smooth postoperative recovery. The power of left foot improved. He is sciatica free. He 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 200th 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 severely affected nerve 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.

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.