The patient came to the clinic 08-February-2022 complaining of LBP with left sciatica for 4 months, numbness both feet and edema right foot when standing a while. The patient was operated 2010 and 2018 for extruded disc L4-5. MRI lumbar spine done 30 -September-2021 showing huge recurrence L4-5.

On examination, the patient now is limping with scoliotic stance. Using crutches for 1 month. SLRS was 70 degree left side with pain. There is weak dorsiflexion both feet and planterflexion right foot. The weakness of the right foot was after performed previous surgeries. There is hypalgesia right L5 and S1 with numbness of the left S1 root.

The patient was sent for investigations and MRI done 08-February-2022 showing huge extruded disc L4-5, wide based with old one in the right and fresh one in the left.

Foraminotomy with scarolysis both L5 roots with removal of the extrusion from the left side. Intradiscal cleaning L4-5 both sides lateral to the root. Using MultiGen, bipolar stimulation of the left L5 root was achieved with 1.1 Volts. bipolar stimulation of the right L5 root was achieved with 3.7 Volts. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to both L5 roots  was achieved using 4 bended catheters 10 mm exposed length. Further bipolar stimulation of the left L5 root was achieved with 0.9 Volts. bipolar stimulation of the right L5 root was achieved with 2.4 Volts. The patient was put in Reverse Trendelenburg position with Valsalva maneuver and hyperventilation. No CSF leak. Smooth postoperative recovery. The power of both feet normalized. He was sent to the ward.

Too early now.

There is still an estimated postoperative re-recurrence around 7%, because the disc space is not shallow.

This is the 232d 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 nerves showed 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.