The patient was treated by me for chemical injury to the right sciatic nerve 12-June-2012 and fully recovered. Then he came to the clinic 31-January-2022 complaining of LBP for 45 days with left sciatica, numbness left foot for 10 days. He has headache for 15 days with attacks of sleepiness during driving.

On examination, the patient now is limping with scoliotic stance. Using crutches for 1 month. SLRS was 30 degree left side with pain. There is weak dorsiflexion left foot. There is hypalgesia both S1 roots territory with numbness of the left S1 root.

The patient was sent for investigations and MRI of the brain requested, showing only polyp left maxillary sinus and lumbar spine done 02-February-2022 showing huge extruded disc L5-S1 with left foraminal occlusion.

Foraminotomy left S1 root with removal of the extrusion from the left side. Intradiscal cleaning L5-S1 left side lateral to the root. Using MultiGen, bipolar stimulation of the left S1 root was achieved with 3.5 Volts. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to the left S1 root  was achieved using 2 bended catheters 10 mm exposed length. Further bipolar stimulation of the left S1 root was achieved with 2.5 Volts. The patient was put in Reverse Trendelenburg position with Valsalva maneuver and hyperventilation. No CSF leak. Smooth postoperative recovery. The power of the left foot normalized. He was sent to the ward.

Too early now.

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

This is the 233d 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.