The patient came to the clinic 27-July-2017 complaining of LBP with left sciatica for 1 month, then progressed to right sciatica the last week down with numbness all toes right foot.

On examination, the patient is in agonizing pain, limping with exaggerated  scoliotic stance. SLRS was 30 degrees with pain in the right and 40 degrees in the left. There is weak dorsiflexion both feet 4/5.

The patient was sent for investigations and MRI lumbar spine performed 29-July-2017 showing huge extrusion L4-5 with right downward migration. Dynamic studies ruled out overmobility and Lab investigations showed ESR 25 mm/h. The patient was advised to start Zinnat 500 mg twice a day to minimize the postoperative infection rate.

Foraminotomy of right L5 roots was achieved. The extruded disk was far downward migrating in comparison to the last MRI about 10 mm below the disc space. It was removed far away from the axilla of the right L5 root. Right sided intradiscal cleaning of L4-5 disc space was performed. The right L5 roots were full of veins, which were coagulated to achieve proper hemostasis and inspected to rule out any remnants of extrusion. Using MultiGen, bipolar motor stimulation of the right L5 was achieved with 0.39 V. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to right L5 root was achieved using 2 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the right L5 root was with 0.34 V. Routine closure of the wound.

Smooth postoperative recovery. The power of both feet normalized and she was sciatica free. She was sent to the ward.

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

This is the 128th 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 stimulation power of motor stimulation of the root after application was better.

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.