The patient came to the clinic 10-February-2018 complaining of LBP with left sciatica for 6 years with exacerbation last 7 months down to the lateral malleolus. MRI lumbar spine performed 29-January-2018 showing extruded disc L4-5 central with left foraminal and downward migration.

On examination, the patient is limping with scoliotic stance. SLRS was 25 degrees in the left with pain. There was weak dorsiflexion left foot -4/5, planterflexion same foot 5/5. The patient was sent for investigation and ESR was 35 mm/h for what Zinnat was started before surgery.

Foraminotomy of the left L5 root was achieved. The extruded disk was removed lateral to the axilla from left side. Left sided intradiscal cleaning of L4-5 disc space was performed. For the future project, an hexagonal Allen key No 4 was with resistance going inside the annulus fibrosis defect, but No 5 was not possible. Using MultiGen, bipolar motor stimulation of the left L5 root was achieved with 1.38 V. 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 was achieved with 1.04 V. Routine closure of the wound.

Smooth postoperative recovery. The power of the left foot became normal. 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 142d 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.