The patient came to the clinic 05-October-2017 complaining of LBP for 6 years with gradual deterioration and left sciatica the last 6 months with pareasthesia and inability to walk more than 150 meters.

On examination, the patient was limping with exaggerated scoliotic stance. There was weak dorsiflexion both feet 4/5 and SLRS was 75 degrees both sides with pain in the left.

The patient then came 03-May-2018 telling that she got more deterioration.

The patient was sent for investigations and MRI lumbar spine done 03-May-2018 showing spondylolisthesis L4-5 with severe segmental stenosis at this level. Dynamic studies showed spondylolisthesis L4-5.

Skeletonization of L3,4,5 down to the lateral processes. Transpedicular fixation of L4,5 using Legacy F.A.S 2 screws 6.5x45 mm to L5 and 2 screws 6.5x50 mm to L4 vertebrae. After inserting the screws motor stimulation 8 V was applied to all screws and there was no response. Foraminotomy of both L5 roots was achieved. Using MultiGen, bipolar motor stimulation of the left L5 root was achieved with 0.8V. The right L5 to 0.8V. 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 motor stimulation of the left L5 root was achieved with 0.7V. The right L5 root with 0.8 V. Reduction distraction fixation of L4-5 was achieved.  Routine closure of the wound.

Smooth postoperative recovery. The power of both feet became normal. She was sciatica free. She was sent to the ward.

This is the 149th 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 affected root after application was slightly 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.