The patient came to the clinic first time 07-January-2003 complaining of both knees pain for 2 months without LBP. She had hypertension for 1 year and had episode of TIA involving the left cerebral hemisphere. On examination at that time, she had aseptic arthritis left knee. The patient was treated conservatively and sent for investigation and came 25-January-2003 with MRI lumbar spine showing LCS L4-5, L5-S1. The patient was advised to undergo surgery after resolution of the arthritis. The patient then came 18-August-2019 telling that she performed total knee replacement left knee 5 years ago and open heart surgery 7 years ago, complaining of left agonizing sciatica for 5 months. MRI both thighs performed 29-July-2019.

On examination: She is in agonizing pain, limping with exaggerated scoliotic stance. SLRS was 70 degrees right side without pain and 70 degrees in the left with severe pain. There is edema both legs. There was weak dorsiflexion both feet -4/5.

The patient was sent for investigations: MRI lumbar spine performed 20-August-2019 showing spondylolisthesis L4-5 with severe stenosis. Dynamic studies confirmed presence of grade II spondylolisthesis L4-5. Lab investigations showed Hb 10.7 WBC 6.3 and ESR 40 mm/h. The patient was advised to start antibiotics before surgery and to be evaluated by cardiologist and to stop anticoagulant one week before surgery.

Skeletonization L4.5 down to the transverse processes. Transpedicular reduction fixation L4-5 using Kasios 6x45 mm fixed screws. Decompressive laminectomy L4-5 with foraminotomy both L5 roots. Using MultiGen, bipolar motor stimulation of the right L5 root was achieved with 2.7 V. The left L5 root was achieved with 2.4 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 motor stimulation of the right L5 root was achieved with 1.4 V. The left L5 root was achieved with 1.4 Volts. The patient was put in Reverse Trendelenburg position with Valsalva maneuver. No CSF leak. Routine closure of the wound.

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

The patient over the years changed her clinical status and at this time transpedicular fixation and decompression is a must.

This is the 186th 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 severely affected nerves improved dramatically 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.