The patient came to the clinic 25-July-2018 complaining of LBP for 10 years with numbness right leg for 6 years after performed chemotherapy for Ca liver 2008. The patient was investigated repeatedly with whole body CT-scan with F18 FDG positron  emission tomography confirming stabilization of the disease. The last one was done 28-July-2017. The patient is hypertensive for one year under treatment.

On examination: He was not limping with scoliotic stance. SLRS was 30 degrees right side with pain and 75 degrees in the left side. There was weak dorsiflexion both feet 4/5.

The patient was sent for investigations and MRI lumbar spine performed 25-July-2018 showing extruded disc L4-5 with severe segmental stenosis. There is bulge disc D2-3 and D7-8. Dynamic studies ruled out overmobility and CT-scan of the area was uneventful. The patient refused to undergo complete workup but he was sent for cardio-pulmonary evaluation.

Decompressive laminectomy of L4 and upper half of L5. Foraminotomy both L5 roots  with removal of the extrusion and left sided cleaning L4-5 disc space. Using MultiGen, bipolar motor stimulation of the right L5 root was achieved with 5.3 V, bipolar motor stimulation of the left L5 root was achieved with 4.8 V. 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 3.4 V bipolar motor stimulation of the left L5 root was achieved with 3.0 V. Routine closure of the wound.

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

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

Due to the performed previous chemotherapy, the patient complains are atypical, even the stimulation threshold was very high as in this case.

This is the 161st 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 improved considerably.

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.