The patient came to the clinic 07-August-2018 complaining of LBP for 2 months with right sciatica. 15 days ago got numbness all toes right foot. The patient noticed difficult micturition.

On examination: He is limping with scoliotic stance. SLRS was 40 degrees right side with pain and 70 degrees in the left shooting to the right side. There was weak dorsiflexion right foot -4/5 and planterflexion same foot 4/5. There is hypalgesia right L5 root territory. The right AJ is absent.

The patient was sent for investigations and MRI lumbar spine performed 07-August-2018 showing extruded disc L5-S1 with right downward migration. Dynamic studies ruled out overmobility and CT-scan of the area was uneventful.

Foraminotomy right S1 root  with removal of the extrusion and right sided cleaning L5-S1 disc space. Using MultiGen, bipolar motor stimulation of the right S1 root was achieved with 2.0 V. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to right S1 root was achieved using 2 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the right S1 root was achieved with 1.8 V. Routine closure of the wound.

Smooth postoperative recovery. The power of right foot 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.

This is the 163d 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 moderately.

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.