The patient came to the clinic 28-February-2018 complaining of LBP for three years with right sciatica for 6 months down to the gastrocnemius muscle. MRI lumbar spine performed 18-December-2017 showing extruded disc L3-4 central more to the left. The patient performed gastric band recently.

On examination was limping with scoliotic stance. SLRS was 60 degrees right side with pain shooting to the other side and 70 degrees left side without pain. There was weak dorsiflexion both feet 4/5. The left KJ was absent. The patient was sent for investigations and MRI lumbar spine performed 28-february-2018 showing huge extruded disc L3-4 more to the left. The dynamic studies were uneventful. The patient has gout. ESR was 23 mm/h and CRP was 16 mg/L. The patient telling that she was improved with prescribed medications, for what it was agreed to keep in conservative treatment. The patient then came 25-June-2018 with dramatic deterioration after travelling in April-2018. MRI repeated 21-June-2018 showing very huge extruded disc L3-4 causing complete obstruction of the level. On examination, she was limping with scoliotic stance. SLRS was 5 degrees in the right with pain and 10 degrees in the left with pain shooting to the right. Both KJs are absent and weak dorsiflexion both feet -4/5. 

Foraminotomy both L4 roots  with removal of the extrusion and bilateral cleaning L3-4 disc space. Using MultiGen, bipolar motor stimulation of the left L4 root was achieved with 0.9 V, bipolar motor stimulation of the right L4 root was achieved with 1.6 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 4 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the left L4 root was achieved with 0.9 V, bipolar motor stimulation of the right L4 root was achieved with 1.3 V. Routine closure of the wound.

Smooth postoperative recovery. The power of the feet became normal. She was sciatica free. She 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 156th 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.

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.