The patient came to the clinic 10-May-2018 telling that he progressed LBP the last 1 month with left sciatica which became bilateral with numbness both feet. The last day severe deterioration with inability to walk. The patient is a doctor and known diabetic.

On examination SLRS was 45 degrees with pain both sides. There is weak planterflexion both feet 4/5 and dorsiflexion right foot 3/5 and left foot 4/5 with weak right quadriceps and iliopsoas 4/5.

The patient was sent for investigations and MRI lumbar spine done 10-May-2018 showing huge extruded disc L3-4 with left upward migration. Dynamic studies ruled out overmobility.

Left L3,4 hemilaminectomy was performed with foraminotomy both L4 and L5 roots. The extruded disc of L3-4 was removed and intradiscal cleaning of L3-4 was achieved from the left. There was a tear in the lower field of the exposed dura, for what the exposure was extended and nylon 6 zero dural repair was performed and Valsalva with Trendelburg positioning was performed to rule out presence of CSF leak. Using MultiGen, bipolar motor stimulation of the left L3 root was achieved with 1.9 V, bipolar motor stimulation of the left L4 root was achieved with 0.5 V. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to the left L3 and L4 roots was achieved using 4 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the left L3 root was achieved with 1.8 V, bipolar motor stimulation of the left L4 root was achieved with 0.4 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.

This is the 152d 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 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.