The patient came to the clinic 18-July-2018 complaining of LBP with left sciatica for 3 years with exacerbation last 2 weeks with numbness all toes left foot. Bad quality MRI performed 16-July-2018 showing as be extruded disc L3-4 and L5-S1. The patient claiming that she performed laminectomy 2 years ago for PLD L4-5 and she is receiving L-thyroxin 50 microgram daily for 2 years. 

On examination was limping with scoliotic stance. SLRS was 100 degrees both sides with pain in the left side. There was weak dorsiflexion left foot 3/5 and planterflexion same foot 4/5. The patient was sent for investigations and MRI lumbar spine performed 18-July-2018 showing extruded disc L5-S1 with left foraminal occlusion and downward migration.

Foraminotomy left S1 root  with removal of the extrusion and left sided cleaning L5-S1 disc space. Using MultiGen, bipolar motor stimulation of the left S1 root was achieved with 1.0 V. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to the left S1 root was achieved using 2 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the left S1 root was achieved with 1.0 V. Routine closure of the wound.

Smooth postoperative recovery. The power of the left foot 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 160th 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 the same.

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.