The patient was operated by me 08-March-2010 for PLD L3-4 and did well. The patient then came several times for different reasons, among them herpes Zoster neuritis of the right L 1 root in 26-November-2011 and treated accordingly. The patient then came to the clinic 09-Februaryl-2017 complaining of LBP with left sciatica with exacerbation last 3 months and inability to walk more than 100 meters.

On examination at that time, the patient is in agonizing pain, limping with mild scoliotic stance. SLRS was 80 degrees without pain in both sides. There is weak dorsiflexion left foot 3/5, and planterflexion left foot 4/5 with hypalgesia below the left knee.

The patient was sent for investigations and MRI lumbar spine performed the same day showing extruded disc L4-5 with left foraminal occlusion. Dynamic studies ruled out overmobility of the spine, but ESR was 47 mm/h and CRP was 7 mg/L. The patient had UTI for what antibiotic treatment was started. The patient then came 23-April-2017 after cardiologic evaluation and new MRI of the spine requested confirming the same previous data. ESR was 28 mm/h and CRP was 6 mg/L. 

Foraminotomy of the left L5 root was achieved. There is slight mobility of the L4 spinous process. The extruded disk was removed lateral to the axilla of the left L5 root. It was noticed from the start, that the dura was transparent at the point of maximum compression and all precautions were paid to avoid CSF leak. Left sided intradiscal cleaning of L4-5 disc space was performed. The left L5 root was inspected to rule out any remnants of extrusion. Using MultiGen, bipolar motor stimulation of the left L5 was achieved with 1.2 V. Waiting 4 minutes the same procedure repeated and bipolar motor stimulation of the left L5 was achieved with 1.1 V. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to left L5 root was achieved using 2 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the left L5 was achieved with 0.9 V. Valsava maneuver was applied to rule out CSF leak. A piece of muscle was applied over the transparent dura anterior to the axilla. Routine closure of the wound.

Smooth postoperative recovery. The power of left foot normalized and she was sciatica free. She was sent to the ward.

The patient still having an estimated postoperative recurrence around 7%, because the disc space is still not shallow.

This is the 116th 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 there was considerable improvement of the threshold of stimulation power of motor stimulation of the left L5 root.

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. This trail was performed intentionally to confirm or exclude such this conclusion. Here we noticed that the motor response of the nerve improved after first stimulation, confirming that the improvement came as a result of previous stimulation and BPRF still adding further improvement.