The patient came to the clinic 11-December-2017 complaining of LBP with right sciatica for 2 month with exacerbation last month. The patient has diabetes mellitus. MRI lumbar spine performed 11-November-2017 showing extruded disc L4-5 central.

On examination, the patient is limping with scoliotic stance. SLRS was 40 degrees in the right with pain and 90 degrees in the left. There was weak dorsiflexion right foot 3/5, planterflexion same foot 4/5 with analgesia right L5 and S1 roots territory. The patient was sent for investigation and MRI lumbar spine performed 12-December-2017 showing extruded disc L4-5 with right foraminal occlusion. Dynamic studies and CT-scan were normal. The patient came telling that she improved upon prescribed medication, for what she was kept in conservative treatment. The patient then came 08-January-2018 telling that she has dramatic deterioration the last week with agonizing right sciatica and limping. SLRS was 80 degrees with pain in the right. There is drop right foot for 2 weeks with hypalgesia of the right L5 territory. MRI repeated the same day showing further enlargement of the extrusion with right foraminal occlusion and downward migration.

Foraminotomy of right L5 root was achieved. The extruded disk was removed lateral to the axilla from right side. Right sided intradiscal cleaning of L4-5 disc space was performed. For the future project, an hexagonal Allen key No 4 was with resistance going inside the annulus fibrosis defect, but No 5 was not possible. Using MultiGen, bipolar motor stimulation of the right L5 root was achieved with 1.3 V, but the response was planterflexion. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to the right L5 root was achieved using 2 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the right L5 was achieved with 1.0 V. Routine closure of the wound.

Smooth postoperative recovery. The power of the right ankle dorsiflexion improved, but the drop toe still the same. 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 141st 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 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.

Here the drop big toe remained the same, despite the fact that the root was responding well. Time will give the answer.