The patient was operated by me 29-November-2008 for wide based extrusion L4-5. The patient then came to the clinic 12-February-2018 complaining of LBP with right sciatica for 5 months down to the right foot. She is using crutches for one month. MRI lumbar spine performed 30-October-2017 showing extruded disc L3-4 with right foraminal occlusion. She is a known diabetic, with arterial hypertension in L-thyroxin 50 microgram for 2 years.

On examination, the patient is limping with scoliotic stance. SLRS was 85 degrees in the right with pain. There was weak dorsiflexion right foot -4/5, planterflexion same foot 5/5. The patient was sent for investigations and cardio consultation and MRI lumbar spine repeated 12-February-2018 showing the same extrusion. Dynamic studies were negative for overmobility.

Foraminotomy of the right L4 root was achieved. The extruded disk was removed lateral to the axilla from right side. Right sided intradiscal cleaning of L3-4 disc space was performed. For the future project, an hexagonal Allen key No 4 was with difficulty going inside the annulus fibrosis defect. Due to severe compression, there was a dural defect with intact arachnoid. One 6 zero nylon stitch was applied aided with muscle flap was inserted to avoid postoperative CSF leak. Using MultiGen, bipolar motor stimulation of the right L4 root was achieved with 2.1 V. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to the right L4 root was achieved using 2 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the right L5 was achieved with 1.6 V. Routine closure of the wound.

Smooth postoperative recovery. The power of the right foot became normal. 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 143d 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.