The patient an Iraqi citizen, came to the clinic 07-March-2023 with LBP and right sciatica for 2 months and bilateral for 1 month with numbness both feet. MRI done 05-March-2023 showing severe lumbar canal stenosis with bulge disc L4-5.

On examination, the patient is in agonizing pain, limping with exaggerated scoliotic stance. SLRS was 60 degrees both sides with pain in the right side. There is weak dorsiflexion both feet 4/5.

The patient was sent for investigations and dynamic studies ruled out overmobility. Lab investigations were uneventful. Cardio consultation was asked.

Decompressive laminectomy L4 lower 3/4 and upper third of L5 with foraminotomy both L5 roots with inspection of the annulus fibrosis of L4-5. It was decided not to violate the disc because there is no extrusion. Using MultiGen, bipolar stimulation of the right L5 root was not responding even to 3.5 Volts, bipolar stimulation of the left L5 root was not responding even to 3.5 Volts. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to both L5 roots  was achieved using 4 bended catheters 10 mm exposed length. Further bipolar stimulation of the right L5 root was responding to 3.0 Volts, bipolar stimulation of the left L5 root was responding to 2.5 Volts. The patient was put in Reverse Trendelenburg position with Valsalva maneuver and hyperventilation. No CSF leak. The power of the feet normalized. He was sent to the ward.

Too early now.

The sooner the decompression, the better the outcome in progressive severe stenosis.

This is the 253d 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. The nerves improved to motor stimulation after performed BPRF.

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 was 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 5 minute session in most cases.

After the 172d case, the elevation of motor stimulation above 5 V was abandoned to avoid delayed dural tear with subsequent CSF leak, which take place at the contact at the lower electrode shaft with the dura below or above the level of the axilla.