The patient came to the clinic20-December-2022 with right sciatica for one year with exacerbation last 2 weeks.

On examination, the patient is in agonizing pain, limping with exaggerated scoliotic stance. SLRS was 90 degrees right side with pain and 90 degrees left side without pain. There is weak dorsiflexion right foot 3/5 with hypalgesia right L5 root. Micturition and defecation problems for 2 weeks.

The patient was sent for investigations and MRI lumbar spine done 20-December-2022 showing bulge L3-4, L5-S1 and huge extruded disc L4-5 with right downward migration.

Right L5 foraminotomy with right sided removal of the extrusion lateral to the axilla and subaxillary to remove the far-downward migrating piece and right sided cleaning L4-5 disc space. Using MultiGen, bipolar stimulation of the right L5 root was not responding even to 4 Volts. 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 stimulation of the right L5 root was responding to 3.2 Volts. The patient was put in Reverse Trendelenburg position with Valsalva maneuver and hyperventilation. No CSF leak. The power of the right foot improved. He was sent to the ward.

Too early now.

The recurrence rate here is around 7%, because the disc space is not shallow.

This is the 247th 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 nerve did not respond to 4 Volts but improved moderately in 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.