The patient came to the emergency Shmaisani hospital 22-November-2022 with history of LBP for 10 years with right sciatica with exacerbation last 2 weeks. He is in agonizing pain. MRI lumbar spine done 22-November-2022 showing huge extruded disc L5-S1 with far-right downward sequestration. The patient is a known hypertensive with diabetes for 15 years with bronchial asthma for 6 years in inhaler. 

On examination, the patient is in agonizing pain, limping with exaggerated scoliotic stance. SLRS was 40 degrees right side with pain and 80 degrees left side without pain. There is weak dorsi and planterflexion right foot -4/5 with hypalgesia right S1 root. 

Cardio and pulmonary consultation was requested and they agreed low risk for G.A.

Right S1 foraminotomy with right sided removal of the extrusion lateral to the axilla and subaxillary attempt to remove the far-downward migrating piece was impossible, because the adhesion of the piece to the root, for what it was pushed up and removed lateral to the axilla, and right sided cleaning L5-S1 disc space. Using MultiGen, bipolar stimulation of the right S1 root was responding to 1.7 Volts. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to the right S1 root  was achieved using 2 bended catheters 10 mm exposed length. Further bipolar stimulation of the right S1 root was responding to 1.2 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 246th 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 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.