The patient came to the clinic 08-September-2022 with history of LBP for 12 years with exacerbation last 7 months with left sciatica and numbness of the left foot. He is in agonizing pain. MRI lumbar spine performed at KHMC 06-September-2022 reported to have huge extruded disc L4-5. The CD or films were unavailable.

On examination, the patient is in agonizing pain, limping with exaggerated scoliotic stance. SLRS was 80 degrees right side without pain and 2 degrees left side with severe pain. There is weak dorsiflexion left foot 3/5 and planterflexion same foot 4/5, with analgesia left L5 and S1 territories. 

The patient was sent for investigations and MRI done 17-September-2022 showing the huge extruded disc L4-5 with left foraminal occlusion.

The patient then came 18-September-2022 to the Emergency urging for surgery.

After intubation and turning the patient to Wilson frame, the FO2 became low, for what he was retuned to the normal position and the tube was changed, and a lot of pus came and the right lung was full of secretion. The patient is a heavy smoker and he had flue 3 days ago. After cleaning of the right lung, the patient was put back to Wilson frame and the operation proceeded. Left L5 foraminotomy with left sided removal of the extrusion and left sided cleaning L4-5 disc space. During that, the dura was torn and CSF leak took place. The bone around the dural tear was extended to catch the upper edge of the dural defect and using prolyn 6 zero the dural tear was repaired at the upper edge of the axilla. Using MultiGen, bipolar stimulation of the left L5 root was responding to 0.84 Volts. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to the left L5 root  was achieved using 2 bended catheters 10 mm exposed length. Further bipolar stimulation of the left L5 root was responding to 0.52 Volts. The patient was put in Reverse Trendelenburg position with Valsalva maneuver and hyperventilation. No CSF leak. For more security a piece of muscle was added above the torn and repaired dura. Smooth postoperative recovery. The power of the left foot improved. He was sent to the ward.

The patient progressed full blown cauda equina syndrome after surgery with inability to control urination and loss of defecation sensing. A huge amount of urine around 4 liters came with Foley's catheter. The power of the feet was normal, but there is hypalgesia of the left S1 and S1. The patient was kept for three postoperative days, during which he showed dramatic rapid recovery.

The patient then came 10 days after surgery with full control of defecation and urination with slight hypalgesia at the left side of the anal region.

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

This is the 243d 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.

In case that the patient has flue, it is preferable to postponed surgery for at least 2 weeks, but the patient came to the Emergency with agonizing pain urging for surgery.