19-NOVEMBER-2025  ABDELRAHMAN ZAKI AZZAZI  53 YEARS  HUGE EXTRUDED DISC L4-5 WITH WIDE-BASED EXTRUSION AND SECONDARY STENOSIS.

The patient came 12-November-2025 complaining of agonizing right sciatica down to the heel right foot for 2 months with LBP. MRI lumbar spine done 20-October-2025 showing huge extruded disc L4-5 wide based with secondary stenosis.

On examination, the patient is limping with scoliotic stance. SLRS right side was 75 degrees with pain and 75 degrees in the left with pain shooting to the right. There is  weak dorsi and planterflexion right foot 4/5 same foot. No sensory deficit, but numb right foot.

The patient performed new MRI done 15-November-2025 confirming the presence of severe stenosis L4-5 with wide based extrusion. Dynamic studies ruled out overmobility. Lab investigations were uneventful. CRP was negative, ESR 5 mm/h.

The level of L4-5 was identified and laminectomy of lower half of L4 and upper half of L5 with foraminotomy both L5 roots was done.  Bilateral L4-5 disc cleaning was done with removal of the extrusion from both sides. Using MultiGen, bipolar stimulation of the right L5 root did not responded even to 3.5 Volts, bipolar stimulation of the left L5 root did not responded even to 3.5 Volts. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to the both L5 roots  was achieved using 4 bended catheters 10 mm exposed length. Further bipolar stimulation of the right L5 root did not responded even to 3.5 Volts, bipolar stimulation of the left L5 root did not responded even to 3.5 Volts. Direct muscle stimulation with 10 volts did not responded for what the anesthesia team which was changed last 4 months was noted to not use muscle relaxants in such surgery. The patient was put in Reverse Trendelenburg position with Valsalva maneuver and hyperventilation. No CSF leak. Routine closure of the wound. The patient showed dramatic recovery. He was sent to the ward.

Too early now.

The extruded disc was occluding both L4-5 foramens.

This is the 293d case using the MultiGen. This procedure regained routine acceptance.  It became a usual part of the spine and peripheral nerves surgery. Click here for reference. The patient showed no improvement of the motor stimulation after BPRF because the patent was put in muscle relaxant.

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.

Before doing motor stimulation in peripheral nerve surgery with tourniquet. always release the tourniquet before performing motor stimulation.