The patient A Yemeni citizen came to the clinic 71-May-2022 complaining of LBP and right sciatica the last 5 months down to the right ankle joint. MRI lumbar spine performed today showing huge extruded disc L4-5 with right downward migration and severe segmental stenosis.

On examination, the patient is in agonizing pain, limping with scoliotic stance. SLRS was 80 degrees right side with pain and 80 degrees left side with more pain shooting to the right. There is weak dorsiflexion right foot 4/5. 

The patient was sent for investigations and lab investigations and ESR and CRP were normal.

Decompressive laminectomy L4-5 with right foraminotomy L5 root. Removal of the extrusion from the right and right sided cleaning L4-5 disc space. Using MultiGen, bipolar stimulation of the right L5 root was responding to 1.1 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 0.8 Volts. The patient was put in Reverse Trendelenburg position with Valsalva maneuver and hyperventilation. No CSF leak. Smooth postoperative recovery. 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 240th 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 is 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 the level of the axilla.