The patient came to the clinic 20-April-2019 complaining of right sciatica since 1998 with subsequent improvement with difficult walking for many years , intermittent claudication and inability to walk more than 10 min. Using crutches the last month. MRI lumbar spine performed 29-May-2018 showing lumbar canal stenosis L2-3, 3-4 and bulge L4-5. The patient is known diabetic for 10 years with arterial hypertension for 7 years in medication. He is using baby aspirin.

On examination: SLRS was 70 degrees both sides with pain. There was weak dorsiflexion right foot -4/5 and hypalgesia both L5 and right S1 territories.

The patient was sent for investigations: MRI lumbar spine performed 20-April-2019 showing severe lumbar canal stenosis L1-2, 2-3 3-4 and occlusion of right L4-5 foramen. Lab investigations were uneventful except for ESR 40 mm/h and CRP 8 mg/L. The patient was advised for surgery and start immediately Zinnat 500 twice daily to decrease the possibility of postoperative infection, stop anticoagulant and to be seen by cardiologist.

Decompressive laminectomy L2,3,4, lower half of L1 and upper half of L5. Foraminotomy right L2,3,4,5 roots. Using MultiGen, bipolar motor stimulation of the right L4and L5 roots was achieved with 1.7 and 2.0 Volts respectively. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to both roots was achieved using 2 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the right L4and L5 roots was achieved with 1.0 and 1.5 Volts respectively with more brisk response. The patient was put in Reverse Trendelenburg position with Valsalva maneuver. No CSF leak. Routine closure of the wound. The patient was given 1 unit blood and 2 units FFP.

Smooth postoperative recovery. The power of the right foot improved and the sciatica disappeared. He was sent to the ward.

There is still an estimated postoperative re-recurrence around 7%, because the disc space height is still not shallow.

This is the 178th 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. Here the threshold of stimulation power of motor stimulation of the affected nerve improved after 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 4 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.