The patient came to the clinic 25-July-2020 telling that she was operated for lumbar disc 3 years ago with bilateral sciatica. The patient noticed mild improvement after surgery, but still having bilateral sciatica with numbness both feet and cannot walk more than 100 meters. She is a known diabetic and hypertensive for 5 years.

On examination, the patient is limping with exaggerated scoliotic stance. SLRS was 45 degrees with pain both sides. There is hypalgesia left L5 and S1 roots territories with weak dorsiflexion both feet: right 4/5, left -4/5.

The patient was sent for investigations. MRI dorsal and lumbar spine done 22-July-2020 showed severe stenosis L1-2 and L2-3.

The patient was treated conservatively and she came 01-March-2021 telling that she cannot walk more than 10 meters. On examination SLRS was 40 degrees with pain right side and 65 degrees with less pain in the left. The same hypalgesia of left L5 and S1 territories. There was severe OA both knees, more the left. The patient was sent for investigations and MRI lumbar done 07-September-2021 showing extruded disc L1-2 and L2-3 with segmental stenosis both level. The patient was sent for cardio evaluation and ESR 40 mm/h and CRP 10 mg/dL. Zinnat was started.

Decompressive laminectomy L2, upper part of L3 and lower half of L1. Foraminotomy L2,3 both sides. Inspection of the disc of L1-2 both sides and L2-3. Using MultiGen, bipolar motor stimulation of the right L2 root was achieved with 1.5 Volts, bipolar motor stimulation of the left L2 root was achieved with 1.0 Volt. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to both L2 roots  was achieved using 4 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the right L2 root was achieved with 1.0 Volt, bipolar motor stimulation of the left L2 root was achieved with 0.8 Volt. The patient was put in Reverse Trendelenburg position with Valsalva maneuver and hyperventilation. No CSF leak. A fat tissue with pedicle was used to cover the dura to minimize the postoperative scar formation and prevent postoperative CSF leak. Routine closure of the wound. Smooth postoperative recovery. The power of the feet improved. She was sent to the ward.

MultiGen

Too early now.

This is the 225th 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 motor stimulation of the affected nerve improved dramatically after BPRF, because it seems the root was severely compressed.

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 at least 5 minute 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.