The patient was operated by me 03-May-2008 for LCS L4-5 with extruded disc L4-5. The patient then came 06-June-2018 with inability to walk more than 10 meters with bilateral sciatica more the left with gradual deterioration the last three months and edema and inability to flex the index right hand the last 2 months.

On examination was limping with exaggerated scoliotic stance. SLRS was 80 degrees right side and 60 degrees left side with pain. There is dorsiflexion right foot 4/5 and left foot -4/5 with hypalgesia left S1 root territory. There is severe osteoarthritis both knees with pain and limitation of flexion.

The patient was sent for investigations and MRI lumbar spine done 20-June-2018 showing severe stenosis L2-3 and  L3-4. Dynamic studies ruled out overmobility with presence of mild spondylolisthesis L4-5.

Decompressive laminectomy of L2,3 and remnants of L4 was performed with foraminotomy both L3 and L4 roots both sides. Valsalva maneuver with Trendelburg positioning was performed to rule out presence of CSF leak. Using MultiGen, bipolar motor stimulation of the left L3 root was achieved with 1.0 V, bipolar motor stimulation of the left L4 root was achieved with 0.7 V. Bipolar motor stimulation of the right L3 root was achieved with 0.8 V, bipolar motor stimulation of the right L4 root was achieved with 1.2 V. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to the left and right L3 and L4 roots was achieved using 4 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the left L3 root was achieved with 1.0 V, bipolar motor stimulation of the left L4 root was achieved with 0.7 V. Bipolar motor stimulation of the right L3 root was achieved with 0.8 V, bipolar motor stimulation of the right L4 root was achieved with 1.0 V. Routine closure of the wound.

Smooth postoperative recovery. The power of both feet became normal. She was sciatica free. She was sent to the ward.

LCS is a progressive condition. The sooner the surgical intervention in case of deterioration, the better the outcome.

This is the 153d 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 root after application was mostly the same.

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.