The patient was operated by me 11-July-2017 for extruded disc C3-4 with severe compression of the spinal cord. The patient showed dramatic improvement of the clinical manifestations according to the cervical lesion. The patient then came to the clinic 22-September-2018 complaining of LBP  with left sciatica for several months.

On examination: She is limping with exaggerated scoliotic stance. Neck and upper limbs were free of pain or clinical manifestations. SLRS was 80 degrees right side and 70 degrees in the left with pain. There was weak dorsiflexion right foot 4/5, left foot -4/5 with weak planterflexion both feet 4/5. She is complaining of difficult control of defecation.

The patient was sent for investigations and MRI lumbar spine performed 22-September-2018 showing severe lumbar canal stenosis L4-5. Dynamic studies ruled out overmobility.

Decompressive laminectomy of L4 and upper half of L5 with bilateral foraminotomy. Using MultiGen, bipolar motor stimulation of the right L5 root was achieved with 2.5 V , left L5 root was achieved with 1.2 V. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to both L5 roots was achieved using 4 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the right L5 root was achieved with 2.0 V, left L5 root was achieved with 0.9 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.

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

This is the 169th 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 roots after application improved dramatically.

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.