The patient came to the clinic 23-June-2018 complaining of left sciatica for three months with numbness all toes left foot. He was operated in Saudia 16 years ago for extruded disc L5-S1 twice, during the second a cage was inserted from the right side to the L5-S1 disc space. MRI lumbar spine performed 07-February-2018 showing extruded disc L4-5 and residual of the performed operation at L5-S1.

On examination was limping with exaggerated scoliotic stance. SLRS was 75 degrees right side and 40 degrees left side with pain. There is dorsiflexion left foot -4/5.

The patient was sent for investigations and MRI lumbar spine done 23-June-2018 showing extruded disc L4-5 with left foraminal occlusion and downward migration. Dynamic studies ruled out overmobility.

Foraminotomy left L5 root  with removal of the extrusion and left sided cleaning L4-5 disc space. Using MultiGen, bipolar motor stimulation of the left L5 root was achieved with 0.8 V. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to the left L5 root was achieved using 2 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the left L5 root was achieved with 0.8 V. Routine closure of the wound.

Smooth postoperative recovery. The power of the left foot became normal. He was sciatica free. He 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 154th 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.