The patient came to the hospital 21-January-2017 complaining of LBP for three years with exacerbation last 3 months and right sciatica and agonizing pain for 3 weeks. MRI lumbar spine performed the same day showing huge extruded disc L5-S1 with right downward migration. The patient is a known diabetic for 4 years in treatment.

On examination, the patient is in agonizing pain, limping with exaggerated scoliotic stance. SLRS was 33 degrees right side with pain. There is weak right foot dorsiflexion 4/5, dorsiflexion same foot 4/5 and hypalgesia right S1 territory.

Right S1 foraminotomy was achieved. The Level of the L5-S1 was identified. The extruded disk was removed lateral to the axilla under the S1 root. Right sided cleaning of L5-S1 was performed. Using MultiGen, bipolar motor stimulation of the right S1 was achieved with 0.8 V. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to the right S1 root was achieved using 2 bended catheters 10 mm exposed length. Further motor stimulation done to the same root and the response was 0.6 V with more brisk response. Routine closure of the wound.

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

The patient still having an estimated postoperative recurrence around 7%, because the disc space is still not shallow.

This is the 102d 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 tell that the electrodes did not migrate during the procedure and the nerve is functioning properly. Here there was considerable improvement of the threshold of stimulation power of motor stimulation after the 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 anaesthesia protocol also the same. In this case adhesions could be a factor for initial high voltage requirement to achieve motor response.