The patient came to the clinic 17-January-2017 complaining of LBP and right sciatica for 20 days with numbness all toes right foot. He was operated elsewhere for PLD L4-5 for right sciatica 20 years ago. MRI lumbar spine performed 02-January-2017 showing recurrent disc L4-5 with right upward migration.

On examination, the patient is not limping with mild scoliotic stance. SLRS was 50 degrees in the right and 65 degrees in left side with pain both sides. There is weak right foot dorsiflexion -4/5, planterflexion same foot -5/5. The patient has very long incision extending to the coccygeal region.

The patient was sent for new investigations and dynamic studies were uneventful.

Right L4 neurolysis and foraminotomy was achieved. The Level of the L4-5 was identified with scarolysis of the right L5 root. The extruded disk was removed lateral to the axilla under the L4 root. Right sided cleaning of L4-5 was performed. Using MultiGen, bipolar motor stimulation of the right L4 was achieved with 1.8 V. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to the right L4 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 in the right L4 with more brisk response. The right L5 root was not scarolysed since it was below the operative activity. 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 re-recurrence less than 7%, because the disc space is shallower than before.

This is the 101st 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, but adhesions were relatively minimal around the root, for what considerable improvement was achieved.