The patient came to the clinic 09-June-2013 complaining of LBP  with right sciatica for 5 years with intermittent course and exacerbation of LBP and the right sciatica the last 2 months after lifting heavy object. MRI lumbar spine performed 22-April-2013 showing bulge L3-4, L4-5 and L5-S1. She got deterioration the last day. On examination at that time, she was limping with exaggerated scoliotic stance. SLRS was 80 degrees both sides with weak dorsiflexion right foot 3/5, planterflexion same foot 4/5. and hypalgesia right L5 and S1 territories. The patient was given pain killers and sent for investigations. The patient disappeared and came 20-December-2014telling that she got thyroid masses in both sides and and difficult walking with numbness right foot and left sciatica 6 months ago, which resolved. On examination at that time she was limping with same exaggerated scoliotic stance with same hypalgesia right foot and weak dorsiflexion right foot 3/5, planterflexion same foot -3/5. The patient was given pain killers and sent for investigations. MRI lumbar spine performed 23-Deember-2014 showing bulge L3-4, L4-5 and L5-S1. Dynamic studies ruled out overmobility. ESR was 47 mm/h. The patient then escaped and came 18-August-2018 telling that she progressed severe agonizing LBP the last 3 days with the usual bad quality MRI performed 18-August-2018 showing unreadable data. She is a known diabetic for 10 years using Insulin. She is using L-thyroxin 125 microgram daily.

On examination: She is limping with scoliotic stance. SLRS was 30 degrees right side with pain and 80 degrees in the left. There was drop right foot for 3 days with weak planterflexion same foot 4/5. There is also weak dorsiflexion left foot 4/5. There is hypalgesia right L5 and S1 root territory. The right AJ is absent.

The patient was advised to perform proper investigations and MRI lumbar spine performed 19-August-2018 showing extruded disc L3-4 with right far downward migration and right L4-5 foraminal occlusion. Dynamic studies ruled out overmobility and CT-scan of the area was uneventful. ESR was 30 mm/h CRP 9 mg/L. The patient was told that she needs urgent surgery and Zinnat was started. The patient then came to admission 26-Augut-2018.

Right L4 hemilaminectomy with partial laminectomy of L3 and L5. Foraminotomy right L4 and L5 roots with removal of the extrusion and right sided cleaning L3-4 disc space. Inspection of the L4-5 disc annulus fibrosis. Decided not to violate the disc structure. During foraminotomy of the right L4 root, before completing it, a sensory twig came out and inspected. The twig is coming from the posterior wall of the root 10 mm below the axilla. The twig was coagulated and sharply bisected. No CSF leak. Using MultiGen, bipolar motor stimulation of the right L4 root was achieved with 0.4 V. Bipolar motor stimulation of the right 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 right L4 and L5 roots was achieved using 4 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the right L4 root was achieved with 0.4 V. Bipolar motor stimulation of the right L5 root was achieved with 1.0 V. There was a tiny dural defect at the lower field of the dura. It was stitched with 6 zero nylon. The patient was put in Reverse Trendelenburg position with Valsalva maneuver. No CSF leak. A muscle with pedicle was applied over the right L4 root. Routine closure of the wound.

Smooth postoperative recovery. The power of left foot became normal. The drop left foot showed a slight improvement with normalization of planterflexion right foot. 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 165th 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 slightly.

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.

It is unclear why the structurally damaged L4 root was responding to very low threshold of stimulation.

The drop foot needs time to recover, if recovery taking place. Time in this case will tel.