The patient came to the clinic 03-October-2019 complaining of LBP after falling down 03-September-2019. Three days later got numbness both lower limbs with weak and pain left upper limb. Intermittent claudication. MRI lumbar spine performed 16-September-2019, bad quality, showing extruded disc L5-S1 with stenosis. CT-scan lumbar area performed 17-September-2019 showing normal facets, no overmobility and myodil contrast at the bottom of the dural sac from myelography performed 40 years ago. The patient underwent discectomy twice for extruded disc L5-S1 40 years ago. The patient has diabetes mellitus and hypertension for 30 years. Stinting 1 year ago. He has spring allergy. 

On examination: He is in moderate pain, limping with exaggerated scoliotic stance. SLRS was 45 degrees both sides with tightness. There was weak dorsiflexion left foot -4/5 and planterflexion both feet 3/5.

The patient was sent for investigations: MRI whole spine done 05-October-2019 showed OPLL cervical spine with mild stenosis C5-6, small PDD D7-8 more to the right and severe stenosis L4-5 and L5-S1 with extruded disc L5-S1. The patient was sent to cardiac consultation and to stop anticoagulants for 7 days before surgery.

Decompressive laminectomy L4 L5 and partial of lower L3. Foraminotomy both L5 and S1 roots. All the compressive elements were drilled out and inspection of the disc showed hard bulge disc L5-S1. It was decided to leave the disc without violating it. Using MultiGen, bipolar motor stimulation of the left L5 root was achieved with 2.8 Volts . The right did not show response even to 4 Volts. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to both mentioned roots root  was achieved using 4 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the left L5 was achieved with 2.6 Volts, for the right L5 with 4 Volts. The patient was put in Reverse Trendelenburg position with Valsalva maneuver and hyperventilation. No CSF leak. Routine closure of the wound.

Smooth postoperative recovery. The power of both feet normalized and the sciatica disappeared. He was sent to the ward.

The patient is complaining of lumbar canal stenosis signs for what such strategy was undertaken.

This is the 187th 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 severely affected nerves improved dramatically after 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 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.

After the 172d case, the elevation of motor stimulation above 5 V was abandoned to avoid delayed dural tear with subsequent CSF leak, which take place at the contact at the lower electrode shaft with the dura below the level of the axilla.