Inomed Stockert Neuro N50. A versatile
RF lesion generator and stimulator for
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Multigen RF lesion generator .
09-MAY-2017 ZAKIYE UBAID MUHAMED 70 YEARS
SPONDYLOLISTHESIS L3-4 WITH SEVERE SEGMENTAL STENOSIS.
The patient came to the clinic complaining of
LBP with bilateral sciatica, more to the right
with deterioration the last 5 months with
numbness both feet and inability to walk more
than 100 meters.
On examination, the patient is limping with
exaggerated scoliotic stance. SLRS
was 15 degrees with pain in both sides. There is weak
dorsiflexion right foot -4/5, and dorsiflexion
left foot 4/5.
The patient was sent for investigations and MRI
lumbar spine performed the next day showing
spondylolisthesis L3-4 with severe segmental
stenosis. Dynamic studies confirmed the presence
of spondylolisthesis L3-4. The patient was sent
for cardio evaluation.
Skeletonization of the spinous
processes of L3,4 and partial of L5. Check
for instability was positive for L3 lamina.
Transpedicular distraction reduction fixation of
L3-4 was performed using OSI polyaxial screws 6.5x45
mm. The screws were checked by stimulation and 3 of
them were not responding even to 8 V stimulation.
The left upper screw showed motor response to 4.5 V.
The screw was adjusted to be directed more lateral.
Another attempt of stimulation was repeated and the
same motor threshold was noted. Decompressive
laminectomy of L3, 4 and upper third of L5 was
achieved. Foraminotomy of L3,4 both sides was
performed. The left L3 root was intact and the left
pedicle of L3 was intact medial and inferior. Using
MultiGen, bipolar motor stimulation of the right
L3 root was achieved with 0.9 V. The left
was achieved with 0.9 V. The right L4 root
respond to 0.9 V, the left L4 root respond to 0.9 V. Waiting 4 minutes the same procedure
repeated and bipolar motor stimulation of the
right L3 root was achieved with 1.2 V, the right L4 was with 1.3 V.
The left L3 root respond to 0.9 V and the left L4
root respond to 0.9 V. A
bipolar pulsed mode
RF with 42 Celsius, 240 sec, 2 Hz and 20 msec
duration to both L3 and L4 roots was achieved using
4 bended catheters 10 mm exposed length in 2
bipolar motor stimulation of the right L3 root
was achieved with 0.1.2 V, the left L3 was
with 0.5 V.
Right L4 root respond to 1.3 V and the left L4
root to 0.9 V. Cross connector Nemesis 38-50 mm was
applied. Harvested bone was applied lateral to the
bended rods. All stages of surgery were performed
with C-arm guidance.. Routine closure of the
Smooth postoperative recovery. The power of
both feet normalized and she was sciatica free.
She was sent to the ward.
The patient has several problems, which
require surgical correction, stenosis at 2 levels and
This is the 117th 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
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 there was considerable improvement of the threshold of stimulation
power of motor stimulation of all the involved roots.
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. This trail was
performed intentionally to confirm or exclude such this
conclusion. Here we noticed that the motor response of the
nerves improved after first stimulation, confirming that the
improvement came as a result of previous stimulation and
BPRF still adding further improvement.
It is well known that if the monopolar
stimulation of the screw is absent with 8 V, it means that
the screw is away from the neural elements. But in this case
the left upper screw showed response to 4.5 V. The fact that
the direct bipolar stimulation of the same involved root
showed good response to 0.4 V confirming that the 4.5 V
could be explained by leakage of currents through sufficient
distance without violating the walls of the pedicle.
The difference in motor stimulation of
the right side mostly due to change of electrodes