Inomed Stockert Neuro N50. A versatile
RF lesion generator and stimulator for
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Multigen RF lesion generator .
23-MAY-2017 FUAD ABDEL-LATIF AL-BULBUL 60 YEARS
SPONDYLOLISTHESIS L4-5 WITH SEVERE SEGMENTAL STENOSIS.
The patient came to the clinic 05-May-2010 complaining of
LBP for 5 months with bilateral sciatica, more
to the right. MRI lumbar spine performed
06-Jaanuary-2010 showing severe LCS L4-5. He
could walk for less than 300 meters. SLRS at
that time was 60 degrees right side with pain,
hypalgesia both L5 roots territory and weak
dorsiflexion both feet -4/5. The patient then
disappeared and came back 18-February-2017 with
clinical deterioration and inability to walk
more than 100 meters, LBP and bilateral sciatica
with intermittent claudication. MRI lumbar spine
performed 25-July-2016 showing severe segmental
stenosis L4-5. Dynamic studies showing II degree
spondylolisthesis L4-5. The patient now having
diabetes mellitus for 3 years with arterial
On examination, the patient is not limping with
exaggerated scoliotic stance and walking bended
was 50 degrees with pain right side and 15 degrees with pain in
the left. There is weak
dorsiflexion both feet -4/5. The patient then
was admitted 22-May-2017 and new MRI with
dynamic studies and lab investigations were
performed and cardio consultation was achieved.
Skeletonization of the spinous
processes of L3,4 and L5. Check
for instability was positive for L4 lamina.
Transpedicular distraction reduction fixation of
L4-5 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 right lower screw showed motor response to 1.5 V.
The screw was adjusted to be directed more lateral.
Another attempt of stimulation was repeated and the
right upper screw showed response to 3.4, for what
it was repositioned more lateral and more vertical.
The three screws now not responding even to 8 V
except the right lower screw responding to 4.5V. Decompressive
laminectomy of L4, and upper third of L5 was
achieved. Foraminotomy of L5 roots both sides was
performed. The right L5 root was intact and the right
pedicle of L5 was intact medial and inferior. Using
MultiGen, bipolar motor stimulation of the right
L5 root was achieved with 0.8 V. The left
was achieved with 1.5 V. A
bipolar pulsed mode
RF with 42 Celsius, 240 sec, 2 Hz and 20 msec
duration to both L5 roots was achieved using
4 bended catheters 10 mm exposed length in 2
bipolar motor stimulation of the right L5 root
was achieved with 0.8 V, the left L5 was
with 1.4 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 he was sciatica free.
He was sent to the ward.
The patient has several problems, which
require surgical correction, stenosis at 1 levels with
This is the 120th 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.
We stopped the previous experiments
confirming that there is no harm of the BPRF application and
will keep it for future drop foot as treatment.
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 0.8 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
upper right screw which in the first stage of stimulation,
did not respond to 8.0V, but later got response to 3.4V
could be anesthesia protocol troubleshooting. The propofol
could be to blame.
These data showing that the motor
response of the screws could be a parameter showing that the
far the root from the screw, the root will not respond even
to currents more than 8 V, even the anatomical structures
are not violated.