| 619-543-5540 |
| Motor Cortex Stymulation |
Robert J. Buchanan, M.D. Assistant Professor of Surgery, Psychiatry and
Radiology, UCSD Medical Center, Division of Neurosurgery
Ph. 619-543-5540
Recap of December meeting 2005By Don Jeffries
Motor Cortex Stimulation (MCS)Dr. Buchanan may be the only neurosurgeon and
psychiatrist in the world! Dr. Buchanan is the pain neurosurgeon at the Medical
Center. I do all the operations for all the different pain syndromes along with the
microvascular decompression surgery the same as Dr. Alksne. By the way, Dr.
Alksne assisted Dr. Jannetta doing the first MVD ever done in the united states.
We have this new procedure call Motor Cortex Stimulation. (MCS)We will be doing a
kind of show and tell, rather than a slide show or a power point presentation. We will
be looking at things from a three dimensional point of view.
Motor means movement. One would think that it is counter intuitive, that doesn’t
make much sense to stimulate a part of the brain that controls movement. It would
be better to stimulate an area of the brain that has something to do with sensation.
That was tried, and when that part of the brain was stimulated that dealt with
sensation when it was stimulated with electricity, what happens is that people just
get an unusual feeling. It can also have a worsening of pain syndromes.With the
motor cortex stimulation (MCS), you can imagine if you stimulate an area of the
brain that causes one–half of your body to move, that one half of your body should
move, and indeed that is the case. If the stimulation energy is high enough and you
can make it high enough, that is part of the process of figuring out the best
parameters and numbers are and getting the patient up to the point where their
face of their arm will move depending where they have their pain. (Face, leg back
etc.) We get the arm or leg to move and then we slowly bring down the stimulation
intensity below the movement threshold or the motor threshold, that is where the
best pain relief is found, just below the movement threshold.How does it work? No
body really knows exactly how it works. The brain is not perfectly percolated Or
compartmentalized as one would imagine. There is not just one area of the brain
the deals with movement. The part of the brain that deals with movement also has
connections that deals the interpretation of movement. Also, what it feels like to
move, so the thought is that that area of the brain is highly connect with other areas
of the brain that have an affect on sensation. That is how Motor Cortex Stimulation
(MCS) came about.
There are only a few doctors that do this, we call ourselves functional
neurosurgeons. I do the surgery’s for epilepsy,for movement disorders usually
dealing with Parkinson’s, psychiatric disease, and for pain syndrome.Motor Cortex
Stimulation (MCS) is useful for many pain syndromes which includes TN. When
people have strokes, part of the brain dies because of a lack of blood and oxygen.
A part of the brain dies, usually in the tipper parts of the brain. That which dies is
inside the brain, that structure of the brain that is the great gate keeper of all
sensation. Everything that we experience in the environment comes through this
structure in the brain, called the thalamus. If you have a stroke in the thalamus you
can have really bad pain syndromes. Where as a rule these patients have
anesthesia delarosa, which can affect the entire one side of the body. As you can
imagine it is really debilitating. You have the pain on the side of your face, if you
can imagine the whole side of your body hurting like that all the time?
Who gets Motor Cortex Stimulation?
We generally do not do MCS on patients who have TN. It doesn’t seem to help
patients with Denovo "new TN."So that lancinating, sharp, stabbing, electrical like
pain isn’t really helped by MCS. It is patients who have had other things done and
have had that part of TN helped with the stabbing pain that this procedure may
help. Most of the pain can be gone, but often times you can be left with anesthesia
delarosa which is that condition that you do not have any sensation except pain,
burning pain and it is usually a chronic burning, throbbing pain. So those are the
patients that we can operate on as well as other patients with ‘atypical’ facial pain.
We would look at them for a possible implantation device.I have operated on 15
patients so far for the Motor Cortex implantation device. This is about as large a
series as any other place in the world. It is a relative new procedure. Initially it was
thought that this procedure was for the patients who had the strokes in the
thalamus.
But as it turns out from my own experience a UCSD it is the patients with failed
procedures of TN syndrome are responding best to the MCS procedure. Every
patient that we have implanted has experienced some relief from the pain.
We had one patient that said that the device was not responding real well that she
was still in pain. Although, during her visit we turned it off, and did not tell her that
we had turned it off. The MCS can be regulated by the doctor. It can be turned up,
down, or off. The patient does not know what you have done, they cannot tell if is
on or off, unless they feel the pain, then you turn it on, if the pain subsides, you
know it is working. If it doesn’t, you turn it up.As I said I had turned hers off. The next
day she called to say I must have turned it off because she was feeling pain. The
device did not cure her pain, but it cut it considerably.
I don’t really know how it is working. What we have found in a few patients is really
quite interesting. We are studying this because the area of the brain that this goes
on, where the motor cortex sits, is in what we refer to as in the frontal lobe. The
frontal lobe is what makes us who we are. It is where our personalities sit, our ability
to navigate through problems. Another thing that sits in the frontal lobe is our ability
to draw our attentions to things. It allows us to concentrate enough to not be
distracted by many things, that you are able to maintain your attention on the task.
The patients with frontal lobe damage through stroke, damage, or trauma has a
very difficult time concentrating, and maintaining their concentration and attention
on a task. And being a neurosurgeon/psychiatrist the issue that I am finding in the
patients is that: We have an individual whom I operated on who had a thalamic
stroke. He come in with is wife; he has lost weight, he has grandchildren etc.. His
problem was on the left side of his body. We tried to treat his left arm because, he
would never drive with his left arm, wouldn’t pick up his grand kids with his left arm
etc.. His wife said,"he is picking up his grand children with his left arm, he is driving
with both arms. But, if I ask him how is the pain in your hand and arm? He will look at
it and say it is still burning I can still feel the burning in my arm and my hand. I don’t
think it is a ten any more, but I think it is seven or an eight. Yet his whole life has
changed.What I am wondering is that it seems one’s attention to the pain is being
disrupted. The individual does not notice it unless you draw their attention to it. I
have not found this so much with facial pain patients. I have found this more with the
thalamic stroke patients and that may make sense for the reason that there is 10
billion nerve cells and each one of those nerve cells can make 10-20,000
connections.The facial patients can pretty well tell you that the pain is gone or has
subsided. The stroke patients are just distracted from the pain.
This procedure is only done in about twenty-five centers in the country.
How do I assess for Motor Cortex Stimulation?There are ways in the past that were
used to assess. They were found to be just as necessary today. Where patients
were given IV morphine or a barbiturate. As you know in a time of pain morphine is
not very helpful. Then they would give them the barbiturate IV, and this kind of pain
tends to respond to barbiturates for a short period of time. This was the initial test
they used. Patients that responded to the barbiturate and not the morphine also
responded to the MCR. Now we have clinically defined who the patients are, they
are the patients that have more anesthesia delarosa than they do their initial
diagnosis of TN.Once we decide if you are a patient or not we do a
neuropsychological batter of tests–sitting there for a whole day. I am not checking if
you are unbalanced mentally or not, just how your brain works and how or if the
stimulation modifies the way in which your brain works. A lot of people are sensitive
about the testing and doing more psychological testing may change somewhat.Pain
has two components–psychological and physical. It is very frustrating for many
doctors to treat pain patients.It is not something that you can wrap your brain
around or wrap your hand around. Now if there a tumor you can see the tumor and
can take it out. Doctors who are not neurosurgeons, neurologists, pain specialists
or psychiatrists find it very frustrating to treat pain patients or psychiatric patients.
There is not something to point to on a scan that shows there is the problem right
there. Pain situations do not work that way. Then patients get in the treadmill
situation where the doctors are saying,, ‘Well I don’t know." So now they ask for
more neuropsychological testing trying to figure out how much of this is in your mind
and not in your body. We try to insure the patients that we are just trying to look at
your attention and concentration.People hear deep brain stimulation and Motor
Cortex Stimulation (MCS) and they don’t know about it. I talk to Parkinson's groups
and groups like yours, and they don’t know–do you have to wear a big radar dish
on top of your head or something like that. Not at all. Besides doing the
neuropsychological testing, we do a specialized MRI scan. It is called a functional
MRI, which means that the MRI is able to show differential distribution of blood flow
in the brain. And what we think, (not 100% sure) if there is an area of the brain
where the body seems to be shunting blood flow to, then that is a part of the brain
which is more active than other parts of the brain.What happens is that if I am
opening and closing my left hand or moving my left arm in the powerful MRI scanner
the area of my brain on the opposite side of my head, that correlates to closing my
left hand and moving my left arm and will light up on the MRI scanner.
This has been a very useful tool for neuroscientists to figure out and confirm that
certain parts of the brain do certain things.
So what we do with our patients that have continual pain, we look into areas of the
brain that are activated just to the baseline. What we do if someone with TN on the
left side of their face, and depending on which division, we have them open and
close their eyes. The first division we try to have them move their cheek, the second
division we have them move their tongue, to try to get a sense where on the brain
that motor activity will correlate. What that does for us is the ability to test it in the
operating room. I can directly stimulate those areas and if those areas correlate
perfectly then I can make a much small ‘hole’ in the skull which I replace with a little
trap door.The MRI that was taken allows me to navigate around the brain, I have
this little pointer with camera eyes with a screen with that patients MRI on it with this
camera and the little pointer I can navigate around their head. On the screen it
shows me where I am pointing. It is called frameless navigation of the brain. It
provides me the ability to say this is where they have most of their pain in their third
division of trigeminal nerve, and this is where they were moving their jaw and their
tongue and that is right here, so this is where I will make my incision and drill the
hole.
Now you have the functional MRI with the brain lab (the computer system with
screen, and wand etc.) Then you have the neuropsychological testing . Now it is
time to go to the operating room.
Everything is done on the opposite side of the body, which is the way it was
designed, for what ever reason. During the operation you are asleep. When you
are awake it is difficult for the patient and difficult for the doctor (me). In order to use
the brain lab, I have to put your head in a head holder that holds the head still.
A lot of surgeries I do for epilepsy the patient is awake. We have to sedate the
patient a bit and give them novocaine.
I put the Novocain at the spots where the pins go that hold the head in place.
I found no benefits to keeping patients awake when operating and in probing the
brain. I put everyone under general anesthesia, we put them to sleep, then put
them in a head holder. I shave a small amount of hair, just enough to make a small
incision, drill a little whole, put it on the table and then bolt back it in when we are
done.
The good news is that like those patients who have had a MVD you absolutely have
to see the brain to get to the brain stem where we perform the MVD. In order to do
that we must cut something called the dura mater, a leather like covering that
protects the brain. For most things when we do brain surgery, we have to open the
dura mater. When we are finished, we sow it back together, it heals when we are
done.
The good news is that we don’t always have to open up the dura when we do MCS
we can place the stimulator directly on the dura surface. This adds more protection
for the brain. I never have to see the brain in a majority of patients. The stimulation
can go through the dura which covers the brain right on to the brain surface.That
was a problem because the energy had to be so high to get through the dura that
the batter would wear out quickly. The good news is, we have rechargeable
batteries. So even though you must have very high stimulation energy being used
by the battery it can be recharged. The batteries last for about nine years.
If we do not have to open the dura, what we do? I take a stimulator that has four
little contacts on it attached to a wire. We take the brain lab with that little wand
enables me to say this is where the functional MRI told us which part of the face to
start with. So I just lay the stimulator on the dura or if I have to slide it just under the
dura and lay it on the brain and there are four little contacts on the stimulator. Then
we stimulate and test to see if we can get that part of the face or if it is someone
with arm pain to move. We have fine little needle like electrodes called EMG’s. And
that gives us a very fine image on the computer screen that shows if the muscle is
moving. Little tiny movement that we can see with the small needles. We don’t need
to see big movements, just little fine movements. Then we may have to move the
stimulator a little lower or higher.When we have the stimulator over the exact area
where the patients pain was, I sew it in place. I don’t sew it to the brain, I sew it to
the dura. I then tunnel the wire under the skin and bring it out in the neck. Then I
connect the wire to an external hand held battery. You and I have a programmer. I
program a couple of things in that I am familiar with, and we allow the patient some
way of slightly increasing the power up or down.If I open the dura you spend the
night in intensive care unit. If I don’t open the dura you spend the night in the
intermediate care unit. Being totally attached to the stimulator.It is a pretty easy
operation. Usually walking around the evening of the surgery. The apparatus is
stimulating the brain, while we are doing pain measurements, during the a.m., p.m.,
and evening. Based on where the stimulation primers are. I almost always do the
first part of the operation on a Monday. There are two parts to the operation.
By the middle of the week we make a assessment as to whether or not it is working.
The placebo effect is quite high, because people WANT it to work. Many see it as
their last chance for help! Remember, it is never your last chance. There is always
something coming over the horizon in either medicine or a new device. This does
offer new hope for people, but it is not a last resort.
The MCS does not always work. But what I hope is that it will be a different
sensation. I still have burning pain, but I have something else, maybe a tingling, I
still have pain but it is not the same characteristics as before. I don’t like it but it is
somewhat different. We can determine after three or four days that the pain has
some different qualities to itSome people the pain decreases by twenty percent or
more.
If that is the case then on Friday or Monday we can decide what we are going to do.
One of two things happens. If they don’t think it is working, they don’t have any new
or different sensations on their face then we go back into the operating room and
take the device out. Then wait for the next type of device that comes up.If
something good happens, instead of taking it out, we put you to sleep again and I
open the incision and internalize the device, that means taking out the outside
connecting wire and discard that. Then I look for the good clean wire that we left in
the area and put in the battery. It is kind of a large battery, that can be put in the
chest area where it is easy to get to and it is safer that other areas of the body. We
make a pocket that will fit the battery run the wire underneath the skin to the pocket,
we connect the device and put the battery in the pocket. We sew it up with the
stitches underneath the skin so it will look nice. Then we are done.
The whole device is internalized, you do not see it. This device does not interfere
with pacemakers. When you are programming you pain device, it sometimes can
turn the pacemaker off. They can sit right next to each other with no problems. But
programming it can turn the pacemaker off.
This device is not approved for TN by the FDA, but for spinal cord stimulation.
There are so few patients that get this device, there is no incentive for the drug
company to go through the entire approval process. It works and all the parts and
equipment are well suited for the problems that we have been talking about.
The patients with TN that I have installed the device are doing extremely good. Two
or three of the patients it has been life changing for them. They feel that their pain
is almost completely gone. Fifty percent of all patients report some relief. We at
UCSD, have seen 100% of our patients get some relief. 50% of the patients say
they have gotten at least a 50% reduction of pain.
I have only been doing this procedure for about a year. We are now at the stage
where we would like to use this to slow down the use of medication for pain relief.
This would reduce that doped up, sleepy, off balance feeling. Slowly reduce the
medication until it is not needed any more or a greatly reduced dose.
One of our patients has hat TN for over 40 years, she has had two MVD’s. The last
one the accidentally cut the nervewhich resulted in anesthesia delarosa. After the
MCS (motor cortex stimulation), she is almost pain free.
The thing I want to impress upon you that the MCS gets better with time. The
reduction of pain gets better over time! It is a mild progression over months that we
know of. We don’t know at the end of a year or three. We will keep you informed as
a year, two, and threes years goes by.It isn’t something that comes and goes, the
device is on ALL the time. When you turn it off the ‘pain’ comes back.If you turn it off
for a length of time and there is no pain, then when it comes back, it will probably
take a couple of months to get the pain back under control.
Return to Archives
Radiology, UCSD Medical Center, Division of Neurosurgery
Ph. 619-543-5540
Recap of December meeting 2005By Don Jeffries
Motor Cortex Stimulation (MCS)Dr. Buchanan may be the only neurosurgeon and
psychiatrist in the world! Dr. Buchanan is the pain neurosurgeon at the Medical
Center. I do all the operations for all the different pain syndromes along with the
microvascular decompression surgery the same as Dr. Alksne. By the way, Dr.
Alksne assisted Dr. Jannetta doing the first MVD ever done in the united states.
We have this new procedure call Motor Cortex Stimulation. (MCS)We will be doing a
kind of show and tell, rather than a slide show or a power point presentation. We will
be looking at things from a three dimensional point of view.
Motor means movement. One would think that it is counter intuitive, that doesn’t
make much sense to stimulate a part of the brain that controls movement. It would
be better to stimulate an area of the brain that has something to do with sensation.
That was tried, and when that part of the brain was stimulated that dealt with
sensation when it was stimulated with electricity, what happens is that people just
get an unusual feeling. It can also have a worsening of pain syndromes.With the
motor cortex stimulation (MCS), you can imagine if you stimulate an area of the
brain that causes one–half of your body to move, that one half of your body should
move, and indeed that is the case. If the stimulation energy is high enough and you
can make it high enough, that is part of the process of figuring out the best
parameters and numbers are and getting the patient up to the point where their
face of their arm will move depending where they have their pain. (Face, leg back
etc.) We get the arm or leg to move and then we slowly bring down the stimulation
intensity below the movement threshold or the motor threshold, that is where the
best pain relief is found, just below the movement threshold.How does it work? No
body really knows exactly how it works. The brain is not perfectly percolated Or
compartmentalized as one would imagine. There is not just one area of the brain
the deals with movement. The part of the brain that deals with movement also has
connections that deals the interpretation of movement. Also, what it feels like to
move, so the thought is that that area of the brain is highly connect with other areas
of the brain that have an affect on sensation. That is how Motor Cortex Stimulation
(MCS) came about.
There are only a few doctors that do this, we call ourselves functional
neurosurgeons. I do the surgery’s for epilepsy,for movement disorders usually
dealing with Parkinson’s, psychiatric disease, and for pain syndrome.Motor Cortex
Stimulation (MCS) is useful for many pain syndromes which includes TN. When
people have strokes, part of the brain dies because of a lack of blood and oxygen.
A part of the brain dies, usually in the tipper parts of the brain. That which dies is
inside the brain, that structure of the brain that is the great gate keeper of all
sensation. Everything that we experience in the environment comes through this
structure in the brain, called the thalamus. If you have a stroke in the thalamus you
can have really bad pain syndromes. Where as a rule these patients have
anesthesia delarosa, which can affect the entire one side of the body. As you can
imagine it is really debilitating. You have the pain on the side of your face, if you
can imagine the whole side of your body hurting like that all the time?
Who gets Motor Cortex Stimulation?
We generally do not do MCS on patients who have TN. It doesn’t seem to help
patients with Denovo "new TN."So that lancinating, sharp, stabbing, electrical like
pain isn’t really helped by MCS. It is patients who have had other things done and
have had that part of TN helped with the stabbing pain that this procedure may
help. Most of the pain can be gone, but often times you can be left with anesthesia
delarosa which is that condition that you do not have any sensation except pain,
burning pain and it is usually a chronic burning, throbbing pain. So those are the
patients that we can operate on as well as other patients with ‘atypical’ facial pain.
We would look at them for a possible implantation device.I have operated on 15
patients so far for the Motor Cortex implantation device. This is about as large a
series as any other place in the world. It is a relative new procedure. Initially it was
thought that this procedure was for the patients who had the strokes in the
thalamus.
But as it turns out from my own experience a UCSD it is the patients with failed
procedures of TN syndrome are responding best to the MCS procedure. Every
patient that we have implanted has experienced some relief from the pain.
We had one patient that said that the device was not responding real well that she
was still in pain. Although, during her visit we turned it off, and did not tell her that
we had turned it off. The MCS can be regulated by the doctor. It can be turned up,
down, or off. The patient does not know what you have done, they cannot tell if is
on or off, unless they feel the pain, then you turn it on, if the pain subsides, you
know it is working. If it doesn’t, you turn it up.As I said I had turned hers off. The next
day she called to say I must have turned it off because she was feeling pain. The
device did not cure her pain, but it cut it considerably.
I don’t really know how it is working. What we have found in a few patients is really
quite interesting. We are studying this because the area of the brain that this goes
on, where the motor cortex sits, is in what we refer to as in the frontal lobe. The
frontal lobe is what makes us who we are. It is where our personalities sit, our ability
to navigate through problems. Another thing that sits in the frontal lobe is our ability
to draw our attentions to things. It allows us to concentrate enough to not be
distracted by many things, that you are able to maintain your attention on the task.
The patients with frontal lobe damage through stroke, damage, or trauma has a
very difficult time concentrating, and maintaining their concentration and attention
on a task. And being a neurosurgeon/psychiatrist the issue that I am finding in the
patients is that: We have an individual whom I operated on who had a thalamic
stroke. He come in with is wife; he has lost weight, he has grandchildren etc.. His
problem was on the left side of his body. We tried to treat his left arm because, he
would never drive with his left arm, wouldn’t pick up his grand kids with his left arm
etc.. His wife said,"he is picking up his grand children with his left arm, he is driving
with both arms. But, if I ask him how is the pain in your hand and arm? He will look at
it and say it is still burning I can still feel the burning in my arm and my hand. I don’t
think it is a ten any more, but I think it is seven or an eight. Yet his whole life has
changed.What I am wondering is that it seems one’s attention to the pain is being
disrupted. The individual does not notice it unless you draw their attention to it. I
have not found this so much with facial pain patients. I have found this more with the
thalamic stroke patients and that may make sense for the reason that there is 10
billion nerve cells and each one of those nerve cells can make 10-20,000
connections.The facial patients can pretty well tell you that the pain is gone or has
subsided. The stroke patients are just distracted from the pain.
This procedure is only done in about twenty-five centers in the country.
How do I assess for Motor Cortex Stimulation?There are ways in the past that were
used to assess. They were found to be just as necessary today. Where patients
were given IV morphine or a barbiturate. As you know in a time of pain morphine is
not very helpful. Then they would give them the barbiturate IV, and this kind of pain
tends to respond to barbiturates for a short period of time. This was the initial test
they used. Patients that responded to the barbiturate and not the morphine also
responded to the MCR. Now we have clinically defined who the patients are, they
are the patients that have more anesthesia delarosa than they do their initial
diagnosis of TN.Once we decide if you are a patient or not we do a
neuropsychological batter of tests–sitting there for a whole day. I am not checking if
you are unbalanced mentally or not, just how your brain works and how or if the
stimulation modifies the way in which your brain works. A lot of people are sensitive
about the testing and doing more psychological testing may change somewhat.Pain
has two components–psychological and physical. It is very frustrating for many
doctors to treat pain patients.It is not something that you can wrap your brain
around or wrap your hand around. Now if there a tumor you can see the tumor and
can take it out. Doctors who are not neurosurgeons, neurologists, pain specialists
or psychiatrists find it very frustrating to treat pain patients or psychiatric patients.
There is not something to point to on a scan that shows there is the problem right
there. Pain situations do not work that way. Then patients get in the treadmill
situation where the doctors are saying,, ‘Well I don’t know." So now they ask for
more neuropsychological testing trying to figure out how much of this is in your mind
and not in your body. We try to insure the patients that we are just trying to look at
your attention and concentration.People hear deep brain stimulation and Motor
Cortex Stimulation (MCS) and they don’t know about it. I talk to Parkinson's groups
and groups like yours, and they don’t know–do you have to wear a big radar dish
on top of your head or something like that. Not at all. Besides doing the
neuropsychological testing, we do a specialized MRI scan. It is called a functional
MRI, which means that the MRI is able to show differential distribution of blood flow
in the brain. And what we think, (not 100% sure) if there is an area of the brain
where the body seems to be shunting blood flow to, then that is a part of the brain
which is more active than other parts of the brain.What happens is that if I am
opening and closing my left hand or moving my left arm in the powerful MRI scanner
the area of my brain on the opposite side of my head, that correlates to closing my
left hand and moving my left arm and will light up on the MRI scanner.
This has been a very useful tool for neuroscientists to figure out and confirm that
certain parts of the brain do certain things.
So what we do with our patients that have continual pain, we look into areas of the
brain that are activated just to the baseline. What we do if someone with TN on the
left side of their face, and depending on which division, we have them open and
close their eyes. The first division we try to have them move their cheek, the second
division we have them move their tongue, to try to get a sense where on the brain
that motor activity will correlate. What that does for us is the ability to test it in the
operating room. I can directly stimulate those areas and if those areas correlate
perfectly then I can make a much small ‘hole’ in the skull which I replace with a little
trap door.The MRI that was taken allows me to navigate around the brain, I have
this little pointer with camera eyes with a screen with that patients MRI on it with this
camera and the little pointer I can navigate around their head. On the screen it
shows me where I am pointing. It is called frameless navigation of the brain. It
provides me the ability to say this is where they have most of their pain in their third
division of trigeminal nerve, and this is where they were moving their jaw and their
tongue and that is right here, so this is where I will make my incision and drill the
hole.
Now you have the functional MRI with the brain lab (the computer system with
screen, and wand etc.) Then you have the neuropsychological testing . Now it is
time to go to the operating room.
Everything is done on the opposite side of the body, which is the way it was
designed, for what ever reason. During the operation you are asleep. When you
are awake it is difficult for the patient and difficult for the doctor (me). In order to use
the brain lab, I have to put your head in a head holder that holds the head still.
A lot of surgeries I do for epilepsy the patient is awake. We have to sedate the
patient a bit and give them novocaine.
I put the Novocain at the spots where the pins go that hold the head in place.
I found no benefits to keeping patients awake when operating and in probing the
brain. I put everyone under general anesthesia, we put them to sleep, then put
them in a head holder. I shave a small amount of hair, just enough to make a small
incision, drill a little whole, put it on the table and then bolt back it in when we are
done.
The good news is that like those patients who have had a MVD you absolutely have
to see the brain to get to the brain stem where we perform the MVD. In order to do
that we must cut something called the dura mater, a leather like covering that
protects the brain. For most things when we do brain surgery, we have to open the
dura mater. When we are finished, we sow it back together, it heals when we are
done.
The good news is that we don’t always have to open up the dura when we do MCS
we can place the stimulator directly on the dura surface. This adds more protection
for the brain. I never have to see the brain in a majority of patients. The stimulation
can go through the dura which covers the brain right on to the brain surface.That
was a problem because the energy had to be so high to get through the dura that
the batter would wear out quickly. The good news is, we have rechargeable
batteries. So even though you must have very high stimulation energy being used
by the battery it can be recharged. The batteries last for about nine years.
If we do not have to open the dura, what we do? I take a stimulator that has four
little contacts on it attached to a wire. We take the brain lab with that little wand
enables me to say this is where the functional MRI told us which part of the face to
start with. So I just lay the stimulator on the dura or if I have to slide it just under the
dura and lay it on the brain and there are four little contacts on the stimulator. Then
we stimulate and test to see if we can get that part of the face or if it is someone
with arm pain to move. We have fine little needle like electrodes called EMG’s. And
that gives us a very fine image on the computer screen that shows if the muscle is
moving. Little tiny movement that we can see with the small needles. We don’t need
to see big movements, just little fine movements. Then we may have to move the
stimulator a little lower or higher.When we have the stimulator over the exact area
where the patients pain was, I sew it in place. I don’t sew it to the brain, I sew it to
the dura. I then tunnel the wire under the skin and bring it out in the neck. Then I
connect the wire to an external hand held battery. You and I have a programmer. I
program a couple of things in that I am familiar with, and we allow the patient some
way of slightly increasing the power up or down.If I open the dura you spend the
night in intensive care unit. If I don’t open the dura you spend the night in the
intermediate care unit. Being totally attached to the stimulator.It is a pretty easy
operation. Usually walking around the evening of the surgery. The apparatus is
stimulating the brain, while we are doing pain measurements, during the a.m., p.m.,
and evening. Based on where the stimulation primers are. I almost always do the
first part of the operation on a Monday. There are two parts to the operation.
By the middle of the week we make a assessment as to whether or not it is working.
The placebo effect is quite high, because people WANT it to work. Many see it as
their last chance for help! Remember, it is never your last chance. There is always
something coming over the horizon in either medicine or a new device. This does
offer new hope for people, but it is not a last resort.
The MCS does not always work. But what I hope is that it will be a different
sensation. I still have burning pain, but I have something else, maybe a tingling, I
still have pain but it is not the same characteristics as before. I don’t like it but it is
somewhat different. We can determine after three or four days that the pain has
some different qualities to itSome people the pain decreases by twenty percent or
more.
If that is the case then on Friday or Monday we can decide what we are going to do.
One of two things happens. If they don’t think it is working, they don’t have any new
or different sensations on their face then we go back into the operating room and
take the device out. Then wait for the next type of device that comes up.If
something good happens, instead of taking it out, we put you to sleep again and I
open the incision and internalize the device, that means taking out the outside
connecting wire and discard that. Then I look for the good clean wire that we left in
the area and put in the battery. It is kind of a large battery, that can be put in the
chest area where it is easy to get to and it is safer that other areas of the body. We
make a pocket that will fit the battery run the wire underneath the skin to the pocket,
we connect the device and put the battery in the pocket. We sew it up with the
stitches underneath the skin so it will look nice. Then we are done.
The whole device is internalized, you do not see it. This device does not interfere
with pacemakers. When you are programming you pain device, it sometimes can
turn the pacemaker off. They can sit right next to each other with no problems. But
programming it can turn the pacemaker off.
This device is not approved for TN by the FDA, but for spinal cord stimulation.
There are so few patients that get this device, there is no incentive for the drug
company to go through the entire approval process. It works and all the parts and
equipment are well suited for the problems that we have been talking about.
The patients with TN that I have installed the device are doing extremely good. Two
or three of the patients it has been life changing for them. They feel that their pain
is almost completely gone. Fifty percent of all patients report some relief. We at
UCSD, have seen 100% of our patients get some relief. 50% of the patients say
they have gotten at least a 50% reduction of pain.
I have only been doing this procedure for about a year. We are now at the stage
where we would like to use this to slow down the use of medication for pain relief.
This would reduce that doped up, sleepy, off balance feeling. Slowly reduce the
medication until it is not needed any more or a greatly reduced dose.
One of our patients has hat TN for over 40 years, she has had two MVD’s. The last
one the accidentally cut the nervewhich resulted in anesthesia delarosa. After the
MCS (motor cortex stimulation), she is almost pain free.
The thing I want to impress upon you that the MCS gets better with time. The
reduction of pain gets better over time! It is a mild progression over months that we
know of. We don’t know at the end of a year or three. We will keep you informed as
a year, two, and threes years goes by.It isn’t something that comes and goes, the
device is on ALL the time. When you turn it off the ‘pain’ comes back.If you turn it off
for a length of time and there is no pain, then when it comes back, it will probably
take a couple of months to get the pain back under control.
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