> Can anyone tell me whether an invasive EEG is painful and how long it will
>
> last? I was told by my specialist that I might have to go for an invasive
> EEG because my long term video EEG didn't show anything.
Hi,
Though it is a little bit technical, here is an excellent document that
describe how it "actually" works.
http://www-vf.bio.uu.nl/lab/NE/scripties/Building_a_Brain_Interface.pdf
In more human language, it comes down to the following.
The invasive or the depth EEG test requires implanting electrodes
temporarily into the brain. Obviously, the head must be absolutely still
during this procedure. Your head will be placed in a frame that is pinned to
your skull. CT or MRI scanning will then help the doctor decide where the
electrodes should be placed. With great care and precision, the neurosurgeon
drills through the skull, so this will cause you no pain, but some people
experience discomfort despite the use of local anesthesia. After the
operation, you'll probably have a nasty headache. Your head will be wrapped
in a bandage, and your scalp will be sore. It will take about a month to
heal after the procedure is done. Depth electrodes, also called subdural
electrodes, are generally not used in those areas of the brain that affect
speech or movement, to avoid causing damage. Once the depth electrodes are
in place, EEG information is collected directly, a process called
electrocorticrography. If a single focus is found, the next step may be
surgery to remove it. Otherwise only the electrodes themselves are removed.
Note that there are some other "invasive" tests as well; e.g. subdural grid
EEG test. Your neuro should be able to tell you more about it, what these
test actually mean for you and how you should prepare for it.
Take care.

Signature
Thanks.
Marco
The Netherlands
Dave ???? - 27 Dec 2004 23:45 GMT
Howdy!
My Long Term Monitoring was also inconclusive and I had to have Invasive
Monitoring. As for "painful"... see the last paragraph!
Here's a little something that I wrote quite some time ago:
===========================
I was admitted into Strong Memorial Hospital in Rochester, NY for Invasive
Monitoring by the Comprehensive Epilepsy Program at noon on Sunday Sept. 18,
1994. I was scheduled for surgery with Dr. W. Pilcher at 7:30 am on Monday,
Sept. 19. Dr Pilcher is the CEP Neurosurgeon. I was expecting to get my hair
cut an noon as I was admitted into the 3600 Wing on the 5th Floor but this
did not happen. Apparently there is no set time for the ritualistic shaving
and it can happen at any time; from the time that you are admitted until
just before the anesthesiologist puts you under. In my case, my neurosurgeon
came in and shaved me just before I was taken down to surgery.
The kind of invasive monitoring that I had done was to have three 2" teflon
strips inserted over each temporal lobe. Each teflon strip contains 3
electrodes. The first step was to make a vertical 2" incision at each temple
approximately 1" in front of each ear channel. They then peeled the scalp
away from the skull just like you would use a knife to cut a soft boiled egg
free from it's shell. They then drilled two holes in the skull 1.2 cm in
diameter. One hole was drilled into each temple. Three strips were then
inserted into each hole and the connecting wires were run out of the holes
drilled into the skull. The wires were run from the holes in the skull to 3
holes made in the scalp about 2" above the ear and almost parallel with the
floor. The vertical incisions at the temple were then stapled shut. Much to
my surprise, they did not plug the holes that were drilled into the skull;
instead they just leave them alone and let nature take its course and
naturally plug the holes with scar tissue. Three additional wires with
electrodes were added to the outside of the scalp at the occipital lobe
area. Two of these electrodes were for comparison currents and the third was
a ground line. By using this method, which compares the difference in the
current between the two outside lines and each of the invasive monitors, a
much finer calibration can be used to compare the difference in the
electrical charge at each than could be obtained if calculations were made
which only used one charge. In my case the entire operation took 4 hours.
The next step was to take a C.T. Scan (also known as a C.A.T. Scan) and find
out exactly where each electrode was located. Recision is essential because
the precise location of many irregularities are determined by triangulation.
I must admit that I do not remember having a C.T. Scan taken after surgery.
My first recollection of self awareness occurred after I had been returned
to the recovery room following my C.T. Scan.
Once the electrodes have been inserted between the skull and the surface of
the brain, the procedure is exactly the same as Long Term Monitoring
(L.T.M.) after the electrodes have been connected to the scalp.
If you ever thought that you have had the worst headache that you could ever
have, let somebody drill some holes in your head; because, until you do, you
don't know what a REAL headache feels like! This pain, which is constant and
intense, lasts for 2 or 3 days and shifts around from your temporal lobes to
your occipital lobes.
===========================

Signature
Dave ????
http://www.howdydave.com
> > Can anyone tell me whether an invasive EEG is painful and how long it will
> >
[quoted text clipped - 30 lines]
>
> Take care.
Dave ???? - 28 Dec 2004 00:46 GMT
Howdy Again Massimo!
I should add that THIS WAS MY CASE!
I have seizure activities in BOTH temporal lobes. Maybe that's why I had 2
holes drilled and strips placed on both sides. Some folks may only need one
hole drilled, but I can't state that as a fact.

Signature
Dave ????
http://www.howdydave.com
> Howdy!
>
[quoted text clipped - 53 lines]
>
> ===========================
> Merry Christmas to everyone
>
[quoted text clipped - 3 lines]
>
> Well, I don't have to mention that I'm bit scared about this.
The brain itself doesn't have pain receptors. I think just about everything
else does though (bone, other tissues) although I think with blood vessels
there are fewer pain receptors than in other body tissues.
If there is loss of cerebral spinal fluid, there can be a headache from that
(same thing happens with a lumbar puncture or a spinal tap).
That's all I know.
Barb
> Thanks,
>
> Massimo,
> Switzerland