Let’s talk about
We call this a cingulate gyrus.
You’re going underneath the falx
cerebri to the opposite side.
What are you doing?
You are hurting or compressing the
branches of the anterior cerebral artery.
And my problem is going to be where?
Upper or lower
Let’s move on.
Transtentorial, where are you?
Medial temporal lobe.
And this is known as your uncus.
We call this transtentorial
or uncal herniation.
What is it doing?
This temporal lobe or herniation is then
going to cause compression of perhaps
the third cranial nerve.
That’s your oculomotor.
If you lose your parasympathetic,
what may happen to the pupil?
Because you lose the parasympathetic.
One more time,
what if the papillary
constriction is intact?
And you only have a motor
issue with oculomotor.
There must be infarction to that nerve.
I’ve mentioned that before,
I’m mentioning it now.
If you’re not familiar with it, please
make sure that you divide the oculomotor
into compression effects with pupillary
compromise or papillary functioning intact,
which would then refer
to your infarctions.
In addition, temporal lobe compressed
against the tentorium cerebelli.
There’s every possibility that you
not only have an uncal herniation,
but then at the same time, you could
have a tonsillary herniation.
What is your tonsil
referring to once again?
It’s the cerebellar tonsils that are
then herniating into the foramen magnum.
Compression of the medullary
Look for that.
That’s your tonsillar
One thing that I want to
bring to your attention
is that if there’s an uncal herniation
and you’re pressing upon that brain stem
and you’re pushing it downwards,
you might then cause stretching of the
vessels of the brain stem, aren’t you?
Stretching of the blood
vessels of the brain stem.
What if it ruptures?
What do you call this? What
kind of hemorrhage is this?
A Duret hemorrhage.
Beautiful story, isn’t it?
All under the premise of
increased intracranial pressure.
Simple measures make all the
difference in the world.
Raise the bed for 45 degrees, try
to drain the fluid conservatively.
And that is an answer choice.
No circumferential tape around the neck for
securing your ETT. Your endotracheal tube.
So that you dont increase your jugular venous pressure.
PCO2 normally should be at 40.
Hyperventilation will then cause
your blowing off your carbon dioxide
and it starts dropping below 40.
This could help with simple measures of
the decreasing intracranial pressure.
What does mannitol mean to you?
It’s a huge osmotic drug.
And this osmotic agent is going to do what?
Simple measures to decrease
It brings about drainage because it’s
an osmotic agent, is that clear?
Don’t worry about the
dosage so much right now.
Any one of these could be answer choices.
Use common sense.
Now, apart from that, you get
a little bit more invasive.
You want to be careful.
So mannitol did what?
It was an osmotic agent
that was pulling water out.
What kind of saline might
you want to use so that
you can have the same
type of effect please?
Greater than 0.9%, right?
Normal saline is 0.9%.
Maybe using 1, 2, or 3%.
A "bullet" 30 cc’s.
IV steroids if due to a tumor
and at some point maybe a catheter
or intraventricular type of drainage.
You go from simple measures
and you start getting
into what you need to do
so that you can drain some of these fluid
to decrease the intracranial pressure.
In the meantime though,
you’re always going to look for what
is the underlying cause in the skull,
the brain in the box, remember?
And what’s in that box?
You could have the brain itself.
You could have the blood.
You could have the CSF.
And anyone of those could result in
increased intracranial pressure.
In the meantime, you need to make sure that
you make the patient feel comfortable.
Otherwise, we got issues.