[MUSIC].
Okay.
So, what we focused on in this unit has been problems within the cranium.
And they all have they all feedback into intracranial pressure which is really key.
An intracranial pressure is, is key because of what we call mass effect.
And what that means is, lets consider our three compartments.
We have.
The left hemisphere, the right hemisphere.
So telencephalic left, telencephalic right, and then we have infratentorial.
And infratentorial, this down here we have the brain stem.
Up here we're talking about the forebrain.
Now if the pressure increases enough in any one
of these compartments, the, the effect is that it will start to push out.
So the mass effect is simply that this.
This increase in mass has to go somewhere, it's going to push in, in all directions.
It pushes against the skull, no luck there, the skull's not moving.
And so if it's going to start, if it builds up enough
it will push across these barriers, across these, the brain's bulkheads.
And now it will effect.
Whatever else it, it, impacts.
And in this case, this would be a sub, a,
a falcine herniation and this would be a tentorial herniation.
The, the mass effect, the impact of the mass
effect is, is an impact that all of these.
Problems have share in common.
So a stroke, which is in the parenchyma of the brain and
intracranial bleed, which is a bleed somewhere
between the skull and the
the The, the brain, a traumatic brain injury.
This is happening, unfortunately, more and more as
we continue to fight wars with fancier weapons.
People get shrapnel that enters the, the brain.
People are in automobile accidents.
All these types of things concussions, head banging on the head,
all these various traumatic and/or penetrating injuries.
In addition this increase in pressure does not have to be due
to a stroke, it could be due to a growth, a brain tumor.
And even if that brain tumor is not
going to actually send a metastases off somewhere else.
and is therefore not malignant, it is very dangerous and can be lethal.
If it grows so big that it, it impairs brain function by increasing intracranial.
Pressure.
And finally, there's something that we
haven't talked much about, which is hydrocephalus.
In hydrocephalus, let's just look for a moment at the three compartments again.
There is an inner structure to these three compartments.
Wher, which is the ventricle system and the ventricles
contain CSF and they feed the.
The direction of flow for CSF is in this direction.
And then it goes and it fills this subarachnoid space, but if
this gets clogged up right here, which is where it usually does get clogged up, then
the, the CSF is being made but it can't flow out.
And now the.
The brain is going to blow up from the, from the inside.
Because this happens most commonly in babies.
The brain, the skull of the baby is, is, is
more forgiving than the skull of a of an adult.
And so, it might take awhile.
The, the baby might actually expand or swell for awhile before this becomes
symptomatic, because the pressure is so big that the brain is no longer working.
But in any case, eventually, hydrocephalus will increase intracranial pressure.
So, all of these things.
Increase intercranial pressure.
It is the major way in which all of these things negatively
impact brain function and lead to a great deal of
suffering and debilitation in people all over the world.
And from that not cheery note we'll conclude this week and we'll go
on to look at some things are working well and I very much hope that for all of you
that you don't encounter these in your lives.
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