- [Voiceover] After you start to recognize
that someone might be having a stroke, right,
maybe they have some of the symptoms
we know to be common stroke symptoms,
like maybe one side of their face starts to droop.
Or maybe all of a sudden they have some vision loss
or some numbness or weakness on one side of their body.
Then you want to make sure that this person
gets to the hospital as quickly as possible
because remember more than any organ in the body,
our brains love oxygen.
Brain tissue cannot live without it even for a few minutes,
so in a stroke when blood stops flowing
to a part of the brain
and thus deprives the brain of the oxygen it carries,
the brain tissue that's missing out on oxygen
starts to die off.
So super important that whoever you're suspecting
of having a stroke is taken to the hospital
as quick as possible to save as much brain as possible.
So now that we're at the hospital,
what goes on there, what's gonna happen?
A few things are gonna happen.
I mean the plan is to diagnose the stroke, right,
with some tests and some imaging,
and then to treat the stroke with some medications.
So let's take a look.
We know that part of diagnosis includes a physical exam
to look for any physical signs
that the person has had a stroke.
Really importantly, it also includes imaging
like CT and MRI scans.
It includes lab tests, blood work to look for
an underlying cause of the stroke
or to rule out other diagnoses
like hypoglycemia, which can look like a stroke.
The kind of treatment that the person gets
really depends on the type of stroke that they had.
Let me show you what I mean here.
You could've had an ischemic stroke, for example,
where a clot blocks off a bit of blood vessel in the brain
and causes a stroke that way.
Or you could've had a hemorrhagic stroke, for example,
where a weakened blood vessel in the brain starts to leak,
maybe because of a ruptured aneurysm
or some trauma to the head,
like from a fall or something unpleasant like that.
But how does the type of stroke
you have influence treatment?
Because for ischemic strokes,
which you can usually identify on imaging,
actually let me clarify that.
You won't be able to see any brain changes on CT scan
right after a patient's had an ischemic stroke.
That's why this CT up here looks pretty normal.
But the key is that it doesn't look like
a hemorrhagic stroke CT scan,
which I'll show you in a few minutes.
So the patient in whom you're suspecting an ischemic stroke
gets certain medications that you
definitely do not get in hemorrhagic stroke.
Let me show you what I mean here.
Let me bring up a blood vessel here
to just show you how these medications work.
If the patient had an ischemic stroke
and came to the hospital quickly enough,
they'd often be given two types of medication.
One is aspirin, and aspirin doesn't actually do anything
about the existing clot.
It can't break it up or anything like that,
but what it can do, what it can do
is prevent new clots from forming.
So it stops platelets in your blood from working properly
because platelets in your blood are responsible
for forming the initial component of a blood clot.
It stops those from forming.
Really importantly, you might be given a type of medication
called a thrombolytic.
This thrombolytic is the one that can potentially
break up that clot that's causing the stroke, right?
You might have heard of clot-busting medication
and this would be type of that.
Thrombo means clot and lytic means to break something up.
This one in particular is called
tissue plasiminogen activator or TPA.
That sounds like a pretty confusing name
but it's called tissue plasminogen activator
because of what it does.
It activates a compound called plasminogen
that's already naturally found floating around in your blood
as part of the body's natural mechanism
to break up any clots that shouldn't be hanging around.
So TPA sort of kick starts this natural system
already in your bloodstream to try to bust up
the clot that causes the stroke, right?
Actually when plasminogen gets activated by TPA,
it turns into this compound called plasmin
and that's what's actually doing the busting up,
the clot busting, that's why I wrote plasmin here.
Really importantly about this drug,
the benefit of TPA is the highest
right after the stroke has occurred,
and then it just kinda gets
less and less effective from there.
Again, I'm just trying to highlight the fact
that the earlier the patient gets to the hospital,
the better the outcome,
the better the TPA will work.
That's ischemic strokes.
That's acute management of an ischemic stroke.
With hemorrhagic strokes though it's a different story
because when you have vessels that are bleeding out,
the first thing you want is for it
to clot off and stop bleeding,
and therefore the last thing you want is
to activate your plasminogen clot-busting system.
You won't be given TPA
because if you are given TPA,
then your blood will be far less likely to clot, right,
as we saw earlier.
Blood will just continue to pour out
of this deficiency in the blood vessel here, see?
Actually let me bring up a CT scan
of a hemorrhagic stroke.
You remember I said I was gonna bring one up.
You can see all of this blood here.
This bright spot is a big collection of blood
that's been sort of leaking out of blood vessels
in the brain that have ruptured.
You can see that this looks really different
from the CT scan over here on the left
of an ischemic stroke.
This is why brain scanning is super important
when you're diagnosing a stroke
'cause it really has big implications
on how you treat the stroke afterward.
For hemorrhagic strokes the focus of initial treatment
has to be a little different than with ischemic strokes.
For example, with hemorrhagic strokes
it's really important to find out
which blood vessel's bleeding,
so where exactly in the brain the bleed is.
That can be done by the imaging tests like CT
or MRI or angiography that we talked about.
Because the goal is to stop the bleed,
it's important to first know where it is.
Another thing, anytime you're bleeding
from a vessel, right, losing blood,
your heart starts to get a little worried, right?
Good ol' heart always looking out for you.
It starts to pump blood out a little harder
and it's thinking that that's what it'll take
to get blood going everywhere again.
Now your blood pressure's gone up.
But there's two main drawbacks to that.
One is that if a little clot has started to form, right,
to seal up the initial tear in the blood vessel,
is that new maybe not so stable clot
gets hit with blood racing along at high pressure,
it might get dislodged and rebleeding might happen.
The second drawback to blood pressure that gets too high is,
let's say that a clot hasn't formed
and it's still bleeding, it's still active.
Then now blood'll just start coming out
of the vessel even faster, right,
and that's probably the last thing that we want.
The patient might be given antihypertensives
or blood pressure lowering drugs
to try to keep the blood pressure from getting too high.
It's also really important with hemorrhagic strokes
that the healthcare team stops or reverses the effects
of any medication that the patient's regularly taking
that might increase bleeding,
such as warfarin or the aspirin that we mentioned earlier.
Also really important is that pressure building up
in the brain and the skull
from all this blood is controlled.
For starters one simple way to do that is to just make sure
that the head of the patient's bed is elevated.
This works just because of good ol' gravity.
When the patient's head is elevated,
then more blood will flow out of the head
in the jugular veins, right?
That's one way of lowering pressure in the head a bit.
One reason why keeping pressure in the head
at a normal-ish level is really important is that
when your brain starts to get pushed on or compressed,
it kinda disrupts the normal electrical activity
in the brain and you could end up having a seizure.
So the doctors might consider giving an anticonvulsant,
which is a medication to prevent seizures from happening.
Another reason is just because
some pretty vital areas in your brain,
particularly your brain stem,
they might get compressed
with all of this pressure building up
and that's pretty quickly fatal so we don't want that.
There are some other surgical ways
to keep pressure under control
but we won't focus on that right now.
But you can definitely start to see
that management of hemorrhagic stroke
is really about managing the patient
until interventions like surgery can happen.
Whereas with ischemic strokes,
while you might still need
more invasive treatment down the line,
at least you can give TPA initially
to try to get things resolved beforehand,
try to bust up that clot
before you need more invasive treatment.
So that's a quick look at
some of the immediate management
of ischemic and hemorrhagic strokes.