- [voiceover] after you start to recognize that someone might behaving a stroke, right, maybe they have some of the symptoms we know to be common stroke symptoms, like maybe one side oftheir face starts to droop. or maybe all of a suddenthey have some vision loss or some numbness or weaknesson one side of their body. then you want to makesure that this person gets to the hospitalas quickly as possible
because remember more thanany organ in the body, our brains love oxygen. brain tissue cannot live withoutit even for a few minutes, so in a stroke when blood stops flowing to a part of the brain and thus deprives the brainof the oxygen it carries, the brain tissue that'smissing out on oxygen starts to die off. so super important thatwhoever you're suspecting
of having a stroke istaken to the hospital as quick as possible to saveas 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 todiagnose the stroke, right, with some tests and some imaging, and then to treat the strokewith some medications. so let's take a look.
we know that part of diagnosisincludes a physical exam to look for any physical signs that the person has had a stroke. really importantly, italso 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, whichcan look like a stroke.
the kind of treatment that the person gets really depends on the typeof stroke that they had. let me show you what i mean here. you could've had an ischemicstroke, for example, where a clot blocks off a bitof blood vessel in the brain and causes a stroke that way. or you could've had ahemorrhagic stroke, for example, where a weakened blood vesselin the brain starts to leak, maybe because of a ruptured aneurysm
or some trauma to the head, like from a fall or somethingunpleasant 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 seeany brain changes on ct scan right after a patient'shad an ischemic stroke.
that's why this ct uphere 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'resuspecting an ischemic stroke gets certain medications that you definitely do not getin hemorrhagic stroke. let me bring up a blood vessel here to just show you howthese medications work.
if the patient had an ischemic stroke and came to the hospital quickly enough, they'd often be giventwo types of medication. one is aspirin, and aspirindoesn't actually do anything about the existing clot. it can't break it upor anything like that, but what it can do, what it can do is prevent new clots from forming. so it stops platelets in yourblood from working properly
because platelets in yourblood are responsible for forming the initialcomponent of a blood clot. it stops those from forming. really importantly, you mightbe given a type of medication called a thrombolytic. this thrombolytic is theone that can potentially break up that clot that'scausing the stroke, right? you might have heard ofclot-busting medication and this would be type of that.
thrombo means clot and lyticmeans 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 tissueplasminogen activator because of what it does. it activates a compound called plasminogen that's already naturally foundfloating around in your blood as part of the body's natural mechanism
to break up any clots thatshouldn't be hanging around. so tpa sort of kickstarts this natural system already in your bloodstreamto try to bust up the clot that causes the stroke, right? actually when plasminogengets activated by tpa, it turns into this compound called plasmin and that's what's actuallydoing the busting up, the clot busting, that'swhy 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 tryingto highlight the fact that the earlier the patientgets to the hospital, the better the outcome, the better the tpa will work. that's ischemic strokes.
that's acute managementof an ischemic stroke. with hemorrhagic strokesthough it's a different story because when you have vesselsthat 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 plasminogenclot-busting system. you won't be given tpa because if you are given tpa,
then your blood will be farless likely to clot, right, as we saw earlier. blood will just continue to pour out of this deficiency in theblood vessel here, see? actually let me bring up a ct scan of a hemorrhagic stroke. you remember i said iwas gonna bring one up. you can see all of this blood here. this bright spot is abig collection of blood
that's been sort of leakingout of blood vessels in the brain that have ruptured. you can see that thislooks really different from the ct scan over here on the left of an ischemic stroke. this is why brain scanningis super important when you're diagnosing a stroke 'cause it really has big implications on how you treat the stroke afterward.
for hemorrhagic strokes thefocus of initial treatment has to be a little differentthan with ischemic strokes. for example, with hemorrhagic strokes it's really important to find out which blood vessel's bleeding, so where exactly inthe brain the bleed is. that can be done by theimaging tests like ct or mri or angiographythat 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 geta little worried, right? good ol' heart always looking out for you. it starts to pump bloodout a little harder and it's thinking thatthat'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 clothas started to form, right, to seal up the initialtear in the blood vessel, is that new maybe not so stable clot gets hit with blood racingalong at high pressure, it might get dislodged andrebleeding might happen. the second drawback to bloodpressure 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 thelast thing that we want. the patient might begiven antihypertensives or blood pressure lowering drugs to try to keep the bloodpressure from getting too high. it's also really importantwith hemorrhagic strokes that the healthcare teamstops or reverses the effects of any medication that thepatient's regularly taking
that might increase bleeding, such as warfarin or the aspirinthat we mentioned earlier. also really important isthat pressure building up in the brain and the skull from all this blood is controlled. for starters one simple way todo that is to just make sure that the head of thepatient's bed is elevated. this works just becauseof 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 loweringpressure in the head a bit. one reason why keepingpressure in the head at a normal-ish level isreally important is that when your brain starts toget pushed on or compressed, it kinda disrupts thenormal electrical activity in the brain and you couldend up having a seizure. so the doctors might considergiving an anticonvulsant,
which is a medication toprevent 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 quicklyfatal 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 interventionslike 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.
