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Current time:0:00Total duration:6:08

Ischemic and hemorrhagic strokes

Video transcript

you've probably heard of people having a stroke and you're probably familiar with with the notion that has something to do with the brain and you'd be right in particular it's a it's a rapid loss of brain function because of something strange happening in with the blood flow to the brain and let me show you that in a little bit more detail and to do that let's think about the two major types of stroke there's the ischemic strokes ischemic there are the ischemic strokes ischemic stroke and the other type of stroke is hemorrhagic and these can also be kind of sub categorized but I won't go into all of the details they're hemorrhagic hemorrhagic stroke and if I really just define ischemia and hemorrhaging to you I think you'll have an idea of how these strokes are different and how they interrupt the blood flow to different parts of the brain you know from the videos on stenosis and ischemia and the videos on heart attacks at ischemia is a lack of blood flow to certain to certain body tissues so in a scheme extra' leave Airi very similar to what we saw in a heart attack except it's not occurring in a coronary blood vessel it's occurring in a blood vessel in the brain so let me draw that right over here let's say that this is a blood vessel in the brain this right here is a blood vessel in the brain and let's say the blood is flowing in that direction this is an artery and so you can imagine that maybe there is a blood clot that forms in some part of the brain let me do the blood clot in magenta this blood clot might form because no that's not magenta the blood clot might form because maybe there's a plaque there maybe the plaque got ruptured either way this blood clot is restricting the flow of blood and we know that this blood clot we can call this a thrombus thrombus or we could say that thrombosis has occurred over here either way the blood flow is restricted and and the the brain tissue that's further downstream is not going to get its oxygen and it might die it might experience infarction and that's why ischemic strokes are also sometimes all cerebral infarction 'he's cerebral cerebral infarction 'he's these are all very fancy words but i think hopefully they're becoming a little bit more common in our vocabulary they keep showing up over and over again and i also want to be clear it's get most strokes are actually ischemic strokes that the numbers i looked up at they say 87% 87% of strokes are ischemic now the other type of way that you could have ischemia in one of these blood vessels and it's completely analogous to what we saw in in the heart when we saw had heart attacks is you could have thrombosis or you could also have an embolism whenever they have the whenever someone says thrombosis or thrombus or thrombi they're talking about blood clots whenever someone talks about an embolus or emboli or embolism they're talking about something moving through the blood that eventually blocks a blood vessel so you can actually have a thromboembolism you can actually have you can actually have a blood clot that gets broken off so instead of so you could actually so let me let me ignore this for an hour let me let me paint over it a little bit so that this isn't the main cause of blockage but you could actually have a blood clot that breaks off becomes a becomes an embolus it becomes an embolus and since it's an embolus due to a blood clot you call it thrombi thromboembolic I always have trouble saying all of these words and eventually it blocks it blocks a part of it blocks an artery right over here so this right here is an embolism embolism but either way you're blocking the blood flow further down the brain it could cause infarction that brain tissue will die and whatever that brain tissue did for for mental function or whatever is going to make it very hard for this person who's experiencing the stroke to do those things now it's not always noticeable that's called called a silent stroke but but damage is occurring the person experiencing the stroke and I'm not a doctor so take all of this with a grain of salt the person experiencing the stroke it could be anywhere from well one they might not even notice it even though damage is occurring they might have a headache or it might be more severe they might actually not be able to properly move a side of their body or side of their face or properly be able to speak so it really depends on what part of the brain is being damaged but in either of these situations an ischemic stroke is caused by some type of restriction or blockage that causes things downstream to not get proper oxygen and then so you can imagine cells over here are going to get their oxygen and that they might actually die a hemorrhagic stroke to hemorrhage literally means to bleed it's literally just a fancy word for bleeding and so in a hemorrhagic stroke you have a situation where a blood vessel can actually break where you have a blood vessel I'm trying to draw the same blood vessel where it actually breaks we can we'll talk more in the future of why a blood vessel might break strongly related to high blood pressure and other risk factors don't want to get into that right now but you could imagine if a blood vessel breaks you have all this blood spewing into a brain into the brain in kind of an uncontrolled way so let's say this little diagram I do here let's do that's part that part of the brain if you have a hemorrhagic stroke you have all this blood that's flowing into the brain and you could imagine all that uncontrolled blood will mess up that part of the brain it'll it'll cause those neurons and brain tissue to malfunction and maybe even cause some of it to die and it would also cause the blood flow further downstream to be impaired so it'll also the stuff downstream aren't going to get the blood they need because all of the blood is being released everywhere else and since 87 percent of strokes are ischemic strokes the remainder are hemorrhagic so this is the remaining or the remaining I should say the remaining 13% of strokes