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There are many causes for stroke and the causes can be sort of separated out based on the type of stroke that someone has. And I think it’s important because the vast majority of strokes are ischemic that we talked a little bit about the causes for ischemic strokes. And it’s worth it to recognize that sort of we had the risk factors that we talked about earlier, but this is actually the direct causes. And so for ischemic strokes, what we’re thinking about is and this is actually something that you’ll be experiencing if you’re ever in the hospital, how the physicians are approaching your evaluation because that the doctor is asking themselves, where did the stroke come from? And specifically there’s a clot that landed in an artery in the brain, where did that come from? And so the possibilities that we sort of consider are going to be one. And basically you can just start from here and you work your way up. Did it come from the heart? And we think about irregular heart rhythms that can occur and far and away the most common irregular heart rhythm in people over the age of 50 and the cause of probably close to 20% of all strokes is an irregular heart rhythm called A fib. Atrial fibrillation.
Other cardioembolic causes or embolic causes from the heart area would include a valvular disease if you have a mechanical valve. And so it’s interesting. There are two types of valves that are put into the heart. One is what’s called a bioprosthetic valve, which is usually from pigs, a porcine valve. Those aren’t much of a risk, but metal valves that the surgeon sometimes put in can be a high risk for forming blood clots in patients who have those types of middle valves are usual and very aggressive blood thinners like coumadin or Warfarin. Other areas that can cause stroke are also atherosclerosis of the aorta, if that’s very severe, that can actually break off and go into the brain. Then as we move up, we go into the neck and we look for causes of stroke in the neck. And one of the biggest causes we’d be carotid stenosis. The carotid arteries are on either side of the neck and basically you have four big pipes coming in to the neck. You have two arteries that come to the back. They’re called the vertebral arteries. They supply the back, the brainstem in the back of the brain. And then you’ve got the carotid arteries, which supply the anterior two thirds of your brain. And what can happen very frequently with diabetes, high blood pressure, high cholesterol, age, genetic predisposition, smoking, is that the carotid artery can start to become narrowed and it’s usually filled with cholesterol, plaque filled with cholesterol. And if that narrows to a point, and that’s usually something above 75% that can then become unstable, break off and go up into the brain causing stroke. In those types of scenarios, treatment often involves surgery and we can talk about that later.
Among some less common but important causes of stroke is something called a dissection. This is a type of or cause of stroke that is much more common in young people. Amongst the most common causes of stroke in young people, in fact. And a dissection is where the artery, and it could be any of the major arteries going up into the brain, gets injured or torn from trauma. And what happens is you can think of the arteries having multiple layers and there’s the outside layer and the inner layer. And what’ll happen is the inner layer from the trauma gets torn up and that exposes this basement that should never be exposed to blood and blood clots can form on that. And then the blood clots can go up into the brain and cause strokes. That’s an important thing to recognize. And again, this is something we see in young people often proceeded by trauma. And I can give you a good example of a patient I saw not too long ago who was a hockey player and was involved in an active hockey game the night before. Came home and often when you have a dissection, there’s some pain. and the next day had a stroke related to a torn artery. And we can talk about the treatment of that a little bit later, but it does involve more aggressive blood thinners for approximately three months.
So when it comes to a stroke, it’s important to recognize what the signs and symptoms of stroke are. But to understand that very well, it’s important to sort of recognize maybe some of the anatomy of the brain and anatomy, the blood vessels. And so the first thing to sort of realize is that your brain is sort of cut right down the middle and there’s blood flow on the right side of the brain and there’s blood flow in the left side of the brain. And because of that, the symptoms are very frequently lateralized. And so that’s actually an important part of how when I see somebody, if I’m thinking about stroke, how I evaluate them, I’m looking for these lateralized signs. And so the idea here is that if a blood clot were to travel up the carotid artery and, and land somewhere in the brain, say on the right side, while I could envision that the right side of the brain controls the left side of the body, so they can have numbness or weakness on the left side, they could have vision changes on the left side. And now on the flip side, if it were to come up the left side, it would affect the right side of the body.
Lastly in the back of the brain where you’ve got two separate arteries coming up with a back called the vertebral arteries, they supply the brainstem and an area of the brain called the Cerebellum, which is involved in coordination. And so with strokes that occur there, these can be much more difficult and actually much more dangerous. With respect to symptoms in that area, the cerebellum is involved in coordination. So if you want to pick up something, if I had a cup here and I wanted to pick it up, it takes all of these different muscles. My, my deltoid, my biceps, my triceps, all these muscles, it takes a plan so that they’re coordinating their movement and a nice smooth movement. And your cerebellum is what does that, when the cerebellum doesn’t work, that same nice, smooth movement would look something along the lines of this with each muscle overcompensating and over doing what it’s supposed to do. And so people can have balance issues and ability to stand. Walk. When the brainstems involved, other things can happen. Like you can develop vertigo, which is a sense of the room is spinning, double vision, sudden slurred speech. And these are all signs of brainstem strokes that can be quite dangerous. And again, I point out very difficult for the clinician or for the provider to sort of nail down because they’re hard to detect.
Another important thing to sort of recognize is that language and your brain is lateralized. In the vast majority of people language is on the left side of the brain. Sometimes it can be on the right side of the brain, but the vast majority is on the left. And so when a stroke involves the language area, it can be sometimes hard to recognize because it just seems like that person’s confused or acting strangely, they may not even have any weakness at all. But when languages is involved, we call that aphasia and people can have a few different issues. They can have a difficult time expressing words so people can, people can often say, I know what I want to say, but I can’t get the words out. That occurs when a stroke involves the inferior frontal lobe on the left side in the area of the brain called the Broca’s area or another area of language is in the back of the brain and the temporal lobe called Wernicke’s area. And when a stroke occurs there, people aren’t able to comprehend things so they can talk but it doesn’t make any sense. They will often sort of say word salad. They’ll say things that don’t make sense or it can be actually kind of tough. You know, you can walk into a room with somebody and you know, they’ll sort of read your body cues and say very simple nonspecific things that sound like it sort of makes sense. Like, hey, how you doing? But if you ask them very specific things like, can you show me two fingers? They can’t comprehend that and do it. So those can be dangerous and easy to miss.
The diagnosis of the stroke is confirmed typically on brain imaging. And so the two brain imaging modalities that we’ll use to confirm a stroke, preferably it’s MRI. MRI is generally speaking, the gold standard way to confirm it and there’s something called diffusion weighted imaging where we see sort of a bright white dot where the stroke is at. It is black and white. It’s very clear and that’s what we see. There are some people who can’t get MRIs because they have a metal in their body. MRI is a big magnet, or if they have a pacemaker. In those cases we use CT. CT is less sensitive, but frequently we do eventually see the stroke on the CT and what we see on CT is an area of low density where the stroke is at. There’s a little bit of swelling and more water in that part of the brain is it swells up when it’s injured and we can see that looks at less dense than the rest of the brain. With our current state of the art imaging techniques, specifically MRI, we can confirm the diagnosis of a stroke in someone who’s had one in well over 90% of cases.
We’ll get an MRI and an MRI, which is by far and away our most sensitive tool for detecting stroke. It comes in two parts. The first is the MR image itself, the MRI, and that’s going to show us the brain. And on that, that’s about a 30 to 45 minute test in a big tube. So you have to sit still to get a good picture. But keep in mind, MRIs are giant magnets, there’s no radiation exposure. And again, we can see a pinpoint size stroke that we would never see with any other tool. On top of that we can see new strokes and old strokes. So there are different, basically a stroke within the first 10 days looks different than a stroke that’s 30 days old, which looks different than a stroke that’s four years old. So we can actually sort of differentiate between different ages of strokes, often not perfectly, but to a large degree. Number two, the second part of the MRI, something called an MR Angiogram. And the idea here is that actually we’re looking at blood vessels of the brain. And actually blood vessels from the heart all the way up. And there’s a few different ways for us to do that. So the most common way here at Tucson Medical Center is with an MR Angiogram. There is something called a CT angiogram, and there’s also a carotid ultrasound and we’re all sort of trying to answer of similar questions with each test. With an MR Angiogram, you’re in the big tube and you’re just sitting still and you don’t have to do anything. The people who are doing the MRI can essentially adjust the MRI to, instead of looking at stationary tissue, they will look at moving things. So everything that’s moving gets picked up and the things that are stationary you can’t see. And so all of a sudden the arteries light up and you can see them very well.
Sometimes an MRI isn’t possible or for some reason the MRI is inadequate. So in those cases we’ll use something called a CT angiogram. A CT angiogram is where they actually inject dye into your arm and move you through a CT scan. A CT scan is again is that big donut. It’s very fast. It’s probably a two to five minute study and basically as they’re injecting the dye, they can see that dye move through your arteries and you move through that scanner as a dye moves through you. The last thing is something called the carotid ultrasound. The carotid ultrasound, you know you’ve got four pipes, so the carotid ultrasounds really sees the carotids very, very well. But the other arteries you don’t see as well. So the carotid ultrasound can sometimes be a little bit limited and something we use to augment the other studies that we’ve had done. Beyond that we’ll often be checking lab work, like I said earlier. So we’re checking cholesterol screens. Again, paying very careful attention to your total cholesterol, the bad cholesterol called an LDL. We can get your blood sugars and those are the main tests that we’re going to be ordering. The other things that sort of expect in the hospital, and these are actually very important parts of your hospitalization, are going to be rehab after someone has a stroke and they’ve got some deficits we know that sort of, my analogy is is that your brain is like the roots of a tree. Okay. If there’s an area of damage, your brain cells are like roots. There are around there. And what they’ll do is if you stimulate them, they’ll grow around that area that they can’t get water from anymore. They’ll grow around that injury and they’ll make up for it. But the key to doing that is early Rehab, early therapy, early exercise. So in the hospital, one of the most important things that we do is we get physical therapy, speech therapy, occupational therapy involved depending on someone’s deficits from the stroke, and then try to get them into some type of rehab situation where they can continue to improve afterwards. So in summary, when someone comes into the hospital, one expect things to move really fast because time is of the essence. Number two, you’re going to get a variety of scans all looking at sort of what’s the cause of the stroke? Looking at your heart, looking at the arteries, and really carefully looking at the brain. And lastly, but frankly, most importantly is going to be the rehab aspect of your treatment.
When someone has a stroke, I emphasize this, it is crucial to get into the hospital. Let’s talk about sort of what to expect once you’re in the hospital. The first thing I would point out is if someone’s having a stroke or you believe someone’s having a stroke, the best way to get someone into the hospital fast, and again, the crucial thing here is time is brain. Fast is important, is a calling nine one one and using the emergency medical services, they are trained paramedics and EMTs are trained to recognize stroke and they will get you in fast. Once you’re in the hospital, what should you expect to sort of have happen? The first thing is you come into the ER with a stroke. Usually, things are going to move very, very quickly and immediately, you’d have a blood draw done looking for any evidence of things that would provoke stroke, getting your cholesterol in your blood sugar, making sure that you’re not anemic. And then initially a cat scan is generally the most common first test done. A cat scan is not the most sensitive test for stroke, but it can be done fast and efficiently and it actually, while it’s not sensitive for ischemic stroke like we talked about before, it is actually very sensitive for hemorrhagic stroke and subarachnoid hemorrhage. After the CT scan is done and the blood work is done, often there’s going to be the decision as to whether or not someone should get clot buster. And that’s something that we’ll talk about later. That decision has to be made very, very rapidly. And then often the person who’s had the stroke is admitted to the hospital and will often stay for a day or two. During that hospital stay the question that the physician or the team is trying to sort of ask themselves is where did the stroke come from? And that’s a crucial question to ask ourselves because that is going to dictate how we prevent another one from ever occurring. And so that’ll involve basically evaluating you from here on up. They’ll be doing an EKG, looking at your heart rhythm, looking for A fib. They’ll often have you on continuous cardiac telemetry. Again, looking at the rhythm of the heart, looking for A fib or any other irregular heart rhythm that can provoke stroke. Often you will get an echocardiogram, and this is kind of like what they use, looking at an ultrasound, like what we use for pregnant women, but instead we can actually look at it through the sternum and look at the structure of the heart, looking at the heart function, looking at the valves of the heart.
An important thing to recognize are the signs and symptoms of stroke. It’s critical to know the signs and symptoms of stroke because if you can’t recognize it, you’re not going to get someone into the hospital. And time is brain. And getting someone into the hospital as soon as possible is crucial. A nice acronym to remember for the signs and symptoms of stroke, which can be a little complex, is something called B.E.F.A.S.T. And what does B.E.F.A.S.T. stand for? Balance. Eyes. So first of all, you look at someone’s balance. Are they able to walk a straight line eyes? Do they have any vision problems? Sudden vision loss in one eye or both eyes? F fast. F look at their face. Smile is their face symmetric and especially you’re looking at, interestingly with a stroke, the stroke involves the lower half of the face generally. Okay, so we’re not looking at the eyebrows and the eye movements, but we’re looking at the lower half of the face. And so we asked him to smile. And you’re looking at these folds on either side right here are the dimples. Nice and symmetric. If you’re still not convinced, you can sometimes even count the teeth across to see how symmetric it is. But usually it’s pretty obvious. Arm. Ask someone to lift out their arms straight out. And ideally what you’d do is have them hold their palms up and you’re looking for weakness. If they’re bringing their arm down or bring their arm across like this, that’s a sign of a stroke. And then speech, have them repeat a sentence. Can they say it clearly? Are they able to repeat the sentence? And then if they can’t do any of those things you want to look at the time. Again, I can’t emphasize this enough. Time is critical. Time is brain. And the reason is that the stroke treatments that we have available in the hospital, the only FDA approved treatments are time sensitive. Intravenous clot-buster is only available within the first three hours after a stroke. And sometimes we’ll give it longer, but the longer we wait, the less effective it is. So in recap, the signs and symptoms of a stroke can be nicely encapsulated in the acronym B.E.F.A.S.T. Balance, eyes, face, arm, speech. Look at the time.
So in summary, treatment for acute stroke, intravenous TPA and club buster, there is something called intraarterial treatment that can be given to a certain subset of patients that most stroke centers here in Tucson are able to provide. If we look at causes of stroke and prevention for those, it’s a strong anticoagulant for A fib, coumadin, Xarelto, Eliquis or Pradaxa. And then for the rest of stroke, we’re looking at aspirin, Plavix, or Agoronox, cholesterol control, and blood pressure control. For a certain subset of patients with carotid artery stenosis, some of them can be aggressively treated medically, but some of them will need some type of definitive treatment to open up that narrowing. And that’s either carotid endarterectomy with a vascular surgeon or carotid stenting.
For treatment of an acute stroke, a stroke that has just happened, there is one drug that’s been FDA approved called TPA or tissue plasminogen activator. That’s a drug that right now it can only be given in the hospital and this is the reason that we want people to get into the hospital fast. On top of that, it can only be given really within the first four and a half hours after stroke onset, I would back up and point out that it’s been FDA approved to three hours, but most hospitals recognize an advisory from the American Heart and Stroke Association that have recommended that we give it up to four and a half hours in very select patients. And so because of this, it’s critical to get into the hospital. It’s also critical. This is a clot buster and breaks up blood clots. And so the reason we want people in the hospital before we give the medication is we want to first establish one that that person hasn’t had a hemorrhage cause it actually, it’s interesting the signs and symptoms of a hemorrhage versus an ischemic stroke can be identical. If someone’s got a clot that’s blocking an artery, an artery that rupture, you cannot tell the difference looking at someone generally. So the way that we differentiate is by a cat scan. So having someone come in the hospital and get a cat scan is a big part of what we need before we give them clot buster then, then we give them clot buster, recognize that this is the major drug that’s approved by the FDA for treatment of stroke. But it’s unfortunately far from perfect. It improves outcome, and by outcome, I mean disability by approximately 30% at three months. Now keep in mind that’s all comers. And what we’ve seen is that people who present earlier and get treated earlier do better than people treated, you know, so someone at our one after onset does better than someone treated hour to an our three than our four. So this is such an important message to get. The earliest you can recognize the stroke symptoms and get someone into the hospital, the absolute better.
If someone comes in at between three and four and half hours, I would generally expect that the hospital’s going to be a little bit more cautious. And the big issue that we worry about with TPA is the risk of bleeding. And we know that essentially the longer we wait after a stroke, the more leaky the blood vessels in the brain can get where the injuries occurred. And so the more careful we have to be about who giving tpa to, uh, so the question comes up then in someone at three to four and a half hours, we’ll give tpa. In the cases that we can’t give tpa to or beyond, sometimes we’ll be willing to consider something called intraarterial treatment or IA TPA or IA treatment. And with this type of treatment, what ends up happening, and this is kind of like when you get with cardiology, a catheter is inserted into the artery in the leg, and a catheter can be brought up all the way into the brain to where the cloud is actually at. And then there are a few different approaches to actually trying to remove that clot. One is with something called the penumbra device where you actually have a little section and a catheter and you actually try to poke the clot, break up the clot and suck it out. Another way to do it something with something called a stent Trevor, where you actually can put the wire through the clot and open up a stent that grabs the clot and then we can pull it out. Or another option is a direct admission of tpa right at the spot where the clots at hoping to break it up. And so generally that’s been felt to be more of an experimental procedure rather than something that’s been proven by randomized controlled data. I would point out that just recently, earlier this month, the first randomized controlled study has come out demonstrating that actually in some cases intraarterial treatment can actually improve outcomes. Lastly, I would point out that with intraarterial treatment, there are certain cases where we know the IV clot-buster, the IV tpa is less effective. This is in cases where there’s a really large clot in the brain. In some of those cases, and we have to be selective and careful. We can actually use intraarterial treatment to try to break up those clots as well. Those are the main treatments. That is the only real treatment in the acute phase of a stroke.
The second type of stroke is something called a hemorrhagic stroke or a brain hemorrhage. With a hemorrhagic stroke, which is much less common than the ischemic type of blood vessel within the brain actually ruptures. Often the biggest risk factor for something like this is high blood pressure, the blood pressure you can imagine causes the blood vessels to wear down and finally they’ll rupture. They often rupture in very specific areas. These are very dangerous strokes to have occur because of the blood inside the brain, inside the skull can be lethal. Um, but fortunately this is a type of stroke that actually is becoming less and less common because we’re doing such a good job of preventing.
As we move up from the heart, we move up into the carotid arteries and we think about carotid stenosis. And this is something that can be treated medically with aggressive risk factor control, blood pressure, cholesterol and milder blood thinners than what we just talked about, something called Plavix typically or aspirin. And we use aggressive medical therapy if the degree of narrowing is 70% or less. If the degree of narrowing in that carotid artery is more than 70% then often what we’ll choose is to have surgery. And the type of surgery that’s done is something called a carotid endarterectomy and this is where the artery is actually opened up by a vascular surgeon and cleaned out and then sewn back up. And that can be very effective at stroke prevention. Although in someone who’s had a stroke or TIA, we tend to want to do it as early as we can safely do it after the event. There is another option in patients who are at higher risk for surgery and that’s something called a carotid artery stent. And the stent is where, again, where they put the catheter up, the artery up into the carotid artery, and, and just like in the heart, deploy a stent that opens up the artery to allow blood flow to come through. So either of those things can be done, although more commonly here in Tucson, it’s carotid endarterectomy surgery.
As we move up, so then if we’re looking at other types of strokes beyond a fib and carotid stenosis, generally the approach is a multi sort of pronged approach. One, it’s some type of blood thinner. The mainstay, the one that we use the longest is aspirin. Often a question that’s asked is, well what’s the right dose of Aspirin? We don’t know. Somewhere between 81 and 325 and it sort of depends on the case. I would point out in someone using an 81 milligram aspirin, I would advise not using an enteric coated, not using an enteric coated aspirin as it may be less bioavailable. But between 81 and 325, any dose probably works and it sort of depends on the patient and something to talk to your doctor about. There are other types of blood thinners and someone who comes in and it was on aspirin already, we’ll consider other types of blood thinners that may be more effective than aspirin. One’s called clopidigrel or Plavix is the brand name, but it’s available as a generic and another one that’s extended release diaprimonal and aspirin together and that’s got a brand name called agronox. Both of those drugs can be more effective than aspirin at preventing stroke in the right patient. The next thing we want to pay attention to is the cholesterol. And again, I emphasize there is lots of data now that’s out that shows that statins help prevent recurrent strokes and we pay very close attention to what the total cholesterol is and also what that LDL, the bad cholesterol is. And we want that LDL low. Less than a hundred and in some cases less than 70. Next we wouldn’t pay careful attention to the blood pressure. And from my perspective, blood pressure control in the first few days after a stroke is not crucial. We actually let the blood pressure go up a little bit in the first few days with the idea being there’s a clot up there and the body knows how to get blood around that clot and it does it by elevated blood pressure. But over the long term, months for sure, we want that blood pressure well controlled. And that’s often a combination of diet, watching your sodium intake, exercise, and medications. Again, I point out that the disturbing sort of a statistic from the American Heart Association that with high blood pressure, 50% of patients aren’t well controlled and is the major risk factor for stroke in a crucial one for us to control well.
With A-fib, there are four major drugs that we can choose as far as prevention. These are very effective drugs, clearly better than things like aspirin. These are strong blood thinners. The four drugs are warfarin or coumadin. This is the drug that’s been around the longest and we have the most experience with it. The drawback to Warfarin is that it does tend to cause more drug interactions and evolves blood tests on somewhat of a regular basis and careful attention to the diet. There are three newer medications that have just come in the market in the last few years. A drug called Pradaxa, and another called Eliquis and lastly Zeralto. These are drugs that had the distinct advantage of not requiring blood tests, of having minimal drug interactions. The major drawback to them is that there are no blood tests, and so that can make it a challenge if the drug has to be reversed for any reason.
Pharmacogenomics may play an important role in treatment and more specifically prevention of stroke in the future. The way that I see that this playing a role is helping us pick the best medication choices for each patient. And I see this in a few different areas. One, if we give people blood thinners, it seems that there are some people that respond better to aspirin than others. Some people respond better to clopidogrel than others. And the same thing goes with aspirin and extended release dipyridamole. We also see this with blood pressure medications that some people just respond to certain types of blood pressure medications better and so with pharmacogenomics would, I could envision down the line is being able to assess what medications you’re going to respond to best by what your genetics say. You won’t be able to recognize that certain genetic or certain gene types, genetic profiles make you a better candidate for this type of medication and these types of medications. And so we can say, look, you know, for you specifically your body, your genes, you do better on aspirin and hydrochlorothiazide. And this person does better on these medications. And I do think that’s coming down the line at some point.
On top of that, we’re always looking for other ways to more quickly detect stroke, to get someone tpa faster. And one of the really neat things that’s been coming out there, and it’s still too early for primetime, but it’s coming out, are our actual ambulances with a cat scan in the ambulance. So if someone has a stroke, the paramedics are trained to recognize what a stroke looks like, get someone in the, in the ambulance can actually do a CT scan in the ambulance and then more quickly give them IV TPA in the field rather than having them come into the hospital. So that’s a future direction that we may be moving into as well. And then another area that’s been an interesting area, it has been some type of neuroprotection trying to find something that can protect the brain, uh, because often the big problem for us is time is, you know, the time it takes someone to get into the hospital time it takes them to get evaluated in the hospital and then get the tpa going. And if there’s something that we can give them to help protect their brain during this whole evaluation, that would be really, really wonderful. One last area is trying to look at how we can make IV TPA more effective. And an interesting thing that’s been researched and continuing to be researched is using ultrasound to try to augment the TPA. And the idea is if you can locate where the clot is in the artery, you can actually put a device over the skin that’s sending ultrasound waves where the clot is, so that as the tpa hits the clot, it can warm into the clot better and break it up more effectively. And so that’s another area that’s being actively researched that’s exciting.
My name is David Teeple. I’m a neurologist. I’m the director of stroke and I am president of the American heart and Stroke Association for my local chapter.
I’d like to talk next about the epidemiology of stroke. If we look at the nation as a whole, we see close to 800 to 900,000 strokes per year. Fortunately what we’re seeing though, because of our great efforts and the public’s great sort of response is that the incidence of death related to stroke, the number of strokes causing people to die is decreasing. It used to be, approximately four years ago, the struggles, the third leading cause of death. And then it became the fourth leading cause of death. And now it’s the fifth leading cause of death. And so we’re doing a better job of treating strokes, keeping people alive. And one of the things we have to keep in mind is that despite this decrease in the number of deaths, people are still having strokes and it remains the leading cause of long-term disability. And I think we all sort of have the notion that there are fates potentially even worse than death, where you’re left with such disabling problems that life can be very, very difficult. If we look at the stroke types that we have, it’s interesting to see what percentage of each stroke really occur. So with ischemic strokes, we’re looking at about 88% of all strokes are ischemic strokes. So the vast majority of strokes are ischemic strokes, where a blood clot travels up into the brain, blocks an artery, the brain stops working and injury occurs about 9% of all strokes are related to interest, cerebral hemorrhage. So again, that’s where the blood vessel ruptures inside the brain and blood causes injury and presses the brain aside. And then the least common, which is subarachnoid hemorrhage, is about 3%. And the subarachnoid hemorrhage is where an aneurysm, this little bubble, like outpouching ruptures causing sudden onset headache, neck stiffness, and often prolonged hospitalization.
Stroke is a, is a major health issue for the United States and the world in general. When we talk about stroke, I find that often my patients have difficult time really understanding what a stroke is and there’s a lot of misconceptions out there. So first let’s talk about what, what a stroke is when a physician is talking about a stroke. We’re usually talking about three major different conditions. The first and the most common type of stroke is something called an ischemic stroke. And most of the time when doctors are talking about strokes, this is what they’re talking about. An ischemic stroke is where a clot or some type of blockage, actually this could be most commonly a blood clot, but also a cholesterol embolus or cholesterol piece breaks off and comes up into the brain and lands at some point where it blocks an artery. And now that artery can’t supply blood to part of the brain. That part of the brain stops working. So people immediately develop symptoms. From my end, I very much pay attention to what type of symptoms or the pattern of symptoms that people have. Because with a stroke, we know how the blood vessels go in the brain and where they go. And so the symptoms have to correlate to a vascular distribution. The longer that blood clot stays there, the more damage happens. Damage starts happening immediately, and over the course of minutes to hours, that damage can become permanent. That’s why often when we talk about treating stroke, time is of the utmost importance, and that’s something that we will talk more about later when I talk about treatment.
As we move up into the brain, the last type of thing that we often see is actual what we call lacunar strokes, which is essentially a stroke of the tiniest little arteries in the brain. And so what you end up having is you have these big pipes that come up and they split into smaller pipes and off the smaller pipes coming to those little feathery vessels that supply very important areas of the brain and the brainstem. And things like diabetes, high blood pressure, high cholesterol are very hard in those arteries and they can collapse. And essentially what they do is they scar up and then they’ll block off. And we called those lacunar strokes. And those account for our large percentage of the strokes that we see. It’s interesting, the same pathology can actually occur, and instead of that artery blocking off the scar tissue, makes the artery weak and then the artery ruptures. And so in the same places we see lacunar strokes, this is the same place as where we actually can see hemorrhages in some people. Why some people have hemorrhages and other and other people have lacunar strokes where there’s a clot? We don’t know exactly why, but that’s certainly what happens. And again, the key answer or the key sort of take home message in those cases is prevention, prevention, prevention, and it’s blood pressure, blood pressure, blood pressure, cholesterol, diabetes. And so those are the major causes of ischemic stroke that we see, in general, which is cardioembolic often from A Fib, carotid artery stenosis, and then actual strokes from the blood vessels in the brain called lacunar strokes.
With A Fib. This is a disease in which the top of the heart fibrillate. So if we look at a heart, and I’m a neurologist, so I’m gonna look at this sort of basically. I think the hardest two chambers, the Atrium and the ventricle. Blood comes into the atrium, the Atrium squeezes the blood into the ventricle, the ventricles, the big muscle squeezes it and it goes to the whole body. And most importantly, the brain. In A Fib, the top just quivers. It’s not beating like it should. It’s just quivering. But fortunately we’ve got gravity on our side, so blood comes down to the ventricle, ventricle squeezes it up and you’re good to go. Your heart will beat irregularly, which some people can recognize, but many people don’t. What the problem is in this condition is that blood then can sort of sit in the nooks and crannies of that atrium. And when it does that, it coagulates. Clots can form. They can be big clots and they get solid cause they’ve had some time to form. And then gravity is your worst enemy. Gravity, then the clot comes down and the heart squeezes it up, and it goes into the brain and can cause an ischemic stroke. So A Fib is a big deal, and we’ll talk later about how that’s treated or prevented.
Lastly, the third type of stroke, the least common type of stroke, but also the most dangerous type of stroke is something called subarachnoid hemorrhage. With a subarachnoid hemorrhage, what you have, typically is you have a blood vessel with an aneurysm, an aneurysm is sort of a bubble like outpouching of the blood vessel. And with that bubble outpouching the blood vessel wall gets weak. And actually, it’s interesting, with an aneurysm, there are no symptoms. People can’t feel an aneurysm generally. The only time in the aneurysm becomes symptomatic is when it ruptures. And the symptom of that is a sudden onset, worst headache of your life. It just hits like this and people can lose consciousness suddenly. And what happens is that blood then spills around the outside of the brain, uh, causing irritation to the skin around the brain called the meninges, which caused the significant pain, headache, neck stiffness. And for those, it often requires coming to the hospital, potentially surgery to clip the aneurysm, and unfortunately often a prolonged stay in the hospital for monitoring.
Another cause is worth at least recognizing is an infection of the heart. Something called bacterial endocarditis. This can happen in all kinds of circumstances where someone has a blood infection. It can come from IV drug use, but it can happen also in other circumstances where there is no IV drug use. And when the heart gets infected, it often is sort of nebulous. The symptoms can be fatigue, night sweats, weight loss, fevers, and no one can figure out why. And it has to be evaluated with a specific type of echocardiogram called the transesophageal echocardiogram where they actually stick the tube in the throat to look at the heart from the esophagus where there’s no hard sternum in the way. And we can see the bacterial that the bacteria growth on the valve of the heart, which can break off and go up into the brain. And that’s a specific type of stroke that’s treated oddly enough, not with blood thinners, but with antibiotics.
Other risk factors for stroke. Interestingly, there’s, there are, there are the modifiable risk factors and things sort of non modifiable risk factors and there’s a nice way to sort of differentiate what things that you have control over and things you don’t have control over. So a couple more modifiable risk factors that you have control over. Smoking the number one preventable cause of death in the entire world. Smoking. And from my perspective, one less cigarette a day is a victory. Ideally we get everyone to stop smoking completely. Physical inactivity. I talked about it before. It’s important in controlling blood pressure. It helps control cholesterol, it will help with blood sugar and diabetes. But it also helps the brain in other ways promoting good blood flow, amongst other things. And again, what I recommend is 30 minutes, at least four to five times a week of moderate intensity exercise. This is what the American Heart and Stroke Association recommends as well. Then the next modifiable risk factor is obesity. It goes hand in hand with everything else we just talked about. But obesity is an epidemic in the United States. More than 60% of adults are classified as obese. And so whether this is, you know, a combination of not being active enough, diet, and whatever it takes, we need to sort of pay attention to that as a risk factor and address it in any way that we can.
When we talk about stroke, one of the most important things that we need to focus in on are the risk factors and stroke prevention. And these are the things that we all sort of know, but maybe we forget or don’t pay attention to. And one of the best sort of sayings that I always hear because I think people keep in mind what’s good for your heart. And we all know what’s good for prevention of heart attacks. And one of the things you can always sort of remind yourself is that what’s good for the heart is good for the brain. That being said, let’s talk about what are the significant risk factors for stroke. The most important risk factor for stroke far and away is high blood pressure. And it’s interesting of all the risk factors that we have, this is the one that’s most clearly associated with stroke. And you know, then the question is, well, what’s the ideal blood pressure? And no one knows that perfectly. Generally speaking, a neurologist and stroke neurologist once one people at about 120/80. So that’s the systolic over diastolic 120/80 is the blood pressure that’s the goal. It’s interesting though, if we look at stroke studies, any blood pressure and we’re now I’m talking about the top number, the systolic, any blood pressure over 115 bears some increased risk of stroke. So from my perspective, especially in someone who’s had a stroke before the lower I can get that blood pressure, the better. Keep in mind that blood pressure is hard to control. Of the millions and millions of Americans that have high blood pressure, only 50% actually are well controlled. So this is one of those things that it’s important to be talking with your neurologist, your cardiologist, your primary care provider, and recognize that it’s not just medications. Medications play a crucial role in controlling blood pressure, but we need to be doing other things as well, such as watching your diet and particularly the sodium in your diet. And if you look at any package, you can see how much sodium is in any food. And you should be holding yourself, If you having problems with high blood pressure, you should be holding yourself to less than 1.5 grams or 1,500 milligrams of sodium per day. And I’ll tell you, it’s hard to do. It sneaks up on you. And this is a really crucial thing for blood pressure control.
Next. High cholesterol. So high cholesterol is associated with stroke and generally speaking, we follow the national guidelines for stroke prevention or in primary prevention. This means if you’ve never had a stroke before, never had a heart attack before, there are national guidelines on what your cholesterol should be. And it’s sort of, it’s based on how many other risk factors you have. If you’ve had a stroke in the past or a TIA, then the goal automatically becomes a lower and more aggressive. I would point out that generally speaking, statins and there are many statins out on the market. These are really, really good drugs. They seem to have multiple beneficial effects with respect to stroke prevention. First of all, they lower the cholesterol. And when we’re looking at the cholesterol, we’re looking at a specific part of the cholesterol. This is one the total cholesterol and then the LDL, which is the bad cholesterol. And we want that to be as low as possible. Preferably blow 100 and in some cases even lower than that. And statins are very effective at controlling that better often than diet and exercise, although diet and exercise for cholesterol control are also very important. The statins have an extra benefit though, and it’s probably the fact that they work as anti-inflammatories along the vessel wall. So you can imagine things like high blood pressure, diabetes and high cholesterol. They cause injury to the vessel wall. And when that injury happens, you get inflammation in the vessel wall and that’s what causes plaques to occur and narrowing of the arteries. And so we think that statins help prevent some of that inflammation from occurring and prevent that plaque from forming in the first place, which we know is a cause for stroke and actually heart disease as well.
The next big risk factor that we need to pay attention to is diabetes. A diabetes increases the risk of stroke anywhere from three to six times. Nobody knows for sure. Diabetes has multiple effects in the brain. It actually is a risk factor for Alzheimer’s disease as well. The most important sort of piece of information on diabetes and stroke prevention. It’s diabetic control. Watching the diet, watching the number of carbohydrates in the diet and keeping that blood sugar low. Often your primary care provider or your endocrinologist will be looking at your, what’s called an A1c, and they want that A1c nice and low, preferably six or below.
Number two is regular exercise. And the American Heart and Stroke Association recommends 30 minutes a day, four to five times a week of moderate intensity exercise. It doesn’t have to be Gene Simmons sweat pouring down headband on. This is just any type of moderate walking where he just maintained that exercise for 30 minutes straight. And from my perspective, the most important part of an exercise routine is that it’s something you’re going to stick with. If it’s something that’s great exercise but hate it, you’re never going to do it. It’s not worth it. But, so you’ve got to find the things that you like. If it’s dancing, great. You know, if it’s you know, running with the dogs, great. Whatever it is, find that for you.
The non modifiable risk factors are sort of worth, at least recognizing and my sort of view on the non-modifiable risk factors are okay, fine, these are things you have no control over, but it’s worth it to recognize because it’s that much more important to really strangle the modifiable risk factors as best you can. Address them with as much aggression as you can. And so, non modifiable risk factors. So sex. So men have overall, on an age adjusted basis have more strokes than women, but over a lifetime women have more strokes than men. And with women the strokes are actually more lethal or more dangerous when they occur. Age. Stroke is a disease that is much more common as we get older. So recognizing that is an important thing and again, maintaining these risk factors as we age is very important. Next is genetics. If there’s a strong family history of heart disease and stroke, that’s very important to pay attention to. And last is race. And so we know that ethnically wise African Americans have a higher rate of stroke than Caucasians and Mexican-Americans are probably somewhere in between. So again, those are things worth paying attention to. We think that in African Americans, the higher rate of stroke has a lot to do with a higher incidence of high blood pressure. And treating that aggressively is very crucial in that specific population.
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