Stroke and TIA - CRASH! Medical Review Series

hi everyone so this is going to be a section on stroke and here we're going to really just focus on the diagnosis and treatment of strokes we're not going to focus on the specific stroke syndromes so in another section we'll talk about how you can clinically differentiate a stroke based on the artery that's that it's affecting but here we're going to talk about how you treat in general all strokes so there's another name for a stroke which is sort of an equivalent if you want to think of heart attack or mi versus angina you can kind of think of stroke too transient ischemic attack so it's not as severe but there are symptoms so transient ischemic attack is another word you hear thrown around and what that is is it's just neurologic symptoms that's due to to hypoxia of the neurons so some fundamentals of stroke nearly 800,000 people have strokes every year in the United States around 90 percent of those strokes are ischemic which is of course a lack of blood flow whereas about 10% plus or minus a few are hemorrhagic and hemorrhagic of course means that it's due to bleeding inside the cranial cavity and of course the hemorrhage can either be due to an aneurysm either a berry aneurysm or another type of aneurysm or it can be due to trauma although strokes typically manifest in people who are older we think about our typical stroke patient we think of an elderly person about one in five strokes actually do happen in younger adults and in children so that's really important to remember not to stereotype somebody symptoms just based on their age that if somebody comes in with focal neurologic symptoms that are of acute onset you really have to have to include stroke in your differential diagnosis the most prevalent symptoms surrounding stroke include facial drooping one sided arm or leg weakness verbal deficits which could be slurring it could be dis are three a' it could be aphasia or verbal like nausea so slurring of course self-explanatory dis are three I is a difficult time moving the the mouth and the jaw so you can't create the phonemes to make speech aphasia is an inability to produce language and then verbal leg nausea is an inability to understand or comprehend language and then mostly all stroke patients have some level of altered consciousness other symptoms can be present as well particularly in the stroke syndromes that occur in the posterior posterior circulation so eight axia imbalance visual field deficits vertigo and so forth and of course has mentioned the symptoms are going to depend on the location in the cerebral circulation whether it whether their cerebellar symptoms present like imbalance whether there's vertigo present whether it affects the upper limbs or the lower limbs whether speech is affected and so forth provided that the patient is stable the best initial step is going to be a non-contrast CT of the head this is your best initial step in diagnosis and this is important because it's going to help you distinguish whether the stroke is ischemic or if it's hemorrhagic now as far as a differential diagnosis what things could it also be besides stroke based on the symptoms you have of course it's going to be dependent on the symptoms that you have so of course if a patient comes in with vertigo then of course you could include on your differential Munir syndrome or an infection your affection if the patient has simply facial drooping you could you could include the differential of Bell's palsy any of these symptoms can be included in something called Todd's paralysis which is a post echo state after a seizure you can develop focal neurologic deficits that are generally temporary so there is a differential for stroke but in general its acute neurologic deficits generally in older patients and the initial diagnostic step is going to be a non-contrast CT of the head so what does the stroke patient look like in general they're patients that struggle with hypertension hypertension is the number one risk factor for stroke also hypercoagulability so we look for hiker hypercoagulability particularly in the younger patients that come in with possible stroke so any of the inherited hypercoagulable States factor v leiden protein c or protein s deficiency that can be associated with increased risk of stroke and then the acquired factors so oral contraceptive drugs and estrogen use hyperlipidemia is another is another risk factor for stroke because it can clog your arteries diabetes obesity and amyloid angiopathy hypertension is the one i really want you to remember hypertension and then hypercoagulability the symptoms as mentioned for stroke are an altered level of consciousness facial drooping one sided arm or leg weakness which can be hemiparesis or it can be hemiplegia so hemiparesis meaning that you don't have you don't have sensation hemiplegia meaning that you don't have you don't have strength verbal deficits like slurring dysarthria aphasia and verbal agnosia i have a lot of spelling errors I'm sorry about that and then gait disturbances and also I didn't write on here visual deficits visual field it's particularly Amana mess hemianopsia so you should always include stroke in the differential in any patient with acute onset focal neurologic deficits as I mentioned regardless of their age so the first initial step is going to be a non-contrast CT this is your initial diagnostic step of course provided that the patient is stable the most accurate test happens to be a diffusion weighted MRI that's the most accurate but it's rarely performed because it takes a lot more time than just getting a head CT the CT has to be done to differentiate between ischemic and hemorrhagic and it also is important in case there's any injuries or anything else going on you also need to get a routine set of labs in which I would include always a CBC a CMP INR s and something that contains the glucose level reason being is that you want to have a background of what this patient has whether they might be struggling with if there may be any infection going on if there's any electrolyte abnormalities you want to have their glucose levels because there's a specific treatment that we like to use in patients with stroke that we can't use if their glucose is too low same with the INR if their INR is too high you can't use that particular treatment and then we also should get an EKG on any patient with a stroke 12-lead EKG because atrial fibrillation is a risk factor for stroke and we want to see if that's going on emergency treatment while you're waiting for or on the CT that you can administer to the patient that you should certainly administer right away if there's instability would be supplemental oxygen or airway management and generally we employ this if the if the saturation is less than 94% this can be by facemask it can be nasal canula I can even be intubation if you need to generally face mask or nasal cannula will be good enough but certainly you're going to take whatever steps necessary to keep the patient oxygenated blood pressure control is useful generally if we only need to do it if the patient is over 220 millimeters of mercury if we're going to employ a clot-busting then we'll have to have it even lower than that but for the get-go you can administer a low beta while need administer labetalol if the blood pressure is greater than 220 systolic and then you're going to want to treat hypoglycemia if it's less than 80 milligrams per deciliter and then treat a fever if they have one that of course is 100.4 as fever is defined you can give them acetaminophen either P o or rectally if they're up ten David so this is just a sort of review of the circulation we're not going to talk about stroke syndromes here most strokes occur in the ACA or the MCA so this will give rise to either upper or lower hemiparesis or hemiplegia of course you have lots of arteries so there are lots of different syndromes that you can get but we have to get that CT first to really be able to tell for sure where the lesion is but you can usually predict it clinically in the USMLE is going to want you to be able to make an educated guess based on the symptoms we'll talk about that in the other section okay so ischemic strokes make up 90% of all strokes so that's the vast vast majority and most of the ischemic strokes are thrombotic so what is thrombosis it's stenosis of the vessel so this is not any thrombosis is thrombosis of a vessel that is responsible for supplying oxygen to an important part of the brain now of course all parts of the brain are important but only the strokes we see are diagnosed as strokes so usually this is dudas gnosis of a critical vessel like the MCA or the ACA or the posterior communicating artery or the pica so most strokes are thrombotic and remember that the major risk factors for stroke are similar to the major risk factors for heart attack and heart attack is also a thrombotic disease another type of ischemic stroke is embolic so why do we think of when we think of embolism the big thing we think of is DVT we think of like what causes pulmonary embolism and DVT is usually associated with pulmonary embolism okay so ischemic stroke so ischemic strokes make up the vast vast majority of strokes about 90% and out of the ischemic strokes if you break them down most of them are thrombotic so thrombotic is stenosis of a critical vessel most strokes are are thrombotic and when they're diagnosed they're found to be in the MCA or the ACA or the pike and based on what vessel is being affected it will give us the specific symptoms remember that the symptoms are the sorry the risk factors for stroke are similar to the risk factors that we have for myocardial infarction and that's because they're both robotic diseases so hypertension hypercholesterolemia obesity smoking those all increase your risk of stroke another type of stroke is embolic so an embolic stroke is due to an embolism from a distal site and it also blocks a vessel but here instead of having stenosis we have an embolism from a distal site so the major risk factors for this include atrial fibrillation and DVT so atrial fibrillation is pretty easy to figure out why that happens when you have atrial fibrillation you have an atria that's really not moving properly it's not pumping as strongly as it should it's just fluttering so what happens in that left atrium is that you can get the buildup of a thrombus of an embolism and this embolism grows over time and if it passes into the left ventricle it can pass into the general circulation now how do you go into the general circulation you go from the left ventricle to the aorta now depending what will you go if you go left or you go right either way you can go up to the brain either you go through the left into the arch of the aorta through the left common carotid or you go to the right take a detour through the inanimate our artery and get into the right common carotid both ways you can wind up in brain circulation and that can cause a stroke so atrial fibrillation is a big risk factor for a stroke and indeed in most patients who have atrial fibrillation we are treating them with anticoagulants because they are at a much higher risk for a stroke another thing that can cause embolic stroke is DVT now DVT you may be wondering doesn't that cause pulmonary embolism and yes it does we normally associate DVT with pulmonary embolism however there are a lot of patients who have what's known as a patent foramen ovale and as you probably remember patent foramen ovale is a hole in between the left and the right circular left in the right heart between the left and right atrium and so Reta in most patients who have DVT if they get a thrombosis it goes up the inferior vena cava into the right heart and then from the right heart into the pulmonary arteries and can cause a pulmonary embolism however if you have a patient who has a PF o what can happen sometimes is if they get a DVT and they get an embolism that embolism can pass into the left heart and if it passes into the left heart then it's just like an embolism from an atrial fibrillation it goes from the left ventricle up into the arch of the aorta or up into the right and Ottoman artery and there you go you can get an embolism from a DVT as well so both atrial fibrillation and to a lesser extent DVT are risk factors for embolic stroke a lacunar stroke is a blockage of a smaller penetrating vessel so you can think of it as a little less severe because of happening in a smaller artery or arteriole and it's much more subtle usually it presents with only a few neurologic deficits certainly it's much different than if you block a big part of the ACA or a big part of the see a so these can be the kinds of strokes that rather than present with both with both sensory and motor deficits maybe it only presents with motor deficits or maybe it only presents with sensory deficits or maybe you can move both sides but you kind of lose balance so when you have fewer neurologic deficits but it still presents similar to a stroke its acute that may be a lacuna or stroke and these are all ischemic strokes how about hemorrhagic strokes most of these tend to be a subarachnoid hemorrhage and most subarachnoid hemorrhages come from aneurysms so subarachnoid hemorrhages come can come from aneurysms they can also come from trauma but usually that will be in the history so subarachnoid hemorrhages tend to be just ruptures of aneurysms and how do these prevent present they present in patients mostly because of the headache and subarachnoid hemorrhages are known they are very notorious for being the worst headache of my life the patients will say most often that's a tip-off USMLE likes to use that it's also known as a thunderclap headache because it happened so suddenly you think of it you have an aneurysm in your brain pop and you got bleeding and that headaches going to happen pretty fast so you should particularly consider this in acute focal neurologic symptoms accompanied with a headache like I said usually it's due to a ruptured aneurysm and you should be aware of the saccular berry aneurysms they're technically called secular aneurysms but a lot of people come in very aneurysms and they have a tendency to show up in particular arteries they like to show up in the communicating arteries that either the anterior communicating artery switch both give off the the anterior cerebral arteries and the posterior communicating artery then they can also happen in the MCA those arteries those three artery together make up about 75% of Faerie aneurysms other risk factors for berry aneurysms include this shame mnemonic so Sh AME smoking hypertension and then definitely remember these diseases adult polyposis kidney disease Marfan syndrome in ehlers-danlos syndrome the reason that these are associated with very aneurysms is because they're associated with mutations of connective tissue which are also important for the construction of blood vessels so the treatment if it indeed is a hemorrhagic stroke is going to be surgery and pretty much all patients they're going to need coiling that's the new sort of the new trend as opposed to flipping but either of those are fine hemorrhagic strokes though do need to be managed surgically if not just for the to fix the vessel to drain the hematoma management is going to focus on reducing the blood pressure in cases of hemorrhagic stroke you want to get the blood pressure much further down because the higher the blood pressure the faster you're going to bleed in the in the cranium so you want to get the blood pressure below 160 systolic nice harder pain is the most commonly employed antihypertensive for stroke and that's going to be either even if it's hemorrhagic or ischemic we tend to use neck harder pain to get the blood pressure down and of course if the patient is on warfarin then you're going to want to administer fresh frozen plasma to any patient with a hemorrhagic stroke because we want to reduce their bleeding you should be vigilant for seizures and this goes for any patient with increased intracranial pressure and you do have that in hemorrhagic stroke and keep the patient inclined to 30 degrees that will help keep your intracranial pressure under control okay so we're going to spend most of our time talking about the treatment for is chemic stroke and an ischemic stroke if the diagnosis is indeed ischemic which it usually is the question is going to be whether the patient is eligible for thrombolytic therapy with TPA for our TPA which is just recombinant TPA tissue plasminogen activator usually we use l to place there's also right a place and streptokinase but l to place is the one that's used most often in a clinical setting now there is no benefit to heparin coumadin or any kind of anti platelet administration for an ongoing stroke certainly they are useful for for for preventing strokes but when you have a stroke what's the problem you have a clot and heparin coumadin and antiplatelet drugs they don't break clots they help you prevent forming clots the only thing that breaks clots is tissue plasminogen activator so if the question is an active stroke patient and ask you heparin coumadin or antiplatelet drugs like plavix the answer is no so the question is when is a patient eligible for TPA and really the question is when's the patient not eligible for TPA because there are a lot of contraindications and actually they just changed this past year and there were a couple things that were taken out as contraindications and just made to be relative contraindications so these contraindications are all absolute so I kind of started with the more obvious ones and ended down here with the less obvious ones so a stroke or significant head trauma in the past three months note so that would make the patient that would rule the patient out arterial puncture in a non compressible site in the past seven days that rules a patient out if you can't compress a place where a patient probably has a clot that's blocking bleeding then you can't give them something that's going to probably break that clot if they have any kind of ongoing inter leading or ongoing trauma then of course you can give them something to break the clock because they're going to need clots to block off the internal bleeding if their blood pressure is over 185 over a hunt 110 then the answer is no however you can use you can use knife harder pain or even nitroprusside for that matter to acutely lower the patient's blood pressure to make them eligible but until their blood pressure is below one 85 systolic you cannot administer TPA you can also not administer TPA if their INR is above 1 point 7 some places use 1 about 1.5 just make sure though that the INR is is around 1 or close 1 close to normal platelets should be above 100,000 that's generally most patients it's unusual for a patient to have platelets below a hundred thousand of course the patients who wouldn't would be the lymphoma patients cancer patients etc elevated PTT is a contraindication glucose lower than 50 is a contraindication now remember when I said you get your glucose level as soon as the patient comes in so that now you already know if the patient's glucose level is okay and in a lot of patients who have stroke they have hypoglycemia as well why I don't know but you've got to make sure that they are normal glycemic before you give TPA that's really really really important so make sure the glucose is above 50 if it's not you can administer glucose and then get the TPA any past medical history of an intracranial bleed rules out TPA so if they have a history of a subarachnoid hemorrhage in the past or an epidural hematoma in the past no TPA and then if the infarct is multi lowbar meaning that they have multiple of the areas of infarction rather than just one then TPA is not not going to be useful if indeed the patient is eligible for TPA you should administer it as quickly as possible it's preferable that within an hour to 90 minutes from the onset of symptoms that the patient gets TPA three hours has been set as the window meaning that's sort of the time at which after which TPA becomes less and less useful however it's sort of become the talk now that that window maybe up to four and a half hours but you want to get it within at best within 90 minutes and and hopefully within three hours so post stroke management all stroke patients need to be administered to a neurological ICU if there's one present stroke unit or a medical intensive care unit of course if they're hemorrhagic stroke they'll probably be administered to a surgical intensive care unit for hemorrhagic stroke of course we're going to defer management for that to surgeons and certainly in a way I make some surgery review videos I will talk in more detail about how we manage hemorrhagic strokes so ischemic strokes all stroke patients should be given aspirin as a prophylaxis for secondary stroke some patients a minority are allergic to aspirin in that case we can give them clopidogrel or diaper it amol as a substitute if a patient has another stroke and they're already been on aspirin then you should give them either clip integral or diaper it Amal addition to aspirin it's not uncommon for a patient have a second stroke after they've already been admitted seizure prophylaxis is not necessary however it's important to know that it is a possibility about 1 in every 5 stroke patients do have seizures after their stroke and so you should definitely be ready have lorazepam or diazepam whatever whatever you prefer they're both pretty much the same thing on standing borders so that if a nurse needs to administer it if the patient does become if they do have seizures that they can have that administered as soon as possible if their EKG which you should have already got as soon as they came in as part of your initial assessment if it showed atrial fibrillation then you should be managing them with warfarin up to an INR of 2 to 3 and a calcium channel blocker which is used to manage the actual arrhythmia now remember we never start patients on warfarin when they're in the hospital because of the possibility of warfarin skin necrosis so we would actually start them on a low molecular weight heparin or just unfractionated heparin for two days and then we can start warfarin on day 2 and we want to get them to an INR between 2 & 3 echocardiography is necessary for any patient with ischemic stroke because we want to check and see if they have a patent foramen ovale carotid angiography is is necessary to do if just to see if the patient has blockage of their carotid artery if indeed they do then they're going to be referred to surgery for either carotid endarterectomy or for stenting and then of course like for most diseases lifestyle modifications activity is appropriate change in diet if it's a high cholesterol diet and so for anticoagulation can be useful not just in patients with with atrial fibrillation but in other stroke patients as well a true anticoagulation may be useful you can use heparin or low molecular weight heparin warfarin which is the most common coming out now are the factor 10 blockers Eliquis Pradaxa those are useful because unlike heparin and warfarin you can take those drugs at home and you don't have don't have to have your INR monitored every month so those are the new drugs that are coming out a pink Seban I believe is the name of Eliquis and then rehabilitation a lot of stroke patients will come out with some residual neurologic deficits but they can be they can be overcome with appropriate physical rehab and then just a flashback to cardiology you should definitely remember your chance to score so chads2 is just a mnemonic and this is for patients with atrial fibrillation so this is of the utmost importance in any patient with afib and it's to assess their risk of stroke so chads2 is just CH a D and then those are each a point and then stroke is two points so that's why it's two comes after the S so the C stands for congestive heart failure symptoms which would be one point hypertension is the H that would be one point and that also includes patients who are treated hypertension too so if they are hypertensive or if they're treated for hypertension that's a one point either way if their age is more than 75 years that's a point if they have diabetes mellitus that's a point and if they have had a stroke or TIAA that is two points so the way the score works is pretty easy if they're zero points which is pretty much none of these patients but if they're zero points or one point then you can give them aspirin every day that's fine if they're one point or higher if they're one point they have a choice taking aspirin every day over one point though or higher you should always give them the choice of taking a anticoagulant like warfarin to an INR of two to three so any patient who's had a stroke who has atrial fibrillation they're automatically above one point so that's why we always put them on an anticoagulant and get them to an INR between two and three as you can see here the annual risk of stroke goes up significantly as these points go up there's also something called called the chads2 vask score it's a little more complicated I like this one it's easy to remember less complicated easy to run over these scores and then for atrial fibrillation remember that the antiarrhythmic is in general a calcium channel blocker and that is it for stroke

Channel: Paul Bolin, M.D.

Views: 147,172

Rating: 4.8912868 out of 5

Keywords: Stroke (Disease Or Medical Condition), Health (Industry), Medicine (Field Of Study), Neurology (Medical Specialty), United States Medical Licensing Examination, Health Care (Industry), Health Care Provider (Profession), Pharmaceutical Drug (Medical Treatment), Nervous System (Anatomical Structure), Transient Ischemic Attack (Disease Or Medical Condition), new drugs, physicians, health insurance, medical education, disease, biomedical, malpractice attorney

Id: HD5cJcJTZmk

Length: 32min 42sec (1962 seconds)

Published: Sat Nov 21 2015