[0:00]Okay, so today we are going to talk about stroke. We'll talk about different types of stroke, what are the arteries that supply brain, and what if those arteries are blocked, what are the body parts that are affected? How do you manage a stroke patient in emergency? What is the acute treatment of stroke and what is the chronic therapy for stroke patient? Today, we are going to talk about that. First of all, we will define stroke. Stroke is defined as interruption or reduction of blood supply to an area of brain that results in the brain death. That is called as stroke. Stroke has two types, ischemic stroke, hemorrhagic stroke. In ischemic stroke, the artery that is supplying brain, that artery is blocked. That is called as ischemic stroke, that results in the death of brain tissue. And when that artery is ruptured, that is called as hemorrhagic stroke. And blood supply to the area ahead of that artery is blocked. Ischemic stroke is our main focus of this video, but we will briefly talk about hemorrhagic stroke as well. Hemorrhagic stroke has various types. Subarachnoid hemorrhage when the bleed is around the brain. Intraparenchymal hemorrhage when bleed is within the brain. Ischemic stroke can be of two types, either embolic or thrombotic. Embolic strokes are the one in which clots from anywhere in the body get they get stuck in the vessels that are supplying the brain resulting in blockage of blood supply to the brain and tissue death. Those emboli can be due to atrial fibrillation or can be due to endocarditis. Both are the conditions in which clots are being formed in the heart and those clots block the arteries of the brain. Thrombotic stroke results from chronic atherosclerosis, deposition of fats within the vessels. That deposition of fats decreases the lumen size of the vessel resulting in decreased blood supply to brain and stroke. The risk factors of thrombotic stroke are same as coronary artery disease. They are hypertension, diabetes mellitus, smoking, and genetics. Now we'll talk about blood supply of brain. Blood supply of brain mainly consists of anterior circulation and posterior circulation. Anterior circulation arises from internal carotid artery and posterior circulation arises from vertebral arteries that arise from the vertebrae. Anterior circulation includes anterior cerebral artery and middle cerebral artery. Posterior circulation includes the vertebral arteries, basilar artery, and posterior cerebral arteries. All of these arteries combine to form Circle of Willis. Now, we will discuss what if these different vessels are blocked. What are the areas of the body that are affected by the blockage of these vessels? Remember, any stroke in the brain always affects the opposite side. If there is stroke on the left side of the brain, it affects the right side. If there is stroke on the right side of the brain, it affects the left side of the body. If anterior cerebral artery is blocked, that results in stroke that affects leg and feet much more than the upper limb. It also affects the upper limb but legs and feet are prominently affected in anterior cerebral artery stroke. Middle cerebral artery affects face, arm and speech of the patient. Speech is very important. If the speech of patient is affected, suspect middle cerebral artery stroke. If posterior cerebral artery is affected, it mainly affects the eyes. When paramedian arteries are affected, it damages pons, and damage to the pons result in Locked in Syndrome. In Locked in Syndrome, the whole body is paralyzed except the single body part, the eyes. Eyes have intact vertical movement. Other than that, the whole body is locked in itself, the person is paralyzed and locked in his own body. If vertebrobasilar arteries are affected, the main symptom is syncope. And cerebellum is also supplied by vertebrobasilar arteries, so patient will also have ataxia. Syncope and cerebellar symptom point toward vertebrobasilar artery damage. Now, whenever a patient presents to you with a focal neurological deficit in your clinic, that focal neurological deficit can be a unilateral weakness of the body, paralysis of the body, sudden loss of vision, severe headache. All these symptoms are focal neurological deficits that can be caused by stroke. The first thing that you have to do is you have to order a non-contrast CT scan. Since taking contrast will take time, non-contrast CT will give you results more rapidly than any other scan. What we are trying to do in non-contrast CT scan? We are trying to look at blood in the CT scan. If there is blood present in the CT scan, it points out toward diagnosis of hemorrhagic stroke. If there is no blood in CT scan, it is ischemic stroke, so we want to see whether there is blood in the CT scan or there is no blood in the CT scan. Because both ischemic and hemorrhagic stroke have totally different managements. This is a CT scan showing blood in the brain. This white area shows bleed, blood is white on CT scan. And if you see blood on CT scan, it is a hemorrhagic stroke, and you have to initiate your protocols for hemorrhagic stroke. The only thing that a clinician or an internist can do in hemorrhagic stroke is they can lower down the blood pressure to decrease bleeding. Rest is the job of neurosurgery department. They have to refer the patient to neurosurgery and neurosurgeons will either go for craniotomy in which they open up the skull and decrease the pressure in the brain, or they go for coiling and they pass a coil in the vessel and stop the bleed, or they clip the vessel by opening the brain. So that's how you manage hemorrhagic stroke. In this video, we'll be mainly talking about ischemic stroke. What if you see no blood in CT scan? What if you receive CT scan like this in which there is no white area, no blood? And instead you see a black area like this, this black area shows ischemia. White is blood, black area is ischemia in CT scan. Usually you do not see any changes in the CT scan immediately when the patient presents. These ischemic changes take hours to develop and CT scan is mostly normal but the patient is having a focal neurological deficit. The main purpose of CT scan was to exclude blood, to exclude hemorrhagic stroke. Now we know that this focal neurological deficit is due to ischemic stroke and we have to treat the patient according to the ischemic stroke protocols. Ischemic stroke can also present like this, you can see a dark area on this CT scan that shows the middle cerebral artery being blocked. Whenever a patient presents to you with ischemic stroke with no blood on CT scan, the most important decision that a doctor has to take is that whether patient should be given TPA or not. TPA is a tissue plasminogen activator that breaks up that clot that is blocking the blood vessel. But when you are breaking up that clot in the blood vessel and reinitiating blood flow to the brain, there is always a risk. There is always a risk that that ischemic stroke can become hemorrhagic, that by breaking that clot, you can convert an ischemic stroke into hemorrhagic stroke. So there is high risk that when you give TPA, that ischemic stroke can become hemorrhagic, that decision is the most important. Usually TPA is given to a stroke patient if they present within 4.5 hours of focal neurological deficit. Or within three hours if the patient is diabetic and with a focal neurological deficit. If the patient presents after 4.5 hours, or if the patient has contraindications to TPA and you cannot give TPA to that patient, that patient is given aspirin. Now, that is the emergency treatment that you gave to the patient. Now, either the same day or the next day, you will have to do certain investigations to find out the cause of this stroke and to prevent recurrence of that stroke. In those investigations, the most important is ECG, in which you look for atrial fibrillation, atrial flutter that can cause embolic stroke. You go for Echo to look for clots, and you go for carotid ultrasound to look for atherosclerosis in the blood vessels. If you do ECG and you find atrial fibrillation or atrial flutter, you will have to start patient on anticoagulants. In anticoagulants, you can give warfarin or any other novel oral anticoagulant drug. Usually, whenever you start a patient on warfarin, you need to give a heparin bridge. But in these patients, in atrial fibrillation, you do not give any heparin bridge. If you do Echo and you find clots in heart, you will have to go for anticoagulation. Now coming to an important investigation, carotid ultrasound in which we are trying to find out atherosclerosis in the blood vessels supplying the brain, in the atherosclerosis in the carotid arteries. If that atherosclerosis is causing less than 70% stenosis, less than 70% blockage of the carotids, and there are no symptoms, that patient needs to be treated medically, in which you give statin drugs to stop this atherosclerosis process that is blocking the blood vessel. If the patient has greater than 80% stenosis or greater than 70% stenosis with symptoms, that patient needs to be treated with surgery. In surgery, you have options like carotid endarterectomy or stenting. This is a picture showing carotid stenting. If you see, these are all the atherosclerotic plaques that are blocking the blood vessel, and a wire is being passed, and a balloon is being inflated that opens up that blocked blood vessel. That is called as carotid stenting. This is a picture showing carotid endarterectomy, in which this, these are the blood vessels and this yellow part is a plaque, atherosclerotic plaque that is blocking the blood vessel. Then that blood vessel is opened in carotid endarterectomy and that atherosclerotic plaque is removed. After removal of atherosclerotic plaque, that vessel is stitched back into its normal position. That is called as carotid endarterectomy. So you can go for either carotid endarterectomy or stenting if there is greater than 80% stenosis or greater than 70% stenosis but with symptoms. What are the other investigations that you need to do for the risk assessment of the patient? You have to check HBA1C to look for diabetes, you have to go for lipid profile, you have to go for complete blood count, coagulation profile, PT, aPTT and TSH if there is evidence of atrial fibrillation. Now what is the acute management of stroke? In acute management of stroke, as we talked, the most important decision that a doctor has to take is to give TPA or not. If the patient has ischemic stroke and that patient is diabetic and they are presenting within three hours, that patient is usually given TPA. If the patient is having ischemic stroke and they are non-diabetic, and if they present within 4.5 hours, according to the neurological deficit, that patient is usually given TPA. And TPA is not given to patient if they present after this time, or if the TPA was contraindicated, as it is in intracranial hemorrhage, history of bleeding, recent surgery or any recent trauma, because TPA will undo each and every clot in the body, resulting in rebleeding. Heparin is not used in the acute management of stroke. If the patient did not receive TPA or if the TPA was contraindicated or if the patient presented after three hours, four hours, then that patient is usually given aspirin 325 mg. Blood pressure control in acute management of ischemic stroke is very important. While in hemorrhagic stroke, we lower down the blood pressure, in ischemic stroke, we do not lower down blood pressure very rapidly, and we let the blood pressure stay high. That is called as permissive hypertension. Why do we allow the hypertension? Why do we allow the blood pressure to stay high? Because the blood vessel that is blocked, the high blood pressure is an adaptive mechanism to push blood through that blocked vessel. So that dead area is receiving little bit blood due to this high blood pressure and if you lower down the blood pressure, it will cause further damage because that little blood that was even flowing through that blocked vessel due to high blood pressure will now stop. And patient will have more ischemic damage. So that is called as permissive hypertension.
[12:55]If the patient is having ischemic stroke and no TPA was given, usually blood pressure is kept below 221,110. If the patient is given TPA, now you have to lower down the blood pressure less than 180 to less than 105 to decrease the risk of conversion of ischemic stroke to hemorrhagic stroke, as we talked that it can occur with TPA. So it is still kept below 181,05 but it is not lowered down very rapidly. In hemorrhagic stroke, you lower down the blood pressure to less than 150 to 80. So in hemorrhagic stroke, you lower down the blood pressure. In ischemic stroke, you let the blood pressure stay a little high, that is called as permissive hypertension, especially if there is no TPA given to patient. If TPA is given, the blood pressure is still lowered to less than 181,05. If the patient is diabetic, you have to control blood sugar but a very strict control is not recommended. Chronic management of the patient with stroke includes, no TPA in chronic management. Heparin, yes, if the patient has risk of DVT, usually these patients are paralyzed and these patients are highly prone to develop deep vein thrombosis, prophylactic low dose low molecular weight heparin can be given in chronic therapy. In antiplatelet therapy, aspirin is given. If the patient has first stroke, low dose aspirin, usually 81 mg is given. If the patient's condition is still not controlled with aspirin, and there is repeat stroke, the patient is given aspirin with dipyridamole. And if the patient has aspirin allergy, patient is shifted to clopidogrel. Just like in coronary artery disease, where we combine aspirin and clopidogrel, in stroke, aspirin and clopidogrel are not combined. Dual antiplatelet therapy of aspirin clopidogrel is not recommended. In chronic management, you control the blood pressure preferably with ace inhibitors and diuretics. And if the patient is diabetic, you control the blood glucose, you bring it down to less than 7%. Statin therapy is very important to stop the atherosclerotic process of the blood vessel to control the lipid profile, you give high potency statin, atorvastatin either 40 mg or 80 mg, depending upon the patient. Anticoagulation is not given in the acute management, but in chronic management, anticoagulation is given if the patient has indication. If the patient had atrial fibrillation, as we saw on the ECG, if the patient has A-fib plus stroke, the CHADS score is 2 plus, you have to start the patient on warfarin and novel oral anticoagulant drug, and most importantly, you have to ask the patient to quit smoking. In chronic management, in rehabilitation, you have to go for speech therapy, occupational rehabilitation and physical therapy, since the patient is paralyzed. In summary, we talked about different types of stroke, ischemic stroke, hemorrhagic stroke. We talked about different blood vessels and different areas of the body that are affected with those blood vessels. We talked about CT scan, the most important initial investigation in which we see whether there is blood or there is no blood. If there is no blood, you go for either TPA or aspirin, and then in investigations, you go for carotid ultrasound, ECG, Echo. In acute management, TPA is given, antiplatelet therapy, aspirin 325 if the patient did not receive TPA. Control blood sugar. In chronic management, statin therapy is most important and patient's blood pressure and glucose levels are controlled. If you liked my video, please click on the subscribe button to stay updated about all my new videos on emergency treatments.
