Understanding Stroke Risk and Treatment

Understanding Stroke Risk and TreatmentDr. Andre G. Douen, MD, PHD, FRCPC, FAHAStroke Neurologist,Director, West GTA Stroke Program,Chief division of Neurology, Trillium Health Partners, Mississauga, ON Canadawww.educatehealth.caAll rights reserved. This document contains the confidential and proprietary information of Innovate Research and Development and its affiliates, and any disclosure, copying, distribution or unauthorized use of this document without the express written consent of Innovate Research and Development is strictly prohibited. 1ISCHEMIC STROKEWhat is a Stroke ?Sudden loss of brain function due to reduced or complete blockage of blood flow in any part of the brain.

Ischemic or non-bleeding stroke: Accounts for 85% of all stroke and occurs when a blood clot blocks a blood vessel in the brain.

Hemorrhagic or bleeding stroke: Accounts for 15% of all stroke and occurs when a blood vessel breaks within or around the brain. Example: Aneurysm rupture.

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3What are the symptoms of stroke ?Symptoms come on abruptly and depend on the area of the brain affected and the extent of brain damage. Sudden weakness or numbness especially on one side of the body (facial weakness, drooling, limb weakness, unsteady walking).Trouble speaking or understanding. Loss of vision in one or both eyes. Dizziness in association with other symptoms e.g. weakness, numbness, speech or swallowing difficulty. Dizziness or vertigo without other neurological symptoms, particularly if made worse by head movements, suggests inner ear dysfunction rather than stroke. Sudden explosive headache that come on within seconds might suggest an aneurysm rupture. Gradual onset severe headache that comes on over minutes are often due to migraine or other types of headache. However, seek medical attention if concerned.

www.educatehealth.ca4Who are at risk of stroke?Non-modifiable risk factors: Age: Risk of stroke increases with age. Gender: Men may have a higher lifetime risk of stroke, but women have worse outcome from strokes.Family history: Often refers to premature vascular disease. If parents or siblings sustain a stroke before the age 55yrs, then the risk of stroke is higher as compared to individuals who do not have stroke in first degree relatives. Ethnicity: First Nations people and those of African or South Asian descent are more likely to have high blood pressure and diabetes, and are at increased risk of heart disease and stroke. Hemorrhagic stroke is also more prevalent in some Asian (Oriental) populations.Prior stroke or TIA (transient ischemic attack): Previous stroke or a transient ischemic attack (often called mini-strokes), increases the risk of recurrent stroke.Prior heart attack: Is associated with increase risk of stroke www.educatehealth.ca5Who are at risk of stroke?Modifiable risk factors:High blood pressure (hypertension)Atrial fibrillation (irregular heart beat)SmokingDiabetesHigh cholesterolOverweightExcessive alcohol consumptionPhysical inactivity (sedentary lifestyle)Illicit drug useStress

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How do stroke risk factors actually lead to a stroke?ATHEROSCLEROSIS: Plaques within blood vessels of the neck (or brain) can lead to clot formation which blocks blood flow and cause stroke. Carotid vesselBlocked by a clot CT Scan of Brain showing alarge ISCHEMIC stroke

Carotid vesselblocked by a clot8Atherosclerosis: Blood clots formed at the site of a plaque can EMBOLIZE, i.e. flow upwards and block blood vessels within the brain. Carotid vesselBlocked by a clot

9Atherosclerosis: Also leads to weakening of the blood vessels within the brain which can rupture and cause hemorrhagic strokeCarotid vesselBlocked by a clot CT Scan of Brain showing alarge hemorrhage (bleed)

10ATRIAL FRIBRILLATION

How do stroke risk factors actually lead to a stroke?Atrial fibrillation (AF) is an irregular beating of the atria (the 2 top chambers of the heart). AF can lead to clot formation. The clot (or thrombus) then drift into the ventricles (the 2 lower chambers of the heart) and are pumped out of the heart into the brain, where blockage of a blood vessel leads to stroke. The travelling clot is call an embolus. AF is associated with aging, high blood pressure, heart disease, excess alcohol, and overactive thyroid gland.

11Cardiovascular disease is a result of a multifactorial process of which lipids are only one of many factors. Embolization and Ischemic Stroke

www.educatehealth.ca12Is stroke common in young people?Stroke can occur in anyone babies, children, teenagers, young and middle aged adults as well as the elderly.While stroke occurs more commonly in the elderly it is not uncommon in young individuals.In infants the causes are unknown in about 30% of cases, while other causes include abnormal arteries (the blood vessels that bring blood to the brain) or clotting of the veins that surround the brain.In teenagers and young adults a sudden tear of an artery, called a dissection, blood clotting disorders, and use of illicit drug use are important considerations.

www.educatehealth.ca13What should done if someone might be having a strokeAn acute stroke is an emergency situation where time plays a crucial role in deciding which treatment should be given. Be familiar with and recognize the symptoms of stroke.Call 911 immediately. Where available patients may be transported to a stroke centre where specially trained stroke teams may be available to assist with managing acute stroke.www.educatehealth.ca14What can be done to treat an acute ischemic (non-bleeding) strokeThe clot busting drug tissue plasminogen activator (tPA) has been shown to beneficial in dissolving the clots blocking the blood vessels within the brain.tPA has to be given within 4.5hrs from the start of the symptoms.There is ~ 6% risk of causing a bleed in the brain with tPA, but studies show that at three months there is no difference in the amount who die after receiving tPA compared to those who do not get tPA. The main difference though is that more people recover with tPA use.www.educatehealth.ca15What can be done to treat an acute hemorrhagic (bleeding) strokeHemorrhages carry a higher risk of disability and death compared to non-bleeding stroke.tPA cannot be used for this condition. If the bleeding is found to be due to an aneurysm, in many cases the aneurysm can be closed off to stop recurrent bleeding.Some patients have bleeding around the brain that may be amenable to surgical removal of the clot.However, for bleeding within the brain tissue itself, i.e. not due to aneurysms, there is no specific treatment. Attention is placed on controlling blood pressure and general medical care. www.educatehealth.ca16How are stroke patients investigated and managed after the acute event ?Patients are usually admitted to a hospital for further investigations to determine what might have caused the stroke. Investigations might include: CT or MRI scan of the brain, an ultrasound of the carotid blood vessels in the neck, and an ECG or heart monitor to assess for irregular heart beat (atrial fibrillation). A cardiac ECHO (ultrasound) might be helpful in select cases.Studies show that management of patients on stroke units may help to reduce stroke recurrence and improve outcome.Rehabilitation may help with recovery, however, sometimes the stroke is so large and the disability so severe that rehabilitation is futile.www.educatehealth.ca17How can recurrence of ischemic (non-bleeding) stroke be prevented ?For patients with non bleeding stroke in whom narrowing of the carotid blood vessels in the neck is thought to be the cause of the stroke, these vessels can be operated on to open them up. This has been shown to reduce recurrent stroke.If atrial fibrillation is thought to be the cause of the stroke, patients are treated with anti-coagulant (blood thinning) drugs to reduce clots being formed in the heart.If a cause is not found after investigations then patients are usually treated with antiplatelet drugs (e.g. aspirin).All risk factors need to be addressed control and treat blood pressure, diabetes and cholesterol. Stop smoking and lose weight. www.educatehealth.ca18How can recurrence of hemorrhagic (bleeding) stroke be prevented ?For patients with aneurysm rupture these can be closed off with endovascular therapy (a small tube called a catheter is placed into the artery and extended through into the brain to the aneurysm. Small coils can then be placed within the aneurysm to seal it off. Aspirin and other blood thinning drugs are not usually used after a bleed in the brain unless there is some other special medical reason to do so.All risk factors need to be addressed, i.e. lifestyle modification, especially blood pressure control.www.educatehealth.ca19How can the risk of stroke be lowered?Be proactive:Know (record) and control your blood pressure if elevated (lose weight, decrease salt in take, be compliant with prescribed medications)Atrial fibrillation: Comply with blood thinning medication if prescribedLower cholesterol (diet, exercise, medication)Control diabetesModify lifestyleStop smoking Lose weight Reduce alcohol consumptionAvoid illicit drug useExerciseControl stress

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