Family Health Magazine - FAMILY MEDICINE
Recognize and treat a ‘brain attack’ quickly
Your brain is the most complex organ in your body. It consists of over 100 billion specialized nerve cells called neurons. These brain cells control everything we do, from speaking to walking to breathing. Brain functions include:
- movement - motor functions and coordination of movement
- perception - how we interpret information from our senses
- sensation - such as touch
- vision - how we see
- cognition - thinking, remembering, understanding, planning, reasoning and problem-solving
- communication - speaking and understanding
- personality - including emotions and behaviors.
Stroke is a sudden loss of brain function caused by an interruption in blood flow to the brain. The brain needs a steady supply of oxygen and blood to function properly. Without this, brain cells cannot do their job.
A stroke or ‘brain attack’ occurs. Neurons cannot duplicate or repair themselves.
Very few Canadians know the symptoms of stroke.
Do you? Learning them and knowing what to do when they occur could save your life.
For more information, visit www.heartandstroke.ca
Recognizing stroke symptoms
The onset of stroke symptoms is very fast. This in itself is a key feature of stroke. The most common symptoms are highlighted in the graphic at left, and include:
- sudden weakness, numbness or paralysis of the face, arm, or leg, especially on one side of the body
- sudden difficulty speaking or understanding simple statements
- sudden blurred or reduced vision in one or both eyes
- sudden unexplainable and intense headache, often described as ‘the worst headache ever’
- sudden dizziness, loss of balance or loss of coordination, especially when combined with another symptom.
Other important but less common symptoms include:
- sudden nausea, fever, and vomiting that are different from a viral illness or flu (onset in minutes or hours, not days)
- brief loss of or reduced consciousness (fainting, confusion, convulsions or coma).
These symptoms are more commonly associated with hemorrhagic stroke events than ischemic ones.
Never ignore stroke symptoms!
- Only a doctor can tell for sure if you are having a stroke or TIA (Transient Ischomic Attack or ‘mini-stroke’) see definition BELOW.
- If you are having a stroke, emergency medical treatment could save your life and greatly improve your chances for successful rehabilitation and recovery.
- If you are having a TIA your doctor will evaluate and treat the causes. Following your doctor’s advice on medication and treatment can reduce your risk of having a stroke.
- For every minute that brain cells have no oxygen during a stroke, brain damage occurs.
- Several new drugs and treatments may stop – and even reverse – brain damage when used immediately during or shortly after a stroke. ‘Clot-busting’ drugs are only effective for a limited time (4½ hours) after the start of stroke symptoms. Getting medical help immediately is essential.
ANATOMY OF A STROKE
Each stroke is different. Recovery will depend on which parts of the brain were damaged by the stroke as well as the size of the area damaged. A person’s health before the stroke also affects recovery.
The human brain is divided into sides or hemispheres (left and right), and regions within each hemisphere (lobes) that control various motor (movement) and sensory functions. If the stroke damages a specific region, the functions it controls can be affected. This causes symptoms like paralysis (loss of movement), difficulty speaking, or loss of coordination.
Effects of left hemisphere strokes include:
- weakness or paralysis on the right side of the body
- trouble reading, talking, thinking or doing math
- behaviour that is slower and more cautious than usual
- trouble learning or remembering new information
- frequent instructions and feedback is needed to finish tasks.
- Effects of right hemisphere strokes include:
- weakness or paralysis on the left side of the body
- vision problems
- difficulty distinguishing distance, depth, between up and down or front and back, which makes it hard to pick up objects, button a shirt, or tie shoes
- problems understanding maps
- short-term memory issues – someone may be able to remember something that happened years ago, but not something that happened a few minutes ago
- ‘neglect’ - forgetting or ignoring objects or people on the left side; stroke survivors may even ignore their own left arms or legs
- judgment issues like acting impulsively or not realizing one’s limitations.
For every minute of delay in
treating a stroke, almost two million
brain cells are lost. For each hour in which treatment does not occur, the brain losesas many neurons as it does in more than three years of normal aging.
Are you at risk of stroke?
Take the Heart & Stroke Risk Assessment:
Medical and lifestyle reasons can make a person more likely to have a stroke. These are called stroke risk factors. Some are beyond control, including the following.
- Age – while stroke can occur at any age, most occur over age 65.
- Sex – before menopause, women have a lower risk than men, but more women die from stroke than men.
- Ethnicity – risk is increased for those of Aboriginal, African or South Asian descent because of higher rates of high blood pressure and diabetes.
- Family history of stroke – if a parent or sibling had a stroke before age 65.
- Prior stroke or TIA – increases the risk of another stroke or TIA. Risk of stroke is greatest immediately after the stroke or TIA, and stays high for five years. Overall, 30 per cent of stroke survivors have a second stroke.
With medical attention and lifestyle changes, you can lower your risk of a first stroke or the chances of having another.
For the top 10 risk factors, see table below.
|The top 10 risk factors for stroke and how to manage them
|Blood pressure (BP): high BP (hypertension) is the number one risk factor for stroke. Normal BP should be less than 120/80. You may not feel high blood pressure, but serious side effects can appear if it remains consistently high. Talk to your doctor about the right medications for you. It may take more than one to adequately control your high blood pressure.
- Check BP regularly, at least every two years.
- Take medications as prescribed.
- Eat a healthy diet.
- Consume alcohol in moderation.
- Reduce your stress.
Cholesterol: Dyslipidemia, known as high cholesterol, may also cause a stroke. Cholesterol deposits build up inside arteries, blocking them and causing increased blood pressure and other problems.
Regular blood levels of:
- Low density lipoproteins (LDL or ‘lousy’ cholesterol) should be less than 2 mmol/L.
- High density lipoproteins (HDL or ‘healthy’ cholesterol) should be greater than 1.3 mmol/L for women, and greater than or equal to 1.0 mmol/L for men.
- Total cholesterol to HDL ratio should be less than 4 mmol/L, and
- Triglycerides (another common fatty acid) should be less than 1.5 mmol/L.
- See your GP for regular blood work.
- Eat a healthy diet.
- Exercise regularly.
- Moderate alcohol consumption.
- Take your medication as prescribed.
|Diabetes: Poorly controlled diabetes damages small blood vessels in your brain. Normal fasting blood glucose should be between 4 and 7 mmol/L. Serum hemoglobin (Hgb) A1C is a good indicator of how well you are managing your blood glucose. It should be less than or equal to 7 per cent. For many people with diabetes, the goal is to keep your level at or below 6.5 to 7 per cent.
- Eat a healthy diet.
- Exercise regularly.
- Check your blood glucose and take your medication as prescribed.
|Atrial fibrillation: In atrial fibrillation (AF), the heart’s upper chambers (the atria) quiver instead of beating effectively, causing blood pooling and clots. AF increases stroke risk four to six times compared to those without AF.
- Take your blood thinner as prescribed.
- Have frequent blood work done.
- See your doctor regularly.
|Tobacco use: Tobacco damages blood vessels. Quitting smoking reduces your risk of stroke by half after two years of being smoke-free.
- Find a smoking cessation program that is right for you.
|Diet: Keep your total daily sodium intake to less than 1500 milligrams. Read food labels when purchasing processed food. Do not add salt to food. Use other flavor-enhancers, like herbs and spices. Eat a varied diet of fruits, vegetables, whole grains and lean meats.
- Balance calories with exercise.
- Take in less than 1500 mg of sodium daily.
- Make healthy choices when eating.
- Shop the perimeter of the store, where the fresh groceries are located.
|Alcohol: Heavy alcohol use increases your risk of stroke in a number of ways. Drink in moderation – less than 14 drinks per week for men, and less than nine per week for women.
- Consume alcohol in moderation.
- Avoid binge drinking.
|Obesity: Extra weight, especially around the abdomen, increases your risk of stroke and heart attack. A healthy waist circumference is 102 centimetres (40 inches) or less for men, and 88 cm (35 inches) or less for women. Talk to a dietitian or other health care provider about a diet and exercise plan to help you control your weight.
- Maintain a healthy weight.
- Balance a healthy diet with exercise.
- Consult a dietitian, especially if you have special considerations like diabetes or high cholesterol.
|Physical activity: Being physically active reduces your risk of heart attack and stroke, makes your heart stronger, helps to control weight and blood pressure, and can even improve your mood.
- Check with your doctor before starting.
- Get at least 1½ hours of moderate exercise per week.
- Try a variety of activities.
- Look for simple ways to become more active.
Metabolic syndrome: This group of risk factors increases your risk for stroke. If you have at least three of the five conditions listed below, you have metabolic syndrome.
- abdominal obesity
- having or being on medication for high triglycerides
- low HDL
- having or being on medication for high blood pressure
- having high blood glucose, or being on diabetes medication.
This puts you at increased risk for stroke and heart disease.
- Make healthy lifestyle changes, as listed above.
Drugs used in stroke prevention
Several medications and categories of medication may be used to protect against first or recurring stroke or TIA. These include the following.
- Anticoagulant agents - These medications work by thinning the blood, making it flow more easily through narrowed blood vessels and reducing the risk of clots.
- Antiplatelet agents - the most commonly recommended antiplatelet agents for secondary stroke prevention in North America and Europe are acetylsalicylic acid (ASA), clopidogrel, and the combination of ASA and extended-release dipyridamole.
- Antithrombotic agents - these are blood thinner medications typically used to treat atrial fibrillation. They include warfarin (also known as Coumadin®), or one of the newer recently approved drugs such as dabigatran, rivaroxaban and apixaban.
- Statin drugs - these are medications used to lower cholesterol. Anyone who has had an ischemic stroke or TIA needs an assessment of serum lipid levels. If they are high, they should be strictly controlled through diet, exercise and medication. These medications may prevent ischemic stroke and TIA, but do not affect intracerebral hemorrhage.
Your doctor must know what other medications you are taking when prescribing one of these anti-stroke drugs. Some medications, such as anti-inflammatory drugs, can cause serious medical problems when combined with anti-stroke drugs.
Many people are interested in alternative medicine. However, there is no evidence that vitamins or herbal remedies provide real protection against stroke or TIA. If you are interested in these medicines, ask your doctor for more information.
Stroke is a life-threatening event. Still, quick medical attention can minimize the effects. Talk with your doctor about your risk for stroke. You can reduce your risk factors by making healthy choices and living an active lifestyle. Know the signs and symptoms of stroke. Get medical attention immediately if you suspect stroke in yourself or someone else.
Types of stroke
Ischemic stroke – This is a stroke caused by blockages in blood flow to the brain. Blood clots, formed in the heart or elsewhere in the body, can create one type of blockage. Another is the build-up of plaque or other fatty deposits in an artery that make the artery harden and clog. Chunks of this build-up can break off and float in the blood, eventually blocking an artery. Most strokes (about 80 per cent) are ischemic in nature.
‘Mini-stroke’ or transient ischemic attack (TIA) – This type of stroke is caused by a temporary interruption in blood flow to the brain. Typically symptoms go away within minutes or hours. Some people do not even know they have had a TIA. However, this important warning event puts a person at risk of a bigger and potentially more serious full-blown stroke. The risk of stroke following TIA is high: 10 to 20 per cent within 90 days. Half of these actually occur within the first two days after the TIA. Someone who has had one or more TIAs is almost 10 times more likely to have a stroke than someone of the same age and sex who has not had a TIA.
Hemorrhagic stroke – With this stroke, a blood vessel in the brain suddenly breaks, leading to uncontrolled bleeding into the brain tissue. About 20 per cent of all strokes are hemorrhagic. As bleeding into the brain interrupts normal blood flow, brain cells die. If a blood vessel located between the brain and the skull ruptures, it can bleed into the brain. This is called a subarachnoid hemorrhage. It is usually related to a structural problem with a blood vessel.
A weakened area on the wall of a blood vessel (called an aneurysm) fills with blood (like a balloon) and bulges out. Another kind of bleeding in the brain happens when an artery deep within the brain itself ruptures. This is called an intracerebral hemorrhage. High blood pressure or trauma can make a bulge rupture, resulting in uncontrolled bleeding into the brain.
Brain stem strokes - This type of stroke is uncommon. The brain stem is the area at the very base of the brain, right above the spinal cord. When a stroke occurs in the brain stem, there can be problems with:
- breathing and heart function
- body temperature control
- balance and coordination
- weakness or paralysis of the arms and legs on both sides of the body
- chewing, swallowing and speaking
Strokes in the cerebellum - The cerebellum is located at the lower back of the brain. Although strokes are less common in the cerebellum, the effects can be severe. Four common effects of strokes in the cerebellum include:
- inability to walk and problems with coordination and balance (called ataxia)
- nausea and vomiting.
Tests used to diagnose stroke
Stroke is an emergency. If you have any stroke symptoms or recognize them in someone else, call 911 immediately!
If a stroke or TIA is suspected, the family doctor or an emergency room doctor will do a physical examination and tests of blood and urine. One or more tests can also give a picture of what is happening in the brain, blood vessels or heart.
On first arriving in the emergency room, taking blood pressure readings and listening to the heart and lungs allows doctors to assess breathing, airway and circulation. Neurological (nervous system) status will be checked to see if there is weakness or loss of function. Tests can determine the severity, type and extent of the stroke, and may include the following.
All patients with suspected acute stroke or TIA are assessed using brain imaging.
- Computerized axial tomography (CAT scan or CT scan) - The CT scanner is a large device that takes a series of X-rays of the head. These images show whether a stroke was caused by a blood clot (ischemic stroke) or uncontrolled bleeding (hemorrhagic stroke). The images also help rule out other brain processes that can mimic the effects of a stroke. If the CT scan confirms that the stroke was caused by a blood clot, the tPA drug that breaks up or dissolves clots can be given. This may reduce the effects of stroke.
- Magnetic resonance imaging (MRI) - An MRI is a large imaging device that sits in its own room. It uses a harmless magnetic field and radio waves to get clear, sharp pictures of the inside of the brain. MRI is used to detect bleeding in the brain, tumors or stroke. It is also an excellent device for detecting smaller strokes or strokes in the back of the brain, which other imaging devices can miss. MRI images show even more detail than CT scans, and can be viewed in 3-D on a computer screen.
- Vascular imaging - This should be done on the carotid and vertebral arteries in the neck within 24 hours of a TIA or ischemic stroke. This imaging can be done using duplex ultrasonography, magnetic resonance angiography (MRA), CT angiography (CTA), or catheter angiography (see details below). Ideally, MRA or CTA is done at the time of the initial MRI or CT scan. However, if doctors do not believe blood flow can be restored to the brain, the tests will not be performed.
- Carotid ultrasound - This ultrasound uses sound waves to examine blood flow in the carotid arteries. These arteries, which carry blood to the brain, are located on both sides of the neck. Sound waves are delivered through a transducer (a unit that directs the sound waves) placed over the carotid artery. The sound waves appear as an image on a monitor. This kind of ultrasound can help the doctor find any narrowing or blockage of the carotid arteries.
- Magnetic Resonance Angiogram (MRA) - This imaging technique is used to detect any blocking or narrowing of the arteries in the neck and brain. Like an MRI, an MRA uses a strong magnetic field and radio waves to take pictures of the blood vessels. It produces 3-D images of these specific veins and arteries. This allows doctors to get very detailed information about a stroke.
- Cerebral angiography - Also known as arteriography, this exam is used to detect blockages of arteries and veins. Pictures are taken of the blood flowing through the arteries in the neck and brain. A dye that shows up on X-rays is injected into an artery. Next, a series of rapid-image X-rays are taken as the dye travels through the arteries. These X-rays show how the blood is flowing, and the size and location of any blockages. This procedure is also sometimes used to help identify problems or malformations in blood vessels.
- Electrocardiogram (ECG or EKG). This test checks how the heart is functioning by measuring the electrical activity. With each heartbeat, an electrical impulse (or wave) travels through the heart. This wave makes the muscle squeeze and pump blood from the heart. By measuring how long an electrical wave takes to pass through the heart, the cardiologist (heart specialist) can determine if the electrical activity is normal, fast or irregular. Measuring the amount of electrical activity passing through the heart helps the cardiologist to tell if the heart is enlarged or overworked. An ECG is used to:
- detect abnormal heart rhythms that may have caused blood clots to form.
- detect heart problems (including a recent or ongoing heart attack), abnormal heart rhythms (arrhythmias), coronary artery blockage, areas of damaged heart muscle (from a prior heart attack), enlargement of the heart, and inflammation of the sac surrounding the heart (pericarditis).
- detect non-heart conditions like electrolyte imbalances and lung diseases
- monitor recovery from a heart attack, progression of heart disease, or the effectiveness of certain heart medications or a pacemaker
- rule out hidden heart disease in patients about to have surgery.
- Holter monitor - Holter monitoring is usually used to diagnose heart rhythm disturbances, specifically the cause of palpitations (abnormal heartbeat) or dizziness. The Holter monitor is a small recording device. It is connected to small metal disks called electrodes that are placed on the chest to read heart rate and rhythm over a 24-hour period or longer. The heart’s rhythm is transmitted and recorded on a tape, then played back into a computer so it can be analyzed to find out what is causing the arrhythmia. Some monitors let the wearer push a record button to capture a rhythm as soon as any symptoms are felt.
- Event monitoring - Like a Holter monitor, an event monitor also uses a recording device to monitor the heart, although the device is smaller. One is the size of a beeper, while another is worn like a wristwatch. Unlike the Holter, it does not continuously monitor the heart over a 24-hour period. It starts recording when the wearer feels symptoms and starts the monitor. When symptoms of an arrhythmia are felt, the wearer phones a monitoring station so that a record can be made. If the wearer cannot get to a phone, the information can be saved in the event monitor and sent later to a monitoring station.
- Echocardiogram - This uses sound waves (ultrasound) to create a picture of the heart. The recorded waves show the shape, texture and movement of the heart valves, as well as the size of the heart chambers and how well they are working. This test may be done to determine whether a stroke was caused by a heart condition. It can also help determine if there is a risk of blood clots forming in the heart.
- Transesophageal echocardiogram (TEE) is a special type of echocardiogram. It is usually done when the doctor wants to look more closely at the heart to see if it is producing blood clots. Like an echocardiogram, the TEE uses high-frequency sound waves (ultrasound) to examine the structures of the heart. A transducer (a unit that directs the sound waves) is placed in the esophagus (the pipe that connects the mouth to the stomach). The esophagus is close to the heart, so images from a TEE can give very clear pictures of the heart and its structures.
While effort is made to reflect accepted medical knowledge and practice, articles in Family Health Online should not be relied upon for the treatment or management of any specified medical problem or concern and Family Health accepts no liability for reliance on the articles. For proper diagnosis and care, you should always consult your family physician promptly. © Copyright 2015, Family Health Magazine, a special publication of the Edmonton Journal, a division of Postmedia Network Inc., 10006 - 101 Street, Edmonton, AB T5J 0S1 [FM_FHc13]