Stroke is the 4th leading cause of death in the US, with one person dying every 4 minutes as a result. Approximately 800,000 people have a stroke each year; about one every 4 seconds. Only heart disease, cancer and chronic lower respiratory diseases are more deadly.
Strokes occur due to problems with the blood supply to the brain; either the blood supply is blocked or a blood vessel within the brain ruptures. A stroke is a medical emergency, and treatment must be sought as quickly as possible.
There are three main kinds of stroke; ischemic strokes, hemorrhagic strokes and transient ischemic attacks (TIAs), also referred to as mini-strokes.
Here are some key points about stroke:
During a stroke, the brain does not receive enough oxygen or nutrients, causing brain cells to die.
There are three main kinds of stroke: ischemic strokes, hemorrhagic strokes and transient ischemic attacks.
Ischemic strokes are caused by a narrowing or blocking of arteries to the brain.
Hemorrhagic strokes are caused by blood vessels in and around the brain bursting or leaking.
Strokes need to be diagnosed and treated as quickly as possible in order to minimize brain damage.
Remembering the F.A.S.T. acronym can help with recognizing the onset of stroke.
Treatment depends on the type of stroke.
Ischemic strokes can be treated with 'clot-busting' drugs.
Hemorrhagic strokes can be treated with surgery to repair or block blood vessel weaknesses.
The most effective way to prevent strokes is through maintaining a healthy lifestyle.
Stroke occurs when the supply of blood to the brain is either interrupted or reduced. When this happens, the brain does not get enough oxygen or nutrients which cause brain cells to die.
Strokes occur due to problems with the blood supply to the brain; either the blood supply is blocked or a blood vessel within the brain ruptures.
There are three main kinds of stroke; ischemic, hemorrhagic and TIA.
In the US, approximately 40% of stroke deaths are in males, with 60% in females. According to the American Heart Association (AHA), in 2006, the stroke death rates per 100,000 populations could be split into specific social groups at 41.7% for white males, 41.1% for white females, 67.7% for black males and 57.0% for black females.
Stroke is also more likely to affect people if they are overweight, aged 55 or older, have a personal or family history of stroke, do not exercise much, drink heavily or use illicit drugs.
The different forms of stroke have different specific causes.
Ischemic strokes are the most common form of stroke, with around 85% of strokes being of this type. They are caused by the arteries that connect to the brain becoming blocked or narrowed, resulting in ischemia - severely reduced blood flow.
These blockages are often caused by blood clots, which can form either in the arteries connecting to the brain, or further away before being swept through the bloodstream and into narrower arteries within the brain. Clots can be caused by fatty deposits within the arteries called plaque.
Hypertension can lead to blood vessel ruptures and hemorrhagic strokes.
Hemorrhagic strokes are caused by arteries in the brain either leaking blood or bursting open. The hemorrhaged blood puts pressure on brain cells and damages them. Blood vessels can burst or spill blood in the middle of the brain or near the surface of the brain, sending blood into the space between the brain and the skull. The ruptures can be caused by conditions such as hypertension, trauma, blood-thinning medications and aneurysms (weaknesses in blood vessel walls).
Transient Ischemic Attack (TIA):
TIAs are different from the aforementioned kinds of stroke because the flow of blood to the brain is only disrupted temporarily for a short time. They are similar to ischemic strokes in that they are often caused by blood clots or other debris.
TIAs should be regarded as medical emergencies just like the other kinds of stroke, even if the blockage of the artery is temporary. They serve as warning signs for future strokes and indicate that there is a partially blocked artery or clot source in the heart.
According to the Centers for Disease Control and Prevention (CDC), over a third of people who experience a TIA go on to have a major stroke within a year if they have not received any treatment. Between 10-15% will have a major stroke within 3 months.
Signs and Symptoms:
Strokes occur quickly, and as such their symptoms often appear suddenly without warning. The main symptoms are as follows:
Confusion, including trouble with speaking and understanding.
Headache, possibly with altered consciousness or vomiting.
Numbness of the face, arm or leg, particularly on one side of the body.
Trouble with seeing, in one or both eyes.
Trouble with walking, including dizziness and lack of co-ordination.
Strokes can lead to long-term problems. Depending on how quickly it is diagnosed and treated, the patient can experience temporary or permanent disabilities in the aftermath of a stroke. In addition to the problems listed above continuing, patients may also experience the following:
Bladder or bowel control problems
Pain in the hands and feet that gets worse with movement and temperature changes
Paralysis or weakness on one or both sides of the body
Trouble controlling or expressing emotions.
Tests and diagnosis:
Strokes occur quickly, so that often a stroke diagnosis will have to be made before an individual can be seen by a doctor. The acronym FAST is a way to remember the signs of stroke, and can help toward identifying the onset of stroke in someone:
Face drooping: if the person tries to smile does one side of the face droop?
Arm weakness: if the person tries to raise both their arms does one arm drift downward?
Speech difficulty: if the person tries to repeat a simple phrase is their speech slurred or strange?
Time to call 911: if any of these signs are observed, contact the emergency services.
It is important that strokes are diagnosed as quickly as possible. The quicker that treatment can be administered, the less damage that will be done to the brain. In order for a stroke patient to get the best diagnosis and treatment possible, they will need to be treated at a hospital within 3 hours of their symptoms first appearing.
Both ischemic strokes and hemorrhagic strokes require different kinds of treatment. Unfortunately, it is only possible to be sure of what type of stroke someone has had by giving them a brain scan in a hospital environment.
There are several different types of diagnostic tests that doctors can use in order to pin down precisely what type of stroke has been experienced:
CT scans of the brain are one of the only ways to diagnose what type of stroke a person has had.
Physical examination: a doctor will ask about the patient's symptoms and medical history. They may check blood pressure, listen to the carotid arteries in the neck and examine the blood vessels at the back of the eyes, all to check for indications of clotting
Blood tests: a doctor may perform blood tests in order to find out how quickly the patient's blood clots, what the levels of chemicals within it are like and whether or not the patient has an infection
CT scan: a series of X-rays that can show hemorrhages, strokes, tumors and other conditions within the brain
MRI scan: radio waves and magnets create an image of the brain to detect damaged brain tissue
Carotid ultrasound: an ultrasound scan to check the blood flow of the carotid arteries and to see if there is any plaque present
Cerebral angiogram: dyes are injected into the brain's blood vessels to make them visible under X-ray, in order to give a detailed view of the brain and neck arteries
Echocardiogram: a detailed image of the heart is created to check for any sources of clots that could have traveled to the brain to cause a stroke.
Treatment and Prevention:
As the two main different kinds of stroke, ischemic and hemorrhagic, are caused by different factors, both require different forms of treatment. It is particularly important that the type of stroke is diagnosed quickly, not just to reduce the damage done to the brain but because treatment for one kind of stroke may be harmful to someone who has had a different kind.
Ischemic strokes are caused by arteries being blocked or narrowed and so treatment focuses on restoring an adequate flow of blood to the brain.
Treatment can begin with drugs to break down clots and prevent further ones from forming. Aspirin can be given, as can an injection of a tissue plasminogen activator (TPA). TPA is very effective at dissolving clots but needs to be injected within 4.5 hours of stroke symptoms manifesting themselves.
Surgeons are able to remove plaque and any other obstructions from the carotid artery through surgery.
Emergency procedures include administering TPA via catheter directly into an artery in the brain or using a catheter to physically remove the clot from its obstructive position. Recent studies have cast doubt as to the effectiveness of these methods, and so research is still ongoing as to how beneficial these procedures are.
There are other procedures that can be carried out to decrease the risk of future strokes or TIAs. A carotid endarterectomy involves a surgeon opening the carotid artery and removing any plaque that might be blocking it.
Alternatively, an angioplasty involves a surgeon inflating a small balloon in a narrowed artery via catheter and then inserting a stent (a mesh tube) into the opening in order to prevent the artery from narrowing again.
Hemorrhagic strokes are caused by bleeding into the brain and so treatment focuses on controlling the bleeding and reducing the pressure on the brain that it is causing.
Treatment can begin with drugs being given to reduce the pressure in the brain, overall blood pressure, prevent seizures and prevent sudden constrictions of blood vessels. If the patient is taking anti-coagulant or anti-platelet medication like Warfarin or Clopidogrel, they can be given drugs or blood transfusions to counter the medication's effects.
Surgery can be used to repair any problems with blood vessels that have led or could lead to hemorrhagic strokes. Surgeons can place small clamps at the base of aneurysms or fill them with detachable coils to stop blood flow to them and prevent rupture.
Surgery can also be used to remove small arteriovenous malformations (AVMs) if they are not too big and not too deep within the brain. AVMs are tangled connections between arteries and veins that are weaker and burst more easily than other normal blood vessels.
Strokes are life-changing events that can affect a person both physically and emotionally. As such, certain rehabilitating activities may need to be carried out in order for a person who has experienced a stroke to fully recover.
Speech therapy can help with problems producing or understanding speech. Practice, relaxation and changing communication style, using gestures or different tones for example, all help
Physical therapy helps with relearning movement and co-ordination. It is important to get out and about, even if it is difficult at first
Occupational therapy helps to improve the carrying out of routine daily activities, such as bathing, cooking, dressing, eating, reading and writing
Joining a support group can help with common mental health problems such as depression that can occur after a stroke. Many find it useful to share common experiences and exchange information
Support from friends and family is also useful and can provide comfort. Letting friends and family know what can be done to help is very important.
The best way to prevent a stroke is to address the underlying causes. This is best done by living healthily. Here is a list of simple measures that can be followed:
Avoid illicit drugs
Eat a diet rich in fruit and vegetables and low in cholesterol and saturated fat
Keep blood pressure under control
Keep diabetes under control
Maintain a healthy weight
Moderate alcohol consumption (or quit drinking)
Treat obstructive sleep apnea (if present).
As well as these lifestyle changes, a health care provider can help to reduce the risk of future strokes through prescribing anti-coagulant and anti-platelet medication. In addition to this, the arterial surgery previously mentioned can also be used to lower the risk of repeat strokes.
Recent developments on stroke treatment and prevention from MNT news
Controlling blood pressure after stroke 'halves risk of recurrence'
Around 750,000 Americans have a stroke every year. Of these, 5-14% will have a second stroke within 12 months. But new research suggests that if blood pressure is consistently controlled after an initial stroke, the risk of a second one could be reduced by more than 50%.
Each 15-minute delay steals 1 month of healthy life for stroke sufferers
When it comes to getting treatment for stroke, every minute counts. This is the conclusion of a study published in the American Heart Association's journal Stroke, which shows that for every minute treatment is accelerated, the patient gains another 1.8 days of healthy life.
Potassium-rich foods could lower stroke risk in older women
Researchers have found that older women whose diets involve potassium-rich foods may be at a reduced risk of stroke and have a greater life expectancy than women consuming less potassium-rich foods.
Copyright: Medical News Today