Every 53 seconds, someone in the United States will suffer a stroke1. Strokes are the third largest cause of death, ranking behind 'diseases of the heart' and all forms of cancer, and is the leading cause of serious, long-term disability around the world. According to studies, there are about 600,000 stroke victims per year in the United States (500,000 of which are new stroke victims), while there are 100,000 new stroke victims per year in the UK2. However, more than 4,400,000 stroke survivors are alive today. Strokes aren't necessarily fatal - many people live full, healthy lives after suffering one. Yet some people are left permanently disabled afterwards, never returning to an optimum level of function. It is important to study the nature of a stroke before examining the after effects it might have on one's body.
What is a Stroke?
A stroke (also called a 'brain attack') is an injury to the brain caused by an obstruction to, or rupture of, its blood supply. Without blood, the brain is robbed of oxygen and nutrients, and without these essential nutrients, brain cells begin to die within four minutes.
There are several types of stroke, each one very different from the other:
An Ischemic stroke is caused by blockage of a blood vessel to the brain, perhaps due to high cholesterol, arterial blockage or blood clot. This is the more common type of stroke. The two types of ischemic stroke are:
- Thrombosis - A gradual narrowing and eventual blockage of a brain or neck artery.
- Embolism - A blockage of a brain or neck artery by a clot.
- A Hemorrhagic stroke is caused by a rupture of a blood vessel in the brain. This may be attributed to genetics and/or age. This type of stroke is more likely to be fatal.
- Transient ischemic attacks or TIAs are a sort of 'mini stroke' which produce stroke-like symptoms but no lasting damage. They are strong predictors of future stroke.
While the effects of these types of strokes on the body may be similar, the causes and treatments of this illness are diverse.
Risk Factors Attributed to Strokes
The risk factors associated with strokes are numerous. These factors include:
- Increasing age (wspecially over age 60)
- Male sex
- Heredity (family history) and race
- Prior stroke or TIA
- High blood pressure
- Cigarette smoking
- Diabetes mellitus
- Carotid artery disease
- Heart disease
- High red blood cell count
- Geographic location (due to the types of fatty foods and genetic/racial patterns found in some geographic locations)
- Season and climate (eg, very hot weather)
- Socio-economic factors
- Excessive alcohol intake
- Certain kinds of drug abuse (eg, cocaine, methamphetamines)
- Certain forms of prescription medication (eg, birth control pills)
Usually, one or more of these risk factors may be associated with a greater factor. For example, a person who is diabetic might also be overweight and suffering from heart disease as a result of the diabetes, yet a stroke is a risk in all of those factors.
Factors that initially increase the risk of heart disease, and therefore also increase the risk of stroke, are called secondary factors. These include:
- High blood cholesterol and lipid intake
- High blood pressure
- Physical inactivity
- Cigarette smoking
- Obesity (weighing more than one's ideal body weight)
By alleviating as many of these risk factors as possible and trying to keep overall, general good health, one will greatly decrease one's chances of suffering a stroke.
Women and Strokes
Statistically3, women make up 52% of all stroke fatalities. Over an entire lifetime, about 16% of women will die of a stroke, whereas only 8% of men will die of a stroke. This is probably due to the older age of women at the time of the stroke's occurrence and also due to their longer life expectancy. There has been, unfortunately, little comparative research on women's heart and cardiovascular disease, although it has been shown that women may actually have a greater risk of suffering from these illnesses than men. Pregnancy and the use of some oral contraceptives also increase a woman's chance of suffering a stroke.
Stroke Warning Signs
Some of the classic stroke warning signs are:
Sudden numbness or weakness of face, arm or leg, especially on one side of the body.
Sudden confusion, trouble speaking or understanding spoken words.
Sudden trouble seeing in one or both eyes.
Sudden trouble walking, dizziness, loss of balance or co-ordination.
Sudden, severe headache with no known cause.
If any of the above signs are temporary and only last a few minutes, one might be suffering from a TIA These usually last about 30 minutes, then disappear with no long-term side affects or lasting damage. However, a person who has suffered one or more TIAs is almost 10 times more likely to have a stroke than someone of the same age and sex who hasn't. A TIA tends to be the precursor to a full-blown stroke.
If anyone is experiencing one or more of these symptoms, they should see a health care provider immediately for treatment.
How a doctor treats a stroke depends on many factors. The type of stroke, age of the patient, severity of the stroke and general overall health of the patient are all factors that might determine the types of treatment the patient requires.
For a hemorrhagic stroke, it is most important to first correct the cause of the hemorrhage, then to protect the brain from further damage. Often times, an aneurysm, or a swelling or ballooning of a section of an artery, can burst, causing a hemorrhage. Hemorrhages and aneurysms can both be treated through a procedure in which a surgeon clamps at its base and then removes the defective blood vessel, replacing it with a graft (a tube made of polyester or Teflon fabric) or a stent graft (a similar tube which is reinforced with wire mesh giving it more strength and structure). Another method of treating hemorrhages and aneurysms is with a technique known as catheter coagulation. Here, the surgeon uses a catheter containing a metal coil, which is then passed through the defective blood vessel, causing it to clot and seal off the hemorrhage on its own. Eventually, the clot may become harmless scar tissue. Aneurysms can also be treated with a radiocoagulation technique. This technique uses external beam radiation in conjunction with a radiation-sensitive clotting agent injected into the blood. A highly focused beam of energy can then be directed to the centre of the aneurysm to minimise injury to surrounding tissues.
Because a hemorrhage may cause blood to pool in the brain, and because the brain is confined in the skull, this pooled blood (known as a hematoma) can sometimes dangerously increase pressure on the brain and damage delicate tissue. Increased pressure can also impair circulation to the uninjured area of your brain, causing further brain damage. Limiting fluids and giving diuretic drugs to minimise temporary swelling of brain tissue will typically correct this. Rarely, surgery is needed to drain clots of pooled blood from within the area of damaged brain tissue.
In the case of an ischemic stroke with thrombosis, a narrowing, or stenosis, of an artery is blocking the flow of blood to the brain. This form of stroke can be treated by dilating the stenosis, or by placing a small metal coil called a stent in the stenosis to keep it open. An operation called a carotid endarterectomy can also help relieve stenosis and blockage by removing plague and debris build-up in the carotid artery.
For an ischemic stroke with embolism, or clot blocking the flow of blood to the brain, the use of aspirin or an anticoagulant (or blood thinner) such as Ticlopidine may be given to prevent future clots, as well as to help establish normal blood flow to the brain. Also, the FDA4 recently approved the use of Tissue Plasminogen Activators (TPA) to treat ischemic strokes and embolisms within the first three hours of occurrence. TPA is one of several new drugs currently being researched with the ability to dissolve the blood clots that are responsible for causing many strokes. More research is being done on this drug to test its effectiveness with stroke patients, especially its ability to decrease the chance of TIAs after a major stroke.
Doctors and surgeons have several tools at their disposal to help in early identification of strokes. For instance, Magnetic Resonance Imaging (MRI) scanning is most sensitive for detecting an area of brain tissue damaged by an ischemic stroke. Computed Tomography(CT) imaging is most useful for identifying an area in the brain damaged by hemorrhage. An angiogram involves injecting dye through a catheter inserted into a blood vessel suspected of being blocked, aneurysmal, or which may have an arteriovenous malformation. X-rays of these vessels will then show impaired blood flow or blockage, if any.
Early treatment of a stroke greatly increases one's chance for recovery. The longer a stroke victim suffers from interrupted blood flow to the brain, the more brain damage is incurred.
Effects of a Stroke
Anoxia is a condition in which there is an absence of oxygen supply to an organ's tissues, although there is adequate blood flow to the tissue. Hypoxia is a condition in which there is a decrease of oxygen to the tissue in spite of adequate blood flow to the tissue. Anoxia and hypoxia, however, are often used interchangeably without regard to their specific meanings. They may both be used to describe a condition that occurs in the brain when there is a diminished supply of oxygen to brain tissue. Anoxia and hypoxia are the major causes of mental and physical disability suffered by stroke victims.
The effects of a stroke, both mental and physical, depend upon its severity. Some patients may suffer few or no side effects as a result of a stroke. Some patients may have a delayed reaction after suffering one, with symptoms appearing as the recovery process continues. And, as recovery proceeds, a variety of psychological and neurological abnormalities may appear, persist for a time, and then disappear. Mental changes such as dementia or a psychosis may occur. Mental confusion, personality regression, parietal lobe syndromes, amnesia, hallucinations, and memory loss may also take place.
A stroke in the brain's right hemisphere may cause paralysis and loss of vision or sensation only on the left side of the body. There may be difficulty in judging distance, size and rate of movement (spatial relationships). In addition, the stroke victim's behaviour may be quick and impulsive.
Left-brain injury incurs similar paralysis and loss of vision and sensation, but this time on the body's right side. Instead of having trouble with spatial relationships, there may be difficulty in speaking or understanding speech. Behaviour may be slow and cautious.
Recovering from a Stroke
Recovery depends wholly on the intensity of the stroke, the severity of the damage incurred, and the general health of the person in question. While most people see significant rehabilitative progress only six months after a stroke, some people may never fully recover. Physical therapy is essential for some patients in order to regain the strength and muscle control they may have lost because of the stroke. Other patients may need psychological treatment (counselling) to counter the effects of depression, which usually stem from a feeling of isolation experienced by many people upon developing a disability.
Continued patient care also includes regular health check-ups in addition to maintaining a healthy lifestyle. If a stroke patient works to remove certain avoidable risk factors from their lifestyle, the chances of suffering another stroke are greatly diminished.
Not all strokes take place due to an event in the brain. The arteries in the neck may become clogged or narrowed, robbing the brain of its blood supply. A physical examination is a chance for your doctor to check your blood pressure and listen to your heart for signs of valve or rhythm problems. Using a stethoscope to listen to your carotid arteries, your doctor can detect a noise, called a 'bruit', made by turbulent blood flow through a narrowed artery.
Individuals over the age of 60, smokers, and those who have heart disease or high blood cholesterol may benefit from a Doppler Ultrasound Screening (outside the body) that assesses stroke risk by measuring arterial thickness.
If you're in a high risk category, anticoagulation drugs such as aspirin, or surgical procedures such as carotid endarterectomy, shunting and stenting may help to prevent a major stroke.
Strokes may also occur in individuals who suffer from heart disease. Some forms of heart disease, such as heart valve problems, may cause blood clotting which could result in stroke. In this case, a doctor may choose to perform surgery, which may correct the dysfunction and possibly prevent a future stroke. Sometimes, preventing stroke in people with a history or risk of heart disease is as simple as monitoring and regulating their blood pressure.
You can also decrease your chance of suffering a stroke by recognising the various risk factors which apply to you and removing them from your lifestyle, when possible.
In the End...
There are people of all shapes, sizes and ages who have been personally affected by stroke. The chances a person has of suffering a stroke in their lifetime is typically dependent on that person's lifestyle, medical history and willingness to maintain overall, general good health. Many of the risk factors associated with stroke are easily avoidable and can be alleviated with good diet, regular exercise and scheduled check ups with a doctor. For those risk factors that can't be alleviated, such as diabetes, pregnancy or age, check with your physician on ways to maintain and monitor your health with regard to stroke.
By working to enhance your overall health, you are also taking the steps needed to avoid suffering from this potentially debilitating, and fatal, illness.
1 This is according to studies on strokes conducted by the American Heart Association and the American Stroke Association.
2 These statistics are provided by The Stroke Association, UK.
3 Statistics provided by the National Institutes of Health, the American Heart Association and the American Stroke Association.
4 The FDA is the US Food and Drug Administration, responsible for regulating medicines in the United States.