Cerebrovascular accident (CVA), also known as stroke, occurs when there is a decrease or blockage of blood supply to the brain. When a stroke occurs, the individual suffering from a stroke should receive urgent medical attention.
Stroke is the fifth leading cause of death in the United States. Almost 800,000 people suffer a stroke in that country. According to a prospective study conducted in Ecuador during 14 years (1991-2015), cerebrovascular disease represented the first cause of mortality (77,897 deaths), with a constant trend over the last 25 years. There are three main types of stroke:
Ischemic stroke: this is the most frequent type of stroke, accounting for 87% of all cases. In this event, a blood clot prevents blood and oxygen from reaching a certain area of the brain.
Hemorrhagic stroke: Occurs when a blood vessel ruptures. It is usually the result of aneurysms or arteriovenous malformations.
Risk Factors for Hemorrhagic Stroke
Risk factors for hemorrhagic stroke include:
1. High blood pressure
2.Coagulation disorders/use of anticoagulant medications
3. Advanced age
4. Recent heavy alcohol consumption
5. Family and personal history of cerebral hemorrhage.
6. Bacterial endocarditis.
7. Connective tissue diseases.
8. Cocaine use.
9. Polycystic kidney disease.
Transient ischemic attack (TIA): This occurs when blood flow to a region of the brain is insufficient and occurs for a brief period of time. Normal blood flow resumes within a short time.
Stroke can be a fatal event. According to the American Heart Association (AHA), the age-specific death rate in 2017 was 37.6 per 100,00 stroke diagnoses.
Causes and risk factors for stroke
Each type of stroke has a different set of causes. However, stroke is more likely to occur in a person if he or she has the following conditions:
1. Overweight and obese.
2. Being older than 55 years of age.
3. Having a personal or family history of stroke.
4. High blood pressure.
5. Diabetes mellitus.
6. High cholesterol and triglycerides.
7. Heart disease (carotid artery disorders, or vascular disease).
8. Sedentary lifestyle, i.e., lack of physical activity.
9. Excessive alcohol consumption.
10. Tobacco use.
11. Use of illicit drugs.
According to some studies, it has been proven that men have a higher risk of death from stroke than women. A 2016 review of studies, however, suggests that these differences do not account for adjustments for race, age, stroke severity, and other risk factors. African Americans have a significantly higher risk of first-time stroke. They are also about 60% more likely to experience a new stroke within 2 years.
In general, the symptoms of a stroke appear without warning. Some of the most important symptoms include:
-Confusion, which includes difficulty speaking and understanding speech.
-Headache, which may occur with altered consciousness.
-Numbness or inability to move areas of the face, arms or legs, especially on one side of the body.
-Vision disturbances in one or both eyes.
-Difficulty walking, including inability to coordinate movements.
-Dizziness and vertigo.
Stroke can lead to long-term health problems. Some people may also experience:
1. Problems with bowel (bladder or bowel) control.
3. Paralysis or weakness on one or both sides of the body.
4. Difficulty controlling or expressing emotions.
It is important to emphasize that symptoms can vary in severity. The acronym FAST is a good way to remember the symptoms of a stroke:
1. Facial: refers to deviation of the corner of the mouth or facial asymmetry.
2. Arm: refers to weakness of a body part.
3. Speech: refers to language disorders, whether presenting with difficulty in expression, difficulty in comprehension, or manifesting with difficulty in articulation of words.
4. Time: refers to the importance of time during a stroke, and therefore the need to seek urgent medical attention.
Stroke sets in quickly. To avoid a fatal event, or serious sequelae, a person who suffers a stroke should receive hospital treatment within 4 hours of the onset of symptoms. There are several diagnostic tests that the physician can employ to determine the type of stroke present. These include:
Physical examination: the physician should question the patient or family members about the symptoms and medical history of the affected person. Muscle strength, reflexes, sensation, vision and coordination of movements should be determined. Blood pressure should also be checked, the neck should be examined to explore and listen to the carotid arteries, and the blood vessels in the back of the eyes (fundus) should be explored.
Blood tests: The medical professional will order blood tests to determine if there is a high risk of bleeding or blood clots, measure the levels of sugar, cholesterol and triglycerides, kidney function tests, coagulation factors, and check for the existence of an underlying infectious process.
Some of the imaging studies used for stroke diagnosis include:
This study can reveal the presence of brain hemorrhages and infarcts, tumors and other conditions within the brain.
Magnetic Resonance Imaging (MRI)
This study can also show lesions in the brain and is more sensitive in the detection of cerebral infarcts, lesions of the brainstem and posterior fossa. It can show alterations in 82% of the cases, while computed tomography does so in 50% of the cases.
Carotid artery ultrasound
This test allows to verify the blood flow in the carotid arteries and to see if there is a narrowing or presence of an atheroma plaque.
In this study, the patient is injected with a contrast material into the cerebral blood vessels in order to visualize them by X-ray or MRI. This provides a detailed view of the cerebral and neck circulation.
The echocardiogram is a detailed ultrasound study of the heart, which allows to verify the presence of clots that could have broken off and gone to the brain.
Stroke treatment should be managed by a team of specialists including neurologists, neurosurgeons, intensivists, physiatrists, among others. Since ischemic and hemorrhagic strokes have different causes and effects on the body, both require different treatments.
Treatment begins with medications to dissolve clots and to prevent clots from forming. Anticoagulants such as aspirin are administered or by injection of tissue plasminogen activator (TPA), a procedure known as thrombolysis. TPA is very effective in dissolving clots. However, the injection must be performed within 4.5 hours after the onset of stroke symptoms. Another treatment option is angioplasty , whereby a small balloon is blown into a narrowed artery using a catheter to resume blood flow. A tube called a stent is then inserted to prevent the artery from narrowing again.
Treatment begins with taking medications that reduce and control blood pressure in general, in case the stroke is caused by a hypertensive crisis. In addition, anticoagulant or antiplatelet drugs such as warfarin or clopidogrel are indicated.
Stroke is a life-changing event that can have lasting physical and emotional effects. Recovery from a stroke will often require specific therapies and support systems including:
-Support from friends and family.
Rehabilitation represents an important and ongoing part of stroke. With proper care and support from family members, it is possible for a person who has suffered a cerebrovascular event to regain a normal or near-normal quality of life, depending on the severity of the stroke.
The most important preventive measures to prevent the occurrence of a cerebrovascular event include:
1. Following a healthy dietary regimen. A healthy and nutritious diet should include fruits, vegetables, whole grains, legumes, seeds, among others. In addition, the consumption of red meat and processed foods, as well as cholesterol and saturated fats, should be limited.
2. Maintain a healthy weight.
3. Regular physical activity.
4. Control and treat constipation.
5. Not smoking tobacco.
6. Avoid alcohol consumption.
7. Blood pressure control.
8. Adequate treatment and control of diabetes.