Stroke - Information Overview

Stroke is an acute cerebrovascular accident characterized by the sudden (within minutes, less often hours) appearance of focal neurological symptoms (motor, speech, sensory, coordination, visual and other disorders) and/or general cerebral disorders (impaired consciousness, headache, vomiting, etc.), which persist for more than 24 hours or lead to the death of the patient in a shorter period of time as a result of a cause of cerebrovascular origin.

Strokes (acute cerebrovascular accident) are a heterogeneous group of diseases caused by a sudden focal cessation of cerebral blood flow, which causes neurological disorders. Strokes can be ischemic (80%), usually caused by thrombosis or embolism; or hemorrhagic (20%) due to a ruptured vessel (subarachnoid or parenchymatous hemorrhage). If focal neurological symptoms resolve within 1 hour, the cerebrovascular accident is classified as a transient ischemic attack (TIA). A stroke involves damage to brain tissue, while TIA, if damage occurs, is much less extensive. In Western countries, stroke is the third leading cause of death and the first leading cause of disability among neurological diseases.

When a cerebral artery supplying blood to an area of the brain is suddenly blocked, the function of the affected area of the brain is immediately lost. If the occlusion persists for a certain period of time, brain tissue undergoes necrosis, leading to a cerebral infarction, which can lead to irreversible loss of function. The goal of stroke treatment, therefore, is to restore blood flow (reperfusion) to the affected area, limit the extent of damage by increasing the brain's resistance to ischemia, and prevent further arterial occlusion. Although achieving these goals is difficult, recent progress has been made in developing effective treatments. This chapter discusses drugs that prevent ischemic stroke and limit the damage to brain tissue associated with it.

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Epidemiology

Stroke epidemiology studies the prevalence and impact of this medical condition on a population. Here are some key points related to stroke epidemiology:

1. Stroke incidence: Strokes are a significant health problem worldwide. They are a leading cause of death and disability in many countries. The incidence of strokes may vary by country and region.
2. Risk Factors: Risk factors for stroke include high blood pressure, smoking, diabetes, high cholesterol, physical inactivity, obesity, uncontrolled alcohol consumption, genetic predisposition, and others.
3. Types of stroke: Ischemic strokes (when blood doesn't reach a certain part of the brain because of a clot or thrombosis) account for most strokes. Hemorrhagic strokes (when there's bleeding in the brain) are less common but more deadly.
4. Age and gender: The likelihood of having a stroke increases with age. However, strokes can affect people of all ages. In some cases, younger people may also have risk factors and a genetic predisposition. Research also points to some differences in stroke incidence between men and women.
5. Effectiveness of preventive measures: Preventive measures such as blood pressure control, risk factor management and lifestyle can significantly reduce the risk of stroke.
6. Public Health Impact: Strokes have a significant impact on public health and the medical system. They can cause long-term disabling consequences and require expensive treatment and rehabilitation.
7. Prevention and education: Prevention and lifestyle education programs aimed at increasing awareness of risk factors and how to manage them play an important role in reducing the incidence of stroke.

Causes stroke

The causes of stroke can be varied and include the following main factors:

1. Ischemic stroke (related to blockage of an artery):

   • Atherosclerosis: The formation of atherosclerotic plaques (cholesterol deposits) on the walls of arteries can lead to narrowing of the vessels and the formation of blood clots.
   • Embolism: Blood clots (embolisms) that break off from other parts of the body, such as the heart, can block an artery in the brain.
   • Carotid artery stenosis: Narrowing of the carotid arteries, usually due to atherosclerosis, can lead to ischemic stroke.

2. Hemorrhagic stroke (related to bleeding):

   • Aneurysms: Aneurysms (bumps) in the blood vessels of the brain can burst, causing bleeding in the brain.
   • Arteriovenous malformations: Birth defects in the vessels known as arteriovenous malformations can be a source of bleeding.
   • High blood pressure: High blood pressure can weaken the walls of your arteries and cause them to rupture.

3. Transient ischemic attack (TIA): A TIA is a temporary interruption of blood flow to the brain that can be caused by the same factors as a stroke, but the symptoms disappear within a short time. A TIA may serve as a warning sign of a stroke.

4. Other risk factors:

   • Diabetes mellitus
   • Smoking
   • Physical inactivity
   • Obesity
   • High cholesterol
   • Uncontrolled alcohol consumption
   • Genetic predisposition
   • Atrial fibrillation (heart arrhythmia)
   • Uncontrolled blood pressure

Pathogenesis

Stroke pathogenesis is a medical term that describes the mechanisms and processes that lead to the development of a stroke. The pathogenesis of a stroke may vary depending on its type (ischemic or hemorrhagic), but common points include the following aspects:

1. Ischemic stroke:

   • Blocked artery: Ischemic stroke most often occurs due to a blockage (clogged) artery that supplies blood to the brain. This can be caused by atherosclerotic plaque (cholesterol deposits) building up on the artery walls or by a thrombus (clot) forming in the artery.
   • Lack of oxygen: When an artery is blocked, blood and oxygen cannot reach a certain part of the brain, resulting in a lack of oxygen and nutrients to that area.
   • Neuronal death: Lack of oxygen and nutrients causes neurons (nerve cells) in the brain to die. This process can begin soon after the artery becomes blocked.

2. Hemorrhagic stroke:

   • Hemorrhagic stroke: A hemorrhagic stroke occurs when a blood vessel in the brain ruptures, causing blood to leak into surrounding tissue. This can be caused by an aneurysm (bump) in the vessel, an arteriovenous malformation (a birth defect in the blood vessels), high blood pressure, or other factors.
   • Brain Damage: Blood leaking from a ruptured vessel can damage brain tissue, causing swelling and damage to neurons.

The common result of both ischemic and hemorrhagic stroke is damage to brain tissue and disruption of neural function in the affected area. This can lead to various neurological symptoms, such as loss of sensation, paralysis, speech impairment, etc.

Understanding the pathogenesis of stroke is important for developing prevention and treatment strategies.

Symptoms stroke

Stroke symptoms can vary depending on the type of stroke (ischemic or hemorrhagic), the area of the brain that is affected, and the severity. Below are common symptoms that a patient may experience when having a stroke:

1. Loss of strength on one side of the body: One of the most common signs of a stroke is one-sided paralysis or weakness in an arm, leg, or half of the face. This may manifest as difficulty raising an arm, limping, an asymmetrical smile, or a drooping corner of the mouth.
2. Speech disorders: Patients may have difficulty pronouncing words, formulating sentences, or understanding other people's speech. This condition is called aphasia.
3. Loss of sensation: Some strokes can cause loss of sensation on one side of the body or in certain areas.
4. Vision loss: A stroke can cause temporary or permanent vision loss in one or both eyes, as well as double vision.
5. Headache: Stroke can be accompanied by a severe and unbearable headache, often described as "the worst headache of my life."
6. Dizziness and loss of balance: Patients may experience dizziness, unsteadiness when walking, and loss of balance.
7. Coordination problems: Patients may have difficulty coordinating movements and performing simple tasks.
8. Difficulty swallowing: Stroke can cause dysphagia, which means difficulty swallowing food and liquids.
9. Seizures: Some patients may experience seizures or painful muscle contractions after a stroke.
10. Disturbances of consciousness: Stroke can cause changes in consciousness, including loss of consciousness or coma.

Forms

Stroke can manifest itself in different forms, the main ones being ischemic stroke and hemorrhagic stroke. Here is a more detailed description of each form:

• Ischemic stroke: This type of stroke is the most common, accounting for about 85% of all strokes. It occurs when an artery supplying blood to the brain becomes clogged by a blood clot (thrombosis) or an embolus (embolism), blocking blood flow to a specific area of the brain. This results in a lack of oxygen and nutrients to that area, causing neuronal death. Symptoms of ischemic stroke can vary depending on which part of the brain is damaged.
• Hemorrhagic stroke: A hemorrhagic stroke occurs when a blood vessel in the brain ruptures and causes bleeding into the brain tissue. This can be caused by an aneurysm (a bulge) in the vessel, an arteriovenous malformation (a birth defect in the blood vessels), or high blood pressure. Hemorrhagic strokes can be extremely dangerous because the blood can damage surrounding tissue and cause pressure within the skull.
• TIA (transient ischemic attack): A TIA is a temporary interruption of blood flow to the brain that causes temporary neurological symptoms similar to those of an ischemic stroke. However, TIA symptoms usually resolve within minutes to hours and do not leave lasting neurological consequences. A TIA is often a warning sign of a possible future stroke.
• Cryptogenic stroke: This term is used when the cause of the stroke cannot be determined with certainty. Cryptogenic strokes can include both ischemic and hemorrhagic forms.

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Complications and consequences

Stroke is a serious medical condition that can cause various complications, both immediately after the stroke and in later stages. Some of the common complications of stroke are listed below:

1. Paralysis and mobility impairment: A stroke can cause partial or complete paralysis in various parts of the body, limiting the patient's ability to care for themselves and their mobility.
2. Speech and communication impairments: Many stroke patients experience speech and communication impairments. This may include aphasia (impaired speech and understanding), dysphagia (difficulty swallowing), and other problems.
3. Sensory loss: A stroke can cause loss of sensation in certain parts of the body, which can increase the risk of injury and make it difficult to perform normal activities.
4. Emotional and psychological problems: Stroke patients may experience depression, anxiety, mood changes, and other psychological problems.
5. Pneumonia: Patients with difficulty swallowing (dysphagia) may be at risk of aspiration (inhalation of food or liquid), which can cause pneumonia.
6. Urinary disorders: Incontinence (inability to hold urine) can be a problem after a stroke.
7. Lifestyle and social changes: A stroke can change a patient's lifestyle, limiting their ability to work, care for themselves, or participate in social activities.
8. Recurrence: Patients who have had a stroke have an increased risk of developing new strokes, so risk factor control and prevention are important.
9. Other complications: This includes complications related to medication use, long-term hospital treatment and rehabilitation, as well as physical limitations and lifestyle changes.

Diagnostics stroke

Stroke diagnostics include a number of clinical, laboratory and instrumental methods that allow you to determine the type of stroke, its causes and severity. It is important to begin diagnostics as soon as possible, as prompt treatment can significantly improve the prognosis. Here are the main steps in diagnosing a stroke:

1. Clinical examination:

   • The doctor conducts a clinical examination of the patient, assessing his symptoms and medical history.
   • It is important to determine when stroke symptoms began, as a rapid onset may indicate a stroke.
   • The doctor also evaluates brain functions, including consciousness, motor skills, sensation, speech, and motor coordination.

The purpose of the clinical examination is to confirm the diagnosis of stroke, determine its nature (ischemic or hemorrhagic) and assess the need and scope of emergency measures. Stroke should be suspected in the case of sudden development of neurological deficit corresponding to the lesion of a certain area of the arterial blood supply to the brain; especially in the case of sudden onset of severe headache, impaired consciousness or coma.

2. Available data:

   • Your doctor may look for risk factors for stroke, such as high blood pressure, diabetes, high cholesterol, smoking, and others.

3. Instrumental studies:

   • Computed tomography (CT) scan of the brain: This is often the first step in diagnosing a stroke and can show bleeding and other changes in the brain.

Urgent CT of the brain is indicated to differentiate hemorrhagic and ischemic stroke and to detect signs of intracranial hypertension. CT has a high enough sensitivity to detect foci of hemorrhage, but in the first hours after ischemic stroke in the anterior vascular bed, pathological changes on CT are unlikely. CT is also unlikely to detect small focal ischemic stroke in the posterior vascular bed and up to 3% of subarachnoid hemorrhages. In cases where impaired consciousness is not accompanied by obvious signs of lateralization, additional types of research are indicated to establish causes of the disease not related to stroke. If the clinical diagnosis of stroke is not confirmed by CT results, MRI is indicated to verify the ischemic nature of the disease.

• Magnetic resonance imaging (MRI) of the brain: MRI can provide more detailed images of brain tissue and blood vessels and is often used for additional evaluation.
• Angiography: This is a blood vessel test that can help detect narrowing or blockage of arteries in the brain.
• Electroencephalography (EEG): An EEG can be used to assess the brain's electrical activity and detect epileptic seizures, which can sometimes accompany a stroke.
• Echocardiography: A heart scan may be done to look for the source of emboli (blood clots) that can cause a stroke.

4. Laboratory tests:

   • A blood test can help determine your sugar and cholesterol levels, as well as other tests to identify risk factors.

Differential diagnosis

Differential diagnosis of stroke involves identifying symptoms and signs that may indicate other medical conditions that mimic stroke symptoms. This is important to rule out other possible causes of the symptoms and to make the correct diagnosis. Some of the conditions that can mimic stroke symptoms include:

1. Hypoglycemia (low blood sugar): Low blood glucose can cause stroke-like symptoms, such as weakness, tingling, changes in consciousness, and even loss of consciousness.
2. Epileptic seizures: Epileptic seizures can involve loss of consciousness, unexplained confusion, involuntary movements, and even loss of consciousness.
3. Migraine: Migraine can cause severe headaches as well as stroke-like symptoms such as weakness and numbness.
4. Transient ischemic attack (TIA): Also known as a "mini-stroke," a TIA can have similar symptoms that go away within a short time.
5. Neurological diseases: Some neurological diseases such as fungal infection of the brain, degenerative diseases, etc. may present symptoms that may initially be mistaken for a stroke.
6. Acute migraine with auras: Acute migraine with auras can cause temporary visual impairment and other symptoms that may be similar to those of a stroke.
7. Deciphering syndrome (delirium): A state of clouded consciousness that can be caused by a variety of reasons, including infections, electrolyte imbalances, poisoning, and others.

Treatment stroke

Treatment for stroke depends on its type (ischemic or hemorrhagic), severity, time since symptoms began, and other factors. Stroke requires immediate medical attention and specialized treatment because a quick response can save lives and minimize brain damage. Here are the general principles of stroke treatment:

1. Ischemic stroke:

   • Thrombolysis: If the patient is suitable for this procedure and the onset of symptoms is within 4.5 hours, intravenous thrombolysis may be performed, which helps dissolve the clot and restore blood flow to the brain.
   • Endovascular treatment: In cases where thrombolysis is not available or is ineffective, endovascular clot removal (thrombectomy) may be performed using specialized equipment.

2. Hemorrhagic stroke:

   • Surgery: Hemorrhagic stroke may require surgery to remove blood from the brain tissue, stop the source of bleeding, or take other steps to eliminate the cause of the bleeding.

3. Supportive therapy:

   • Stroke patients may require life-sustaining measures such as ventilation and intensive care.
   • Monitoring and control of blood pressure, blood sugar levels and other important parameters.

4. Rehabilitation:

   • Rehabilitation therapy, including physical, speech, and occupational therapy, helps restore function and improve quality of life after a stroke.
   • Long-term rehabilitation may include exercise, motor skills training, learning self-care skills, and adaptation to a new living situation.

5. Preventing recurrence: After a stroke, it is important to take treatment and measures to manage risk factors to prevent another stroke from occurring.

Treatment requires teamwork of specialists including neurologists, surgeons, rehabilitation specialists and nurses. It is important that treatment begins as soon as possible and that the patient receives appropriate medical care and rehabilitation to restore function and improve quality of life after a stroke.

Prevention

Stroke prevention plays a critical role in preventing this serious medical condition. The following steps and measures can help reduce your risk of stroke:

1. Blood Pressure Management:

   • Measure your blood pressure regularly and monitor its readings.
   • If necessary, use medications to control high blood pressure under the supervision of a doctor.

2. Cholesterol level:

   • Reduce your blood cholesterol levels through healthy eating and, if necessary, medication as recommended by your doctor.

3. Diabetes management:

   • If you have diabetes, monitor your blood sugar regularly and follow your doctor's recommendations for treatment and diet.

4. Smoking Cessation:

   • Stopping smoking is one of the most important steps in preventing stroke, as smoking increases the risk of cardiovascular disease.

5. Healthy eating:

   • Eat a balanced diet, increasing your intake of vegetables, fruits, and lean proteins and decreasing your intake of saturated fat, salt, and sugar.

6. Physical activity:

   • Incorporate regular exercise into your lifestyle. It helps maintain cardiovascular health.

7. Weight Management:

   • Maintain or strive for a healthy weight, as being overweight can increase your risk of stroke.

8. Stress Management:

   • Practice stress management techniques such as meditation, yoga, deep breathing and relaxation.

9. Limit alcohol consumption:

   • Drinking alcohol in moderation may be acceptable, but avoid drinking to excess as it may increase your risk of stroke.

10. Medical control:

    • Get regular medical checkups and follow your doctor's recommendations for managing risk factors.

11. Preventive medications:

    • In some cases, your doctor may prescribe medications to reduce your risk of stroke, especially if you have a high risk.

Remember, prevention is key to maintaining cardiovascular health and preventing this serious medical event. Maintaining a healthy lifestyle, regular medical checkups, and managing risk factors can significantly reduce your chances of having a stroke.

Forecast

The prognosis for a stroke depends on many factors, including the type of stroke, its severity, the patient's age, the speed and effectiveness of medical care, and the patient's additional medical conditions. Here are some general aspects of the prognosis:

1. Type of stroke: The prognosis can vary greatly depending on the type of stroke. Ischemic strokes (when an artery is blocked) usually have a better prognosis than hemorrhagic strokes (when there is bleeding in the brain).
2. Severity: The severity of a stroke can range from mild sensory loss to extreme consequences, including paralysis and loss of consciousness. Milder cases of stroke usually have a better prognosis.
3. Speed of medical care: Rapid response and medical care can significantly improve the prognosis. Ischemic stroke can be successfully treated with thrombolysis, but this requires immediate action. The sooner treatment begins, the less damage to the brain.
4. Age of the patient: The prognosis may depend on the age of the patient. Older people may have a more complex prognosis, especially if they have other chronic conditions.
5. Additional medical conditions: Having other medical conditions, such as diabetes, high blood pressure, or heart problems, can worsen the prognosis and complicate stroke treatment.
6. Rehabilitation: The quality of rehabilitation and adherence to rehabilitation recommendations also play an important role in prognosis. Effective rehabilitation can help the patient regain lost skills and improve quality of life.

It is important to note that strokes have different effects on different people, and the prognosis may vary from person to person. The main focus should be on stroke prevention and risk factor management activities to reduce the likelihood of stroke. Rapid response and timely treatment can also significantly improve the prognosis in the event of a stroke.

References

Gusev, E. I. Neurology: national leadership: in 2 volumes / ed. E. I. Guseva, A. N. Konovalova, V. I. Skvortsova. - 2nd ed., revised. and additional - Moscow: GEOTAR-Media, 2021