Stroke (CVA)

The terms cerebrovascular attack (CVA), cerebrovascular accident (CVA), acute cerebrovascular accident (CVA), cerebral infarction , stroke or apoplexy are used as synonyms for the medical term stroke .

Summary

[ hide ]

  • 1 Two types of stroke
    • 1 Ischemic stroke
    • 2 Hemorrhagic stroke
    • 3 Risk factors
      • 3.1 Non-modifiable risk factors
      • 3.2 Modifiable risk factors
      • 3.3 Risk factors related to women
    • 2 Symptoms
      • 1 Resulting disabilities
        • 1.1 Paralysis
        • 1.2 Cognitive deficit
        • 1.3 Language deficit
        • 1.4 Emotional deficit
        • 1.5 Pain
      • 3 Diagnosis
      • 4 Forecast
      • 5 See also
      • 6 Source

Two types of stroke

Stroke has two distinct forms:

  • ischemic stroke, ischemic stroke , stroke, or ischemic stroke : an ischemia (significant decrease in blood flow) caused by the blockage of a blood vessel that supplies blood to the brain, abnormally abruptly. They constitute 80% of the cases.
  • stroke, hemorrhagic stroke , hemorrhagic stroke , cerebral hemorrhage or stroke bleeding : bleeding caused by the rupture of a vessel blood in the brain.

Ischemic stroke

Brain cells, when they stop receiving oxygen or nutrients from the blood (ischemia), die. This ischemia eventually leads to heart attack, the death of brain cells, which are displaced by a fluid-filled cavity. Not all cells in the affected territory die immediately, but there is a part that is “at risk of dying”, and with proper treatment they can be saved. The evolution will depend on the intensity and location of the ischemia and the brain’s ability to recover.

There is a picture that starts exactly the same as the stroke, but then it resolves without leaving symptoms or significant deficit, it is the so-called “transient ischemic attack” and it is a warning that the person is at risk of having a serious stroke.

The most common cause is blood clots. When blood clots form in the wrong place within the artery, they cause an injury that interferes with the normal flow of blood. As age advances, clotting problems are more frequent.

Clots cause ischemia and heart attack in two different ways:

  • A clot somewhere in the body travels through the blood vessels and becomes trapped in a cerebral artery; The free clot is called the embolus: embolic stroke.
  • A blood clot forms in one of the cerebral arteries, remaining fixed in the wall, until it increases in size enough to block blood flow to the brain: thrombotic stroke.

Another mechanism by which an ischemic stroke can occur is by narrowing a small or large artery (stenosis) by accumulation of plaque (a mixture of fatty substances, such as cholesterol and other lipids). The most common form is arteriosclerosis, in which plaque deposits accumulate along the inner walls of the medium and large arteries. This accumulation causes an increase in thickness, hardening and loss of elasticity, with a reduction in blood flow.

Hemorrhagic stroke

Neurons, under normal conditions, do not come into contact with the blood, since it is separated by a structure called glia that forms a barrier that surrounds the blood vessels and capillaries to control which elements of the blood can pass.

When an artery in the brain breaks, not only is the blood supply disturbed, but the chemical balance required by neurons to function properly.

Bleeding can occur in several ways:

  • Bleeding aneurysm: There is a weak place in the arterial wall that dilates or swells under high blood pressure, and can rupture and spill blood into the space around the brain cells.
  • Breakage of the arterial wall. If there is a plaque embedded in the arterial wall, it loses its elasticity, becoming brittle and prone to rupture in the case of hypertension.
  • Arteriovenous malformation: a conglomerate of defective blood vessels and capillaries that have thin walls and are prone to rupture.

Risk factor’s

Stroke attack.

There are some people at higher risk of having a stroke:

Non-modifiable risk factors

  • Although it can occur in any age group, older people are at higher risk. For every decade above 55 years, the risk of stroke doubles and 65% occurs in those over 65 years of age.
  • Men have a higher risk of having a stroke, but women have a higher mortality, since they are generally older when they occur.
  • The environment and lifestyle are factors that play an important role in stroke risk.
  • Family history of stroke. Family members may have a genetic tendency to stroke risk factors, such as an inherited predisposition to hypertension or diabetes. The influence of a common lifestyle among family members could also contribute to family stroke.
  • Head and neck injuries: can damage the cerebrovascular system causing a small number of attacks: can cause bleeding, tension in the vertebral and carotid arteries, possibly leading to an ischemic stroke.

Modifiable risk factors

  • Blood pressure. High blood pressure is the most powerful risk factor that exists; the hypertensive is 4 to 5 times more likely to have a stroke than the normotensive. HT is the first cause of cerebrovascular complication, so that 50% of patients who have a stroke are hypertensive, and 20% of severe hypertensive patients develop a stroke. Hypertension as a risk factor decreases in importance as age increases, so other additional factors play a greater role in stroke risk in older people.
  • Heart disease. Fundamentally, atrial fibrillation, in which there is an irregular flow of blood and a greater possibility of formation of clots that can be transferred to the brain. The risk increases considerably with age. Malformations of the heart valves also pose a greater risk. There is a malformation of the heart, called Foramen Ovale (opening that connects the two atria) that represents a greater risk;
  • It is the most powerful modifiable risk factor. Cigarette smoking almost doubles the likelihood of having a stroke, regardless of other risk factors. The relative risk of stroke decreases immediately after smoking cessation, with a significant reduction in risk observed after 2 to 4 years. Cigarette smoking promotes Arteriosclerosis and increases blood clotting factor levels.
  • Cholesterol levels. Cholesterol is a vital substance for our body as it contributes to the production of hormones and vitamin D, in addition to being an integral component of cell membranes. The natural production of cholesterol by the liver is not a risk factor, but that from a diet with high cholesterol levels is. Foods high in saturated fat and cholesterol can increase total cholesterol levels alarmingly, contributing to the risk of Arteriosclerosis and increased thickness of the arteries. Cholesterol is not soluble in water (it is a fat) and therefore not in the blood and to be able to move through it it needs to be covered by a layer of protein: lipoprotein. We have two kinds of cholesterol: good or high-density lipoprotein (HDL) and bad or low-density lipoprotein (LDL). Most of the cholesterol in the body is in the form of low-density lipoprotein, or LDL, or “bad cholesterol,” which circulates through the blood stream, collecting excess cholesterol and depositing cholesterol where it is needed (for example, for production and maintenance of cell membranes). But when too much cholesterol begins to circulate in the blood, the body cannot handle excess low-density lipoprotein and accumulates along the inside of the artery walls. This accumulation becomes plaque leading to stenosis and Arteriosclerosis. LDL levels should be less than 130 mg / mL. Values ​​above 160 put a person at high risk for a heart attack or stroke. The HDL form contributes to the prevention of strokes, since instead of depositing cholesterol inside the arterial walls, it returns to the liver to discharge it and this eliminates the excess through the kidneys. Values ​​greater than 35 mg / mL are desirable. A healthy diet and exercise practice are the best measures to reduce cholesterol levels.
  • Diabetics are three times more at risk of having a stroke, reaching the highest point between fifty and sixty years, decreasing from this age. It is also added that the prevalence of hypertension is 40% higher in the diabetic population. Good control of sugar and blood pressure is essential.
  • Excessive alcohol consumption. Normally, excessive alcohol consumption leads to an increase in blood pressure, but different studies show that moderate consumption has a protective influence against ischemic stroke, probably because alcohol reduces the coagulation capacity of platelets in the blood. Drinking excessive amounts of alcohol can cause a rebound effect once alcohol has been removed from the body: it significantly increases blood viscosity and platelet levels, increasing the risk of ischemic stroke.
  • Consumption of drugs. Cocaine can act on other risk factors such as hypertension, heart disease, and vascular disease; It also reduces cerebrovascular blood flow by up to 30%, leading to narrowing of the arteries. It affects the heart producing arrhythmias and accelerates the heart rate that can lead to the formation of blood clots. Other drugs such as amphetamines, heroin, and anabolic steroids increase the risk of having a stroke, as they can cause blood vessels to narrow and blood pressure to rise.

Risk factors related to women

Pregnancy and childbirth can put a woman at a higher risk of having a stroke, although in young women the risk is small. Approximately 25% of strokes during pregnancy end in death and are the leading cause of maternal death in the United States. The cause is unknown, but the greatest risk occurs in the postpartum stage.

As during pregnancy and childbirth, hormonal changes at the end of the reproductive years can increase the risk of stroke. Hormone replacement therapy can reduce some of the effects of menopause and decrease the risk of stroke. The mechanism by which estrogen can be beneficial for postmenopausal women could be its role in cholesterol control. Various studies have shown that estrogen increases levels of high-density lipoprotein (good cholesterol), and reduces levels of low-density lipoprotein (bad cholesterol).

Non-modifiable risk factors

  • Age
  • Sex
  • Heritage
  • Race
  • Geography
  • Weather

Well established risk factors

  • Arterial hypertension.
  • High-risk heart disease.
  • Mellitus diabetes.

Transient ischemic accident Potential modifiable risk factors

  • Lipid disorders (cholesterol, etc.).
  • Sedentary lifestyle.
  • Others: oral contraceptives, menopause, migraine, etc.

Stroke in children

There are a number of medical complications that can lead to strokes in children:

  • Intracranial infection.
  • Brain injury.
  • Vascular malformations:
  • Occlusive vascular disease
  • Genetic disorders: sickle cell anemia, tuberous sclerosis and Marfan syndrome.

Stroke in children has special characteristics. You may have seizures, sudden loss of speech, expressive language, weakness on one side of the body (hemiparesis), paralysis on one side of the body (hemiplegia), speech impediment (dysarthria), headache, or fever.

Most children recover better than adults, due in large part to the plasticity of the immature brain and the children’s ability to adapt to deficits.

Epidemiology

CVA is the third leading cause of death in Cuba. Although it can appear at any age, 70% of cases occur in those over 65 years of age and are more likely in men.

It constitutes the second cause of disability and chronic disease and as the sequelae are highly variable depending on the location and extent of ischemia, the degree of disability is also highly variable.

symptom

Symptoms appear suddenly and more than one symptom occurs at the same time, making it easily distinguishable from dizziness or headache.

The most characteristic symptoms are:

  • Sudden numbness or weakness, especially of a part of the body.
  • Sudden confusion or problems with speech or understanding.
  • Sudden vision problems in one or both eyes.
  • Sudden trouble walking, dizziness, or loss of balance or coordination.
  • Sudden, severe headache with no known cause.

Before any of these symptoms, do not wait, go to the emergency room.

Resulting disabilities

Some of the disabilities that can result from a stroke are:

Paralysis

It is very common for paralysis to occur on one side of the body, called hemiplegia. Weakness of one side of the body, called hemiparesis, can also occur. Paralysis or weakness can affect only the face, one limb, or it can affect an entire side of the body. The side that is affected is the opposite to the cerebral hemisphere that has suffered the accident. Motor deficits can result from damage to the motor cortex in the frontal lobes of the brain or in the lower parts of the brain, such as the cerebellum, which controls balance and coordination.

Cognitive deficit

Problems of reasoning, conscience, attention, judgment and memory can occur. You may not be aware of one side of your body or one side of your visual field and are not aware of your deficit. You may be unaware of your surroundings or you may not be aware of mental deficits resulting from stroke.

Language deficit

Problems understanding (aphasia) or making sentences (dysarthria). They are usually a consequence of damage to the temporal and parietal lobes of the brain.

Emotional deficit

There may be problems controlling your emotions or expressing inappropriate emotions in certain situations. A very common problem is depression, which can make recovery and rehabilitation difficult and even lead to suicide.

Pain

A type of central pain can occur, due to damage to an area of ​​the brain called the thalamus. It is a mixture of sensations, such as heat and cold, burning, tingling, lack of sensitivity, sharp stitches and intense pain. There are few treatments to combat this pain.

Diagnosis

Doctors have different tools to diagnose the cause of a stroke accurately and quickly. The steps are the following:

  • Neurological examination
  • Blood test.
  • Computed tomography. A series of cross-sectional images of the head and brain are created and is the preferred technique for diagnosis. It quickly rules out bleeding, may show a tumor, and may even present evidence of an early heart attack. If the stroke is caused by bleeding, it can show evidence almost immediately after symptoms appear.
  • Magnetic resonance: uses magnetic fields to detect changes in brain tissue. With this technique, small infarcts can be better detected immediately after the onset of stroke. The downside is the shortage of appliances (not available in all hospitals) and their cost. It is also not reliable to determine if the patient is bleeding; Because it takes more time to perform the test than tomography, it should not be used if you delay treatment.
  • Others:
  • Magnetic resonance angiography.
  • Functional magnetic resonance.
  • Doppler ultrasound. Sound waves are sent to the neck, the echoes bounce off the moving blood and tissue in the artery and can become an image. It is a fast, painless, risk-free and relatively inexpensive method, but it is not as accurate as arteriography.
  • This is an x-ray of the carotid artery taken when a special dye is injected into the artery. This procedure carries its own small risk of causing a stroke and is expensive to perform. It is the best way to measure carotid artery stenosis.

Different scales are used to assess neurological damage, asking you to answer different questions and perform different physical and mental tests.

Forecast

Until recently, medicine has been able to do very little for affected people, but evolution has been very rapid and new and improved therapies are developed every day, so that, if there has been early treatment, people who have suffered an acute cerebrovascular accident (CVA) they can leave it without disability or with very little.

Approximately 25% of people who recover from a stroke have another one within 5 years: recurrent stroke, which is an important element that contributes to incapacitation and death. The risk is greater immediately after having an episode and decreases over time; 3% of stroke patients will have another stroke within 30 days of the first stroke, and a third will occur within the first 2 years of the first stroke.

  • Poor prognosis factors
  • Poor prognosis factors
  • Bladder or bowel incontinence
  • Significant involvement of half the body
  • Perception deficit
  • Serious cognitive disturbances
  • Previous ACVA (acute cerebrovascular attack)
  • Associated complex medical problems
  • Global aphasia

Treatment

The therapy the patient receives will depend on the stage of the disease.

There are normally three stages in the treatment:

  • Stroke prevention
  • Immediate therapy.
  • Rehabilitation

In this section we will deal with immediate treatment.

Drug treatment

The most commonly used drugs are:

  • Antithrombotic agents (antiplatelet and anticoagulant agents).
  • Thrombolytic agents.
  • Neuroprotectors

Antithrombotic agents

They prevent the formation of blood clots by reducing the activity of platelets, which are the blood cells that contribute to the coagulant property of blood. Antithrombotic agents are normally used for prevention purposes. The most used agents are:

Anticoagulants reduce the blood’s clotting property and the most widely used are warfarin and heparin.

Thrombolytic agents

They are used to treat acute stroke while it is occurring. They dissolve the clot that is blocking blood flow to the brain. They should only be used after careful evaluation of the patient.

Neuroprotectors

They protect the brain against a secondary injury caused by a stroke. There are different types: calcium antagonists, like nimodipine, antioxidants, apoptosis inhibitors, etc.

Surgery

It can be used as prevention, treatment of an acute accident or to repair vascular damage. The two fundamental types are:

  • Carotid endarterectomy: Fatty deposits are removed from inside a carotid artery, which are the main providers of blood to the brain.
  • Extracranial / intracranial shunt. Blood flow to a blood-deprived area of ​​the brain is restored by shunting a healthy artery in the scalp to the affected area of ​​brain tissue. It is not a widely used technique due to its dubious usefulness.
  • Detachable loop technique.

Preventive measures

The measures to prevent a first accident or avoid recurring accidents are based on the treatment of risk factors:

  • Arterial hypertension.
  • Atrial fibrillation.
  • Prevent the general formation of clots, regardless of whether there are risk factors

 

Leave a Comment