Ischemic stroke: What is it? Symptoms, Risk Factors, Causes, Types, Diagnosis, Treatment and Prevention

It is the lack of blood in a region of the brain due to a blockage in a cerebral blood vessel.

Also known as  ischemic stroke, it can cause serious sequelae or even death of the person, if it is not treated in time.

Transient ischemic stroke is a less serious type of ischemic stroke and occurs when the blood supply to the brain is interrupted for a short period of time.

The symptoms of transient ischemic stroke are felt for a short time, between 1 and 2 hours, disappearing within 24 hours.

Ischemic and hemorrhagic stroke

The difference between ischemic stroke and hemorrhagic stroke are:

  • Ischemic stroke: occurs due to lack of blood in the brain.
  • Hemorrhagic stroke: occurs due to extravasation of blood in the brain.

The symptoms are similar in both types of stroke, because of the bleeding, patients can feel the pressure inside the head.

The treatment of ischemic and hemorrhagic stroke is different. In the first case, the goal is to resolve the blockage of the artery that causes the stroke, while in the second the treatment is done to prevent brain hemorrhage.

Causes of ischemic stroke

An ischemic stroke occurs as a result of atherosclerosis , which is a condition in which fatty deposits or plaque build up in the body’s blood vessels.

When enough plaque builds up at one point, it can prevent blood from reaching vital organs.

Sometimes a blood clot can move through the blood vessels and stick to a buildup of plaque, which also creates a blockage.

The neck contains arteries known as the carotid arteries that supply blood to the brain. If one of the carotid arteries becomes blocked with plaque, this can result in a stroke.

When the carotid arteries contain plaque buildup, this is known as carotid artery disease and is a major risk factor for stroke.

Atherosclerosis can occur in other arteries, such as those leading to the heart. These are known as coronary arteries. If a blockage occurs in a coronary artery, a heart attack can occur.

Atherosclerosis doesn’t have any symptoms, so many people don’t know they have it until they have a stroke or heart attack.

Risk factors for ischemic stroke

The main risk factors for ischemic stroke and carotid artery disease are the same. They include:

  • High blood pressure: High blood pressure is the main cause of a stroke.
  • Diabetes: People with diabetes are four times more likely to have carotid artery disease.
  • Atherosclerosis or carotid artery disease, or a family history of these conditions.
  • Atrial fibrillation (Afib): 15 percent of embolic strokes occur in people who have Afib.
  • Cholesterol levels: This can include high “bad” LDL cholesterol or low “good” HDL cholesterol.
  • Inactivity – Not exercising can lead to high blood pressure, high cholesterol, and being overweight, making a person more likely to have plaque buildup in the arteries.
  • Being overweight or obese.
  • An unhealthy diet: Eating too many foods with saturated or trans fats, cholesterol, sodium, and sugar can lead to diabetes, plaque buildup, high blood pressure, and high cholesterol.
  • Being over 55 years old: The risk of stroke increases after the age of 55 and increases with each additional decade of life.

Another risk factor is having had a previous transient ischemic attack (TIA). A TIA, or ‘mini stroke’, is a temporary blockage of blood to the brain.

The symptoms of a TIA are the same as an ischemic stroke, but generally last less than 5 minutes and do not cause permanent damage.

About a third of people who have a TIA will have a more serious stroke within 1 year.

Smoking can increase plaque build-up in blood vessels, increase the chance of blood clotting, cause unhealthy cholesterol levels, narrow blood vessels, and damage the lining of blood vessels.

All of these factors also put someone at higher risk of having a stroke.

Types of ischemic stroke

All ischemic strokes are caused by a disruption of the blood supply to the brain. But, ischemic strokes can start in different areas of the body and can be caused by several types of obstructions:

  • An embolic stroke occurs when an embolus, which is a blood clot, piece of plaque, or other object, forms elsewhere in the body and travels to the blood vessels in the brain.
  • A thrombotic stroke occurs when a thrombus or clot forms within one of the blood vessels within the brain.

Symptoms

Strokes can be very dangerous, so it is important to seek medical attention immediately if warning signs appear.

Ischemic stroke symptoms often affect only one side of the body and develop quickly.

The American Stroke Association recommends that people remember FAST. This means:

  • F: drooping face, especially one side of the face drooping or feeling numb. People can verify this by asking the person to smile or stick their tongue out; If your smile is uneven or your tongue drifts to one side instead of the middle, this could be a warning sign.
  • A: Arm weakness, not being able to lift an arm, or feeling weak or numb in one arm.
  • S: speech problems, such as not being able to speak or repeat a sentence clearly.
  • T: time to call 9-1-1.

Beyond FAST, a stroke can also cause the following symptoms that appear very quickly and appear suddenly:

  • Not being able to move one side of the body.
  • Trouble walking or dizziness, falling without cause.
  • Confusion, inability to understand speech.
  • Vision problems or trouble seeing.
  • A severe headache with no apparent cause.

Diagnosis

Strokes start quickly and often occur before a doctor can see an individual for a proper diagnosis.

In order for a person experiencing a stroke to obtain the best possible diagnosis and treatment, they must receive treatment in a hospital within 3 hours of the onset of symptoms.

There are several different types of diagnostic tests that doctors can use to determine what type of stroke has occurred:

  • Physical exam: A doctor will ask about your symptoms and medical history. They can monitor blood pressure, listen to the carotid arteries in the neck, and examine the blood vessels in the back of the eyes for signs of clotting.
  • Blood tests: A doctor can perform blood tests to determine how quickly clots are occurring, the levels of particular substances in the blood, including clotting factors, and whether or not an infection exists.
  • CT scan: A series of X-rays can show bleeding, 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 to check blood flow in the carotid arteries and to see if any plaque is present.
  • Cerebral angiogram: Dyes are injected into the blood vessels of the brain to make them visible on the x-ray. This provides a detailed view of the brain and blood vessels in the neck.
  • Echocardiogram: This creates a detailed picture of the heart to check for sources of clots that could have traveled to the brain to cause a stroke.

The type of stroke someone has had can only be confirmed by performing a brain scan in a hospital setting.

Ischemic stroke treatment

With one hit, every minute counts. The brain depends on a constant supply of oxygen-rich blood, so a blockage that lasts for only a few minutes can begin to damage and kill brain cells.

If a person has signs of a stroke, someone should call 9-1-1. Treatments for ischemic stroke include:

Medications: A clot-busting drug called tissue plasminogen activator (tPA) is given through a vein in the arm.

It must be given within 4 hours of the onset of stroke symptoms for it to work. The earlier tPA is administered, the better the result.

Surgery to remove the clot: After the patient receives APT, they may undergo a procedure known as a mechanical thrombectomy, which involves removing the clot with a catheter.

This procedure should be done within 6 hours of symptoms.

Prevention of an ischemic stroke.

With a stroke, prevention is better than treatment. Even people with risk factors or a history of stroke can take steps to be healthier.

The following measures can help prevent a stroke and improve overall health:

  • Regular medical tests: high blood pressure and cholesterol have no visible symptoms; therefore, getting tested regularly is the only way to know if a person has them.
  • Exercising regularly – Being active reduces your risk of diabetes, high blood pressure, high cholesterol, and other conditions related to ischemic stroke.
  • Eat a heart-healthy diet: A diet should be low in “bad” fats like saturated and trans fats and sodium. Eating more fruits, vegetables, whole grains, healthy fats, and lean protein helps keep your blood vessels healthy.
  • Lose weight if necessary: A healthy weight reduces stroke risk factors.
  • Avoid Smoking or Being Around Smoke – Smoking and breathing other people’s smoke damages blood vessels and increases the risk of stroke-related health problems.
  • Be aware of family history – Always discuss a family history of stroke or TIA with a doctor.
  • Discuss daily prevention with aspirin: People should consult their doctors about taking a low dose of aspirin to prevent a stroke. This treatment is not suitable for everyone.
  • Get enough sleep and manage stress: Getting 7 to 8 hours of sleep and trying to reduce stress can help with stroke risk and overall health.

A stroke can be scary and it can happen in someone who appears to be healthy.

Knowing the warning signs and getting emergency medical attention is the most important thing if a stroke is suspected.

People should not drive the affected individual to the hospital. Instead, they must call an ambulance so that paramedics can provide medical attention as quickly as possible.

They can also take the person to the hospital who can provide the best stroke care, which is not always the closest facility.