Stroke: What is it? Symptoms, Risk Factors, Causes and Treatment

A stroke is a medical emergency because strokes can cause death or permanent disability.

A stroke, also known as stroke , is when part of the brain loses its blood supply and the part of the body of brain cells deprived of blood stops working.

This loss of blood supply can be ischemic due to lack of blood or hemorrhagic flow due to hemorrhage in brain tissue.

There are opportunities to treat ischemic strokes, but that treatment should be started in the first hours after the signs of a stroke begin.

The patient, family or bystanders should call the doctor and activate emergency medical services immediately in case of suspicion of a stroke.

A transient ischemic attack (TIA or mini-stroke) describes a short-term ischemic stroke where the symptoms resolve spontaneously.

This situation also requires an emergency evaluation to try to minimize the risk of a future stroke.

By definition, a stroke would be classified as a TIA if all symptoms were resolved within 24 hours.

What is the NIH Stroke Scale?

Not all strokes affect the brain equally, and the symptoms and signs of stroke depend on the part of the brain affected.

For example, the center of speech for most people is in the left half of the brain, so a stroke affecting the left side of the brain would affect speech and comprehension.

It would also be associated with the weakness of the right side of the body.

A right stroke would weaken the left side of the body. And depending on where in the brain the injury occurred, the weakness could be the face, arm, leg or a combination of all three.

The NIH Stroke Scale tries to rate how severe a stroke can be.

It also monitors whether the person’s stroke is getting better or worse as time goes by as the patient is reexamined.

There are 11 categories that qualify and include if the patient:

  • Is awake.
  • You can follow commands.
  • Can see.
  • You can move your face, arms and legs.
  • Has normal bodily sensations or feelings.
  • He has speech difficulties.
  • He has coordination problems.

What are the signs and symptoms of a stroke?

The symptoms of a stroke depend on which part of the brain has stopped working due to the loss of your blood supply.

Often, the patient may have multiple symptoms, including the following:

  • Sharp change in the level of consciousness or confusion.
  • Weakness or paralysis of the half or part of the body.
  • Loss of partial vision
  • Double vision.
  • Difficulty speaking or understanding speech.
  • Difficulty with balance and vertigo .

The symptoms of ischemic and hemorrhagic stroke may be the same, but patients with hemorrhagic stroke may also present more headache and vomiting.

What are the risk factors for stroke?

In general, the most common risk factors for stroke are:

  • High blood pressure
  • High cholesterol.
  • Smoke.
  • Diabetes.
  • Increase in age

Cardiac conditions such as atrial fibrillation, patent foramen ovale, and heart valve disease may also be the potential cause of stroke.

When stroke occurs in younger individuals (less than 50 years old), the least common risk factors that should be considered include illicit drugs.

Like cocaine or amphetamines, broken aneurysms and hereditary (genetic) predisposition to abnormal blood clotting.

An example of a genetic predisposition to a stroke occurs in a rare condition called homocystinuria , in which there are excessive levels of the chemical homocystin in the body.

Scientists are trying to determine if the non-hereditary occurrence of high levels of homocystin at any age can predispose to stroke.

What causes a stroke?

Blockage of an artery in the brain by a clot ( thrombosis ) is the most common cause of a stroke. The part of the brain that is supplied by the clotted blood vessel is deprived of blood and oxygen.

As a result of the deprivation of blood and oxygen, the cells of that part of the brain die and the part of the body that controls stops working.

Usually, a cholesterol plaque in one of the small blood vessels of the brain breaks down and starts the clotting process.

The risk factors for narrowed blood vessels in the brain are the same that cause narrowing of blood vessels in the heart and heart attack (myocardial infarction).

These risk factors include:

  • High blood pressure ( hypertension ).
  • High cholesterol.
  • Diabetes.


Endovascular procedures can be used to treat certain hemorrhagic strokes similar to the way in which the procedure is used to treat an ischemic stroke.

These procedures are less invasive than surgical treatments and involve the use of a catheter introduced through a main artery in the leg or arm, and then are guided to the aneurysm or  AVM; then deposit a mechanical agent, such as a coil, to prevent rupture.

Surgical treatment

For strokes caused by bleeding inside the brain (hemorrhagic stroke) or by abnormal blood vessel entanglement (AVM), surgical treatment can be performed to stop bleeding.

If the bleeding is caused by a ruptured aneurysm (swelling of the ruptured vessel), a metal clip can be surgically placed on the base of the aneurysm to secure it.