Having a stroke is a life-changing experience, as a person will not have the same skills
or even personality after a stroke.
This is because a stroke damages one of the most important organs in our body –
the brain.
What is going on in the brain during a stroke?
Tune in to this episode of Medicurio where we will discuss detection, prevention, and
treatment of one of the most common and debilitating diseases in our society.
All of the cells in our body need oxygen, as well as other nutrients such as sugar,
to work and survive.
For cells that are constantly using energy, such as the neurons in the brain, they need
a constant supply of oxygen to keep working.
This cellular fuel is delivered to cells by blood; therefore, if something stops the blood
flow to cells, these cells essentially starve to death.
Lack of oxygen can lead to death of neurons within minutes.
This is known as a cerebral infarction, or a stroke.
Since neurons rarely regenerate, their death often leads to irreversible brain damage.
Therefore, it is crucial to send someone to a hospital to be treated immediately after
the symptoms of a stroke are observed.
Remember FAST: F for face – check if one side is drooping.
A for arms – see if one arm cannot be raised as high as the other one.
S for speech – listen for slurring or even an inability to speak.
And T for time – get them to the hospital right away.
The longer a person does not get treated, the more parts of the brain will become permanently
damaged, leading to lifetime disability or even death if neurons responsible for life
processes, such as breathing, are affected.
So how is blood flow to the brain disrupted?
There are two ways for a stroke to occur depending on how blood flow is stopped – either the
blood vessels become clogged or they rupture and bleed out.
The most common type of stroke is an ischemic stroke, in which blood vessels are blocked.
Usually this occurs in one of the two carotid arteries
that each supply half of the brain with blood.
This also explains why stroke symptoms are often only present on one side, such as face
drooping or arm weakness, because the half of the brain that controls that side is dying.
Blockage can also happen in arteries within the brain.
So how do blood vessels become blocked?
When the walls of arteries are damaged, such as due to high blood pressure, high blood
cholesterol, or high blood sugar, layers of cholesterol, fats, and immune cells can build
up on the walls to form plaques.
Sometimes, these plaques can break apart, exposing a surface that makes it easy for
a blood clot, or thrombus, to form.
Eventually, a blood clot can get big enough to completely block the blood vessel and the
neurons that are supported by that blood vessel are deprived of oxygen.
This is known as a thrombotic stroke and is the most common type of ischemic stroke.
On the other hand, a blood clot does not have to form within the brain to cause a stroke.
Blood clots that form elsewhere in the body can break apart and get pumped into the brain,
where they get stuck in the narrower blood vessels.
Pieces of plaque can also detach and do the same thing.
This causes a type of ischemic stroke known as an embolic stroke because these detached
blood clots and plaques are known as emboli.
This occurs most often in people with atrial fibrillation, which means they have an irregular
heartbeat.
Since the blood is pumped poorly throughout the body, blood can pool and clot within the
heart, then move into the brain to block smaller arteries.
Sometimes, stroke symptoms only last for a few minutes and then disappear on their own
without any significant brain damage, which is known as a transient ischemic attack or
TIA.
Even though the symptoms disappear quickly, still call for an ambulance immediately and
go to the hospital because a TIA is a clear warning sign – 1 in 3 people who experience
a TIA end up suffering from an actual stroke within a year.
A TIA occurs when a blood clot blocks an artery
but is quickly broken down by natural anticoagulants found in our body.
The less common but more deadly type of stroke is a hemorrhagic stroke,
in which blood vessels within the brain burst.
This redirects blood away from neurons, depriving them of oxygen.
In addition, since the skull does not expand, any blood that flows out will begin compressing
the brain, which can also lead to irreversible brain damage and even death.
Hemorrhagic strokes are usually due to high blood pressure, which pushes against and stretches
the walls of blood vessels to weaken them,
forming brain aneurysms that are prone to rupture.
Treatment for strokes will be different depending on whether it is ischemic or hemorrhagic.
For ischemic strokes, the primary method is to remove the clot.
This can be done by various medications that break down the clot, such as tissue plasminogen
activator, or a surgical removal process known as mechanical thrombectomy.
On the other hand, a hemorrhagic stroke almost always requires surgery to repair the damaged
blood vessel and relieve pressure in the brain from the leaked blood.
Doctors usually do a brain scan to determine the type of stroke and its proper treatment,
as an anticoagulant is great to break down clots in an ischemic stroke, but will make
bleeding worse in a hemorrhagic stroke.
Recovering from a stroke is often difficult.
Since different parts of the brain control different things, depending on which part
of the brain was damaged during the stroke, a person could have problems walking or moving,
controlling emotions, speaking, making new or remembering old memories,
seeing, or feeling sensations.
Some may have a completely different personality, while others fall into depression.
These problems can be so severe that three quarters of stroke survivors are unable to return to
the workforce.
Thankfully, there are amazing doctors, nurses, therapists, psychologists, and support groups
to help the recovery process.
Additionally, anticoagulants such as aspirin can be used to prevent another ischemic stroke
from occurring by making it difficult for blood to clot.
However, it is best if you never have a stroke in the first place.
In fact, 80% of strokes are preventable.
Since high blood pressure, cholesterol, and sugar can lead to plaques and eventually blood
clots, while high blood pressure can also lead to ruptures, targeting those risk factors
is a step in the right direction in stroke prevention.
There are many medications available to lower these three parameters, but the best method
is to eat a healthy diet and exercise often.
Other risk factors include smoking, heavy alcohol use, and drug abuse, which should
be avoided as they not only increase the risk of stroke
but a variety of other diseases as well.
Stroke seems to have a genetic component and is 25% more likely to occur in men.
And finally, having a stroke or a TIA makes it much more likely that a stroke will occur
in the future if medication is ignored and lifestyles are not changed.
Every year, around 15 million people worldwide will have a stroke.
Of these 15 million, a third will pass away and another third will have a disability for
the rest of their life.
In fact, stroke is the second leading cause of death in the elderly
and fifth in middle-aged people.
But with proper lifestyle choices and knowledge of this disease, you can prevent a stroke
from happening to yourself, or even realize that someone else is having a stroke to save
their life.
Of course, if you would like to contribute to finding more effective ways of treating
and preventing stroke, check out the links in the description below.
Feel free to share any personal stories about stroke in the comments below – after discussing
the science behind a disease, it is very easy to forget that there is also a human aspect.
Thanks for watching, and see you next time on Medicurio.