Cerebral aneurysm: what it is, causes and symptoms. Is there a cure?

You may have heard of a brain aneurysm . The condition is silent until the last moment and, when it finally breaks – its worst result -, it draws attention for the speed with which it manifests itself, which can lead to death.

Many people, despite having heard about it, cannot say what a cerebral aneurysm is. Keep reading to learn more about the condition


What is cerebral aneurysm?

An aneurysm occurs when the walls of an artery are weakened and, in these cases, the affected region tends to become dilated.

They can occur in different regions of the body, but those that occur in the brain region (cerebral aneurysms) are noteworthy because, when they break, they lead to a rapid death that apparently appears out of nowhere.

Aneurysms tend to happen at bifurcations of the arteries (where an artery splits into two, being a more fragile structure), they are more frequent in women and are common to affect people over 45 years of age.

Approximately 5% of the population has brain aneurysms, but most never discover them, and in these patients, they do not cause problems, because the symptoms only appear if there is a disruption.

In general, it occurs when the region, already weakened, is under pressure due, for example, to stress , agitation or medication, and breaks up.

When aneurysms are small, the risk of rupture is low, but when they are large or grow, it is important to treat the situation urgently.

The rupture of an aneurysm in the brain is a medical emergency and most often causes subarachnoid hemorrhage .

Blood leaks into the region below the arachnoid, a protective layer of the brain. Approximately 30% of patients who have a ruptured aneurysm die and, among others, most suffer from sequelae.

When the rupture occurs, blood from the artery leaks into the brain and destroys cells by means of pressure or, in cases where it is able to come into direct contact with brain tissue, by natural chemistry.

Depending on the amount of blood and the affected region, there is nothing that can be done and the patient dies.

Types of aneurysm

Aneurysms affect arteries, which are responsible for carrying oxygen-rich blood to the body.

They are not exclusive to the brain and can occur in any artery in the body, the most common regions being the aorta and the brain.

Although brain aneurysms can occur anywhere in the brain, most of them occur at the base of the skull, in the so-called Willis Polygon, a set of arteries that carry blood to the brain.

There are a few different types of aneurysms. Are they:

aneurysm sacular

The saccular aneurysm forms a small pocket in the artery, in the region where the arterial wall is weakest. The bag has the appearance of a bladder and the pressure exerted by the bloodstream can cause it to expand over time.

The expansion of a cerebral aneurysm can have two negative consequences: the rupture of the bag and the compression of areas of the brain.

Compression is more rare, as for this to happen, the blood bag needs to grow considerably.

There are cases where a single person has several saccular aneurysms. This is usually linked to a genetic tendency.

Aneurisma fusiforme

The fusiform aneurysm does not create a pocket. In this case, the walls of an artery are weakened across the circumference of a certain arterial region, which causes it to swell differently and more uniformly.

Dissecting aneurysm

A dissecting aneurysm is much more frequent in the aorta (the largest artery in the body) than in the brain, but it is also possible. It usually happens due to injuries, but it can also be spontaneous.

In this case, an injury causes one of the layers of the arterial wall to detach and blood can penetrate that opening. Rather than happening as in the other two cases, the arterial wall does not necessarily need to be weakened.

When this happens, blood accumulates within the arterial walls. The result, as in other cases, is the same and the pressure can cause the artery to rupture.


There are some causes for the formation of aneurysms. Among the main ones are:


Aneurysms can be a genetic characteristic that manifests itself as the presence of arterial regions where the walls are naturally thinner, which favors the appearance of the condition.

If you have a case in the family, it may be interesting to go to the doctor for tests and find out if you don’t have one.

The cases of multiple aneurysms are usually related to genetics and are characterized when the patient has several aneurysms at the same time.


Although rare, brain aneurysms caused by injuries are possible. They can come from accidents, trauma, blows or surgery, for example.

Brain aneurysm symptoms

The symptoms of a cerebral aneurysm usually appear only when it breaks or leaks and when it puts pressure on the brain region, but this is rare because the aneurysm needs to be quite large.

The symptoms of the rupture are similar to that of a hemorrhagic stroke (stroke) in that it is exactly what happens: the leakage of blood from within the vascular system to the brain.

But in most cases the aneurysm is silent and that is why it is usually diagnosed during tests that look for other things. However, the symptoms when it breaks are as follows:


When the brain aneurysm ruptures, it causes a very severe headache and many patients who survived reported it was the worst headache of their life.

It is often called a “thunderstorm headache” as it is extremely strong, suddenly and instantly already in its peak of pain, and may even cause imbalance and falls.

The aneurysm-related headache is not always a thunderstorm, but it is common and usually associated with the condition.

Sensitivity to light

Soon after the pain, a great sensitivity to light can appear. The stronger this sensitivity, the more severe the aneurysm.

Vomiting and nausea

Both high pressure in the brain and damage from leaking blood can cause severe vomiting and nausea.


Lethargy, or tiredness , is a common symptom when the aneurysm ruptures and it is necessary to pay attention, as it can intensify and lead to a coma. Like sensitivity to light, the stronger this symptom, the more severe the condition.

Neck stiffness

Similar to meningitis , cerebral aneurysm can cause stiff neck. This is because blood leaking through the artery accumulates in the region and increases intracranial pressure.


Seizures , which are abnormal electrical activities in the brain, can happen as a result of cerebral hemorrhage, as damage to neurons, caused by blood in the region, can lead to electrical problems in them.


Brain damage from blood can manifest itself in the form of severe confusion. It is important that the patient goes to the hospital as soon as possible so that emergency care is performed.

Neurological problems

Difficulty in speech, movement, paralysis of certain regions of the body and other neurological problems can arise after the rupture of an aneurysm, resulting from the damage caused by blood in the brain.

Is cerebral aneurysm curable?

-Yeah . If it is found before it breaks, it is possible to perform some procedures that prevent it from causing problems. When it ruptures, the chances of survival drop dramatically, but it is still possible for emergency surgery to stop the bleeding.

Risk factors

Some people are at increased risk of developing aneurysms. The factors that increase the chances are:

High pressure

The high pressure can, over time, weaken certain areas of the blood system and the most sensitive areas of these effects are arterial bifurcations.

When they weaken, the same pressure that caused this effect causes them to dilate and swell, forming the aneurysm.

High blood pressure, in addition to increasing the chances of the condition arising, also increases the chances of it breaking.


The Atherosclerosis is a condition characterized by the formation of fatty plaques in the arteries. This can increase blood pressure, block the region or cause arterial dilation, causing the walls to weaken, which in turn leads to aneurysms.

Although this condition is more often related to cardiac aneurysms, it can also lead to the brain.


With age, the arterial walls weaken naturally. This can favor the formation of aneurysms, in addition to the growth and rupture of existing ones.

Therefore, as a person ages, it is recommended that you visit the doctor frequently for routine examinations.

From 45 years of age it is important to have regular examinations to find out if there are aneurysms, or if small aneurysms have increased.

Family history

People who have family members with a history of aneurysm are more likely to have the condition. If a family member of yours has already been diagnosed, it may be a good idea to seek tests.


Tobacco has numerous health hazards. Among them, the increased fragility of the arteries, which increases the chances that aneurysms will appear or burst.

Smoking is bad for you and increases your chances of having countless problems ranging from famous lung cancers, heart problems and aneurysms.

Read more:  What is smoking, causes, treatment, diseases and consequences


Diabetes patients are more likely to develop aneurysms anywhere on the body, so, especially after the age of 45, it is very important to visit the doctor frequently.

Read more:  Medical detection dogs: best friend for people with diabetes


Frequent drinking of alcoholic beverages is also a risk factor for the development of brain aneurysms, in addition to increasing the chances of them breaking. So drink in moderation.


Certain drugs can increase the chances of the development and rupture of aneurysms. Among them, there is especially cocaine , which causes an increase in heart rate and can bring serious health problems.

How is the diagnosis made?

Usually brain aneurysms do not cause symptoms, unless they are very large.

As long as they do not rupture, blood usually passes through the artery normally, which means that it is rare for anyone to see a doctor with suspected aneurysms.

Therefore, it is common for the condition to be found as a result of tests that look for other problems.

The professionals who diagnose brain aneurysms are the neurologist , the general practitioner and the angiologist . The tests that can be done to reveal aneurysms are imaging tests such as:

Cerebral angiography

Angiography is the main test used to detect problems in the circulatory system.

During this procedure, a liquid is injected into the vascular system. This liquid is called contrast and appears clearly on X-ray exams , which allows the doctor to observe the blood vessels in detail.

The aneurysm is very evident and the changes – such as dilation or the bag – caused by the aneurysm appear there.

Magnetic resonance imaging

Magnetic resonance imaging uses magnets and radio waves to generate a 3D image of the body, in great detail. It can be used to find brain injuries with tremendous precision.

The magnetic resonance angiography uses the same equipment, calibrated to the patient’s own blood as there is contrast. This allows the cerebral vascular system to be visible to the medical professional and there is no need to inject substances.

It is extremely accurate, just like angiography, but it is less invasive and faster than the previous exam.

Computed tomography

Computed tomography uses X-ray to make a complete image of all or part of the body. In the case of cerebral aneurysm, it is done on the head.

It is usually used to find tumors or objects inside the head, so it is effective for finding aneurysms.

Contrast is also used in this image exam.


The treatment for cerebral aneurysms, when necessary, is surgical. There are two surgeries that can be performed to protect the patient from possible disruption. Are they:


Aneurysm clipping is a method that can be used both to prevent the aneurysm from rupturing and to prevent an already ruptured one from causing further damage.

The procedure requires open brain surgery.

The neurosurgeon finds the aneurysm and uses a metal clamp to block it, ensuring that blood flow remains normal in the artery, but stops going to the aneurysm.

When the rupture has already occurred, the doctor can wash the area affected by the blood, but the damage that has already happened, in most cases, cannot be reversed.


Aneurysm embolization is a less invasive method, which avoids opening the skull, and which only works when performed on an aneurysm that has not yet ruptured.

The procedure uses a catheter that is inserted close to the patient’s groin or arm region and goes through the circulatory system to the aneurysm in the brain.

stent is a tiny expandable grid, which is taken through a catheter to the desired artery to assist in its structure (making way for the blood when it is blocked by cholesterol, for example).

In the case of an aneurysm, the stent lodges with the artery and the aneurysm is left out. The next step is embolization .

For this, after placing the stent, through the same path, the doctor inserts a small tube that is placed inside the aneurysm and discharges a special type of glue or metal springs.

The stent prevents the glue or springs from leaking into the rest of the artery and it is confined to the aneurysm.

The material accumulates blood, which coagulates. The clot closes the aneurysm and the blood stops entering it, ceasing to apply pressure and preventing it from rupturing.

How is recovery from surgery?

It depends. Several situations can affect the level of difficulty of the operation, in addition to the type of procedure also modifying the recovery.

After clipping, there is expected to be some headache. In addition, it is a dangerous surgery since the doctor needs to work on the brain to find the artery and perform the clipping. There may be complications related to it.

A lot of rest is recommended after an intracranial surgery.

In the case of embolism, recovery is simpler. The procedure is much less invasive since the skull does not need to be opened and it is possible that the patient will be discharged in a short time.


The prognosis of an aneurysm rupture is not usually positive. Approximately 12% of Brazilians with ruptured intracranial aneurysms die before having medical treatment. 40% die after a month of breaking up.

If the aneurysm is not treated before the rupture, the result tends to be death or sequelae. Rarely does the patient fully recover.

The sequelae can cause serious problems and reduce the patient’s quality of life and, therefore, it is important that tests are performed frequently, especially in cases of patients with risk factors.

The main prognostic indicators are the region where the aneurysm is located and the amount of blood that flows from the artery to the brain.

Living together

Living with an aneurysm depends on whether it has already burst or not. If you have an unbroken aneurysm, it is best to ask your doctor for his opinion. He may decide that the risk of rupture is not high enough to warrant surgery.

In this case, his follow-up is indicated. Regular checkups for signs that it may break or if it is growing should be done.

Care must be taken to prevent breakage: avoid smoking, drinking, control your diet, stay away from drugs.

However, if an aneurysm has ruptured, the patient is likely to have sequelae.

The treatment of sequelae may require a multidisciplinary team composed of neurologists , neuropsychologists , occupational therapists , physiotherapists , speech therapists and other professionals, depending on the extent of the sequelae.

Complications: can cerebral aneurysm cause sequelae?

Complications of cerebral aneurysm occur when there is a rupture, resulting in blood leakage that damages brain tissue. The main complications are:

Increased intracranial pressure

The blood that flows into the brain outside the arteries can increase the pressure inside the skull. This can cause damage to brain cells, with serious consequences and even death.


Brain cells, when in direct contact with large amounts of blood, die. Depending on the region of the brain that is affected, parts of the body may have reduced movement or even become completely paralyzed.

In addition, the ruptured artery may contract in an attempt to prevent blood leakage. This can prevent blood from reaching certain regions of the brain where that artery was taking it, causing cell death due to lack of oxygen.


Bleeding within the brain can result in accumulations of cerebrospinal fluid (fluid that nourishes and protects the organ). This is the condition called hydrocephalus . Basically, the condition is an accumulation of fluid that increases brain pressure, which can cause severe damage.


Blood, in direct contact with brain cells, can remove sodium from them. This causes the cells to fail to function properly, which can eventually lead to cell death.


The electrical activity of the brain can change with bleeding, resulting in seizures, which in turn can be very dangerous.

Loss of brain functions

Damage from an aneurysm rupture can cause brain cells to die, which in turn leads to the loss of certain brain functions. The sequelae can be motor, nervous or intellectual.

Difficulties in movement, loss of memory, dysregulation of emotions and other consequences can arise.


Depending on the size of the affected region, the patient may go into a coma, which is often followed by death.


Death occurs in most cases of ruptured aneurysms and it is not uncommon to happen too quickly for anything to be done. Therefore, it is important that the diagnosis of cerebral aneurysm is made quickly.


Prevention is the best medicine against brain aneurysms. With these precautions, you reduce the chances of an aneurysm appearing and breaking.

Do not smoke

Smoking increases the chances of problems with aneurysms, in addition to bringing several other health risks.

Do not drink

Alcohol, especially if ingested in large quantities or very often, puts people at risk for the development and rupture of aneurysms, which can cause serious problems.

Eat well

Food is essential to reduce the chances of health problems. Avoid foods with too much sodium or too many fats, as exaggerations of these substances weaken the circulatory system, which in turn increases the chance of aneurysms.

Take care of blood pressure

If you have high blood pressure, be careful with it. Listen to your doctor and try to keep the pressure at an appropriate level. High pressure can cause aneurysms to form and rupture.

Take care of stress

Stress can cause the pressure to increase, which can cause a brain aneurysm to rupture.

Regular exams

From 45 years of age, have regular check-up exams. Because brain aneurysms rarely show symptoms before they rupture, prior investigation is the only way to find it.

Common questions

At what size is an aneurysm dangerous?

Size is not the only measure to define how dangerous an aneurysm is. It is true that the bigger it is, the greater the chances of it breaking up. But the region where it is located, as well as the blood flow within it, are equally important.

An irregular blood flow inside the aneurysm increases the chances of rupture, for example.

Do aneurysms always kill?

No . When a brain aneurysm ruptures, it is extremely dangerous and it is common that, if there is no rapid treatment, it will lead to death, but there are cases in which it brings only brain complications.

Can I live with an aneurysm?

-Yeah . Many people spend their entire lives with an aneurysm and never discover that it is present. Even though approximately 5% of the population has the condition, most never face problems because of it.

However, remember that your doctor is the professional who can tell you whether an aneurysm is safe or needs to be operated on.

Is there a headache after surgery?

Headache after brain aneurysm clipping surgery is to be expected, but remember to follow your doctor’s recommendations and report any symptoms you have.

Is it possible to have more than one aneurysm?

-Yeah . Multiple aneurysms are usually related to genetic causes. Depending on their size, they may need surgery.

Cerebral aneurysm is a serious condition and when it ruptures, it is a medical emergency. 30% of patients with a ruptured aneurysm die and most of those who survive suffer sequelae.

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