Brain Aneurysm

A brain aneurysm is a bulge or ballooning in a weakened blood vessel in the brain. While many brain aneurysysms remain small and cause no symptoms, a ruptured brain aneurysm can lead to sudden, life-threatening bleeding and requires immediate emergency treatment.

Understanding the symptoms of a brain aneurysm, the possible cause of brain aneurysm, and available brain aneurysm treatment options is essential for early diagnosis and timely care. In this Health Guide, we explain what a cerebral aneurysm is, why it develops, how it is diagnosed, and which treatment approaches may be recommended.

What is a Brain Aneurysm?

A brain aneurysm, also known as a cerebral aneurysm or intracranial aneurysm, is a localized bulge that develops in a weakened section of an artery in or around the brain.

Over time, the constant pressure of circulating blood pushes against the fragile area of the artery wall. This pressure causes the vessel to stretch outward, forming a blister-like swelling. As blood continues to flow into this bulge, the aneurysm wall may become thinner and more vulnerable to leaking or rupture.

Brain aneurysms most commonly form in the major arteries located at the base of the skull. Approximately 10% to 30% of individuals with a brain aneurysm have multiple aneurysms.

Most brain aneurysms:

• Are small

• Do not rupture

• Do not cause noticeable symptoms

• Are discovered incidentally during MRI or CT imaging performed for another medical reason

However, if an aneurysm enlarges, leaks, or ruptures, it becomes a medical emergency that requires urgent evaluation and treatment.

What Happens When a Brain Aneurysm Ruptures?

A brain aneurysm rupture occurs when the weakened blood vessel bursts, causing bleeding in or around the brain.

In most cases, rupture leads to subarachnoid hemorrhage, which is bleeding into the space between the brain and the thin protective tissues covering it. In fact, about 90% of subarachnoid hemorrhage cases are caused by ruptured brain aneurysms.

When rupture occurs:

• Blood leaks into surrounding brain tissue

• Pressure inside the skull increases

• Brain swelling may develop

• Oxygen delivery to brain tissue may decrease

A ruptured brain aneurysm can lead to serious complications, including:

• Subarachnoid hemorrhage

• Hemorrhagic stroke

• Vasospasm (narrowing of brain blood vessels)

• Hydrocephalus (fluid buildup around the brain)

• Seizures

• Coma

• Permanent neurological damage

• Death

Roughly 50% of ruptured brain aneurysms are fatal. The risk of death or long-term disability increases the longer treatment is delayed.

Types of Brain Aneurysms

Brain aneurysms are classified based on their shape and size.

Saccular (Berry) Aneurysm

This is the most common type. It appears as a small, round sac attached to an artery by a narrow neck. Most ruptured brain aneurysms are saccular.

Fusiform Aneurysm

In this type, the artery bulges outward on all sides. Instead of forming a small sac, the entire vessel segment expands.

Dissecting Aneurysm

This type occurs when a tear develops in the inner layer of the artery wall, allowing blood to enter and separate the layers of the vessel.

Classification by Size

Aneurysm size plays an important role in rupture risk:

• Small: Less than 5 mm

• Medium: 5–15 mm

• Large: 15–25 mm

• Giant: Larger than 25 mm

Larger and irregularly shaped aneurysms generally carry a higher risk of rupture.

Brain Aneurysm Symptoms

The symptoms of a brain aneurysm vary depending on whether the aneurysm is unruptured, leaking, or fully ruptured.

Symptoms of a Ruptured Brain Aneurysm

A ruptured aneurysm is a medical emergency. The most common symptom is a sudden, severe headache. This is known as a thunderclap headache because it reaches peak intensity within seconds.

Other symptoms may include:

• Nausea and vomiting

• Stiff neck

• Blurred or double vision

• Sensitivity to light (photophobia)

• Seizures

• Drooping eyelid

• Dilated pupil

• Pain above or behind the eye

• Confusion

• Weakness or numbness

• Loss of consciousness

If these symptoms occur, emergency services should be contacted immediately.

Sentinel (Warning) Headache

In some cases, a small leak called a sentinel bleed may occur days or weeks before a major rupture. This can cause a sudden but less severe warning headache.

Symptoms of an Unruptured Brain Aneurysm

Most unruptured brain aneurysms do not cause symptoms. However, larger aneurysms may press on nearby nerves or brain tissue and lead to:

• Persistent headaches

• Vision changes

• Enlarged pupil

• Facial numbness or tingling

• Pain behind the eye

• Seizures

If you experience these symptoms, you should consult a healthcare provider promptly.

Causes and Risk Factors for Brain Aneurysms

The main cause of brain aneurysm formation is weakness in the artery wall. Aneurysms commonly develop at branching points of arteries where blood flow pressure is strongest.

Genetic and Inherited Conditions

Certain inherited disorders increase the risk of developing brain aneurysysms, including:

• Vascular Ehlers-Danlos syndrome

• Autosomal dominant polycystic kidney disease

• Marfan syndrome

• Fibromuscular dysplasia

• Arteriovenous malformations

Having a first-degree relative (parent or sibling) with brain aneurysms also increases risk.

Lifestyle and Medical Risk Factors

Several acquired conditions can weaken artery walls over time:

• Smoking

• High blood pressure

• Substance abuse

• Excessive alcohol consumption

• Chronic uncontrolled stress

What Causes a Brain Aneurysm to Rupture?

The same factors that contribute to aneurysm formation can also increase rupture risk.

High blood pressure is considered one of the most significant triggers of rupture. Situations that suddenly raise blood pressure may increase the risk, such as:

• Heavy lifting or straining

• Intense emotional stress

• Untreated hypertension

Other factors influencing rupture risk include:

• Larger size

• Irregular shape

• Documented growth

• Location in certain arteries

• Age over 70

• Multiple aneurysms

• Previous aneurysm bleed

Diagnosis of Brain Aneurysms

Many unruptured brain aneurysms are discovered incidentally during imaging tests performed for unrelated reasons.

If a ruptured aneurysm is suspected, emergency imaging is required.

CT Scan

A CT scan is usually the first imaging test performed in emergency settings. It can quickly detect bleeding in the brain.

A CT angiogram (CTA) provides more detailed images of blood vessels and helps determine the size and location of an aneurysm.

MRI and MRA

MRI produces detailed images of brain tissue.

Magnetic resonance angiography (MRA) focuses specifically on blood vessels and can help evaluate aneurysm size and shape.

Cerebral Angiography

Cerebral angiography is considered the gold standard for diagnosing brain aneurysms. During this procedure:

• A catheter is inserted through the groin or wrist

• It is guided to the brain arteries

• Contrast dye is injected

• Detailed vessel images are obtained

This test provides precise information to guide treatment planning.

Lumbar Puncture

If imaging does not clearly show bleeding but suspicion remains high, a lumbar puncture may be performed to detect blood in the cerebrospinal fluid.

Treatment Options for Brain Aneurysms

The primary goal of treatment brain aneurysm strategies is to stop blood flow into the aneurysm and prevent rupture or re-rupture.

Treatment decisions depend on:

• Aneurysm size and location

• Ruptured or unruptured status

• Patient age and general health

• Overall rupture risk

Surgical Clipping

Surgical clipping is a traditional open surgical method.

During this procedure:

• A small opening is made in the skull

• A metal clip is placed at the base of the aneurysm

• Blood flow into the aneurysm is blocked

Clipped aneurysms rarely recur.

Recovery time:

• 2–4 weeks for unruptured aneurysms

• Several weeks to months for ruptured aneurysms

Aneurysm Coiling

Aneurysm coiling is a minimally invasive endovascular procedure.

A catheter is inserted through the groin or wrist and guided to the aneurysm. Tiny platinum coils are placed inside the aneurysm, promoting clot formation and preventing blood from entering.

This method avoids open brain surgery and typically involves a shorter hospital stay.

Flow Diversion Stents

A mesh-like stent is placed inside the affected artery to redirect blood flow away from the aneurysm, allowing the vessel wall to heal over time.

WEB Device

A specialized mesh device is placed inside the aneurysm to block blood entry and reduce rupture risk.

Additional Care for Ruptured Brain Aneurysm

In cases of rupture, intensive care management may include:

• Antiseizure medications

• Calcium channel blockers to reduce vasospasm

• Shunt placement for hydrocephalus

• Close neurological monitoring

Rehabilitation may involve physical therapy, speech therapy, and occupational therapy.

Preventing Brain Aneurysms and Reducing Risk

Although not all aneurysms can be prevented, lifestyle changes can significantly reduce risk.

Control Blood Pressure

Maintaining healthy blood pressure through medication and lifestyle changes is essential.

Stop Smoking

Smoking significantly increases both aneurysm formation and rupture risk.

Avoid Substance Abuse

Avoid drugs and limit alcohol consumption.

Regular Monitoring

If you have a family history of brain aneurysms, screening may be recommended.

Life After Brain Aneurysm Treatment

Recovery and long-term outlook depend on whether the aneurysm ruptured and how quickly treatment was received.

Prognosis After Rupture

• About 25% of patients die within 24 hours

• Around 50% die within three months

• Approximately two-thirds of survivors experience some permanent neurological effects

However, some patients recover with little or no long-term disability.

Living with an Unruptured Brain Aneurysm

Many people live long, healthy lives with small unruptured aneurysms that never cause complications. Regular follow-up imaging and careful blood pressure management are important.

Ongoing Follow-Up

Patients who have had a ruptured aneurysm or multiple aneurysms require long-term monitoring to reduce recurrence risk.

When Should You Seek Medical Care?

Call emergency services immediately if you experience:

• Sudden severe headache

• Vision problems

• Seizures

• Confusion

• Loss of consciousness

Early diagnosis and rapid treatment significantly improve survival rates.

Brain Aneurysm Care in Turkey at Medical Park

Brain aneurysms require precise diagnosis, advanced imaging technologies, and the expertise of experienced neurosurgical and interventional teams. At Medical Park Hospitals in Turkey, patients benefit from a comprehensive, multidisciplinary approach that brings together expert neurology, neurosurgery, and interventional radiology specialists to ensure accurate evaluation and timely treatment.

Depending on the patient’s condition, treatment options may include surgical clipping, aneurysm coiling, and advanced endovascular techniques tailored to the aneurysm’s size, shape, and location.

Early detection, individualized treatment planning, and structured long-term follow-up play a crucial role in reducing complications and improving outcomes for patients diagnosed with brain aneurysms.