Brain aneurysm – how common is it and how can it be detected?

What is a cerebral aneurysm?

A cerebral aneurysm is a bulge in the wall of a cerebral artery. It develops when the wall of the blood vessel weakens and a small dilation forms.
Most often, an aneurysm is small and causes no symptoms. Many people are unaware that they have an aneurysm because it does not necessarily affect their well-being in any way.

Studies indicate that cerebral aneurysms occur in about 2–3 percent of the population, meaning that a few people out of every hundred may have this type of vascular change without it ever causing symptoms.

How common are aneurysms in Finland?

Cerebral aneurysms have been extensively studied in Finland, and Finnish data has been of significant international importance.

Compared to other countries, there are slightly more aneurysms and related hemorrhages in Finland. The reasons for this are not fully understood, but possible contributing factors include:

• genetic factors
• high blood pressure
• smoking

A Finnish study has found that aneurysms may occur more frequently than average in certain risk groups, such as middle-aged women who smoke.

What symptoms can a brain aneurysm cause?

Most aneurysms do not cause symptoms and are often discovered by chance during imaging tests.

A growing aneurysm can sometimes cause:

• headaches
• visual disturbances
• double vision
• symptoms caused by nerve compression

The most serious situation is a ruptured aneurysm, which leads to a brain hemorrhage.

How often do aneurysms rupture?

Although aneurysms are relatively common in the general population, only a small proportion rupture during a person’s lifetime. Most aneurysms remain asymptomatic throughout a person’s life.
The risk of rupture depends on factors such as the size and location of the aneurysm, as well as individual factors. For this reason, not all aneurysms are treated; some are monitored regularly.

What factors increase the risk of a brain aneurysm?

Several factors can increase the risk of an aneurysm:

• high blood pressure
• smoking
• family history of aneurysms
• age
• certain connective tissue disorders

Often, the development of an aneurysm is influenced by a combination of factors, and no single cause is decisive.

When is brain imaging typically considered?

Brain imaging may be considered in situations where more detailed information about symptoms or risk factors is needed. In most cases, a doctor assesses the need for imaging on a case-by-case basis.

Typical situations include:

• prolonged or unusual headaches
• vision or balance problems
• symptoms related to nervous system function
• family history of aneurysms

Imaging can also be used for follow-up if changes have been detected in previous examinations.

How can a brain aneurysm be detected?

Today, aneurysms can be examined in detail using magnetic resonance imaging (MRI). MRI provides detailed information about the structure of the brain and blood vessels without radiation.
In particular, magnetic resonance angiography (MRA) allows for the examination of blood vessels and can reveal the size and location of an aneurysm.

Who interprets brain MRI scans?

Brain imaging requires specialized expertise. At Visio MRI, a neuroradiologist—a specialist in radiology—always interprets MRI scans of the head and brain.
This ensures that all findings are evaluated by an experienced specialist.

What happens if an aneurysm is found?

After the discovery, the next steps depend on:

• the size and location of the aneurysm
• the patient’s age
• any symptoms
• other risk factors

Most small aneurysms are monitored regularly using imaging. In some cases, treatment may be considered. Follow-up care is planned in specialized medical care.

Imaging can also reveal asymptomatic changes

MRI images may also reveal changes that do not cause symptoms, such as small vascular abnormalities or benign structural findings.
It is the radiologist’s role to assess the significance of these findings and, if necessary, recommend further investigations.