Brain Aneurysm (Cerebral Aneurysm)
A brain aneurysm (also called a cerebral or intracranial aneurysm) is a weak area in the wall of a blood vessel in the brain that bulges outward, like a small balloon.
What is a Brain Aneurysm?
A brain aneurysm (also called a cerebral or intracranial aneurysm) is a weak area in the wall of a blood vessel in the brain that bulges outward, like a small balloon. These often form where blood vessels branch, especially at the major arteries at the base of the brain in an area called the Circle of Willis. Aneurysms can vary in size from a few millimetres to many centimetres.
Most brain aneurysms do not cause symptoms and are found by chance during brain scans done for other reasons. In many cases, they remain stable and never rupture.
However, if an aneurysm bursts (ruptures), it causes bleeding around the brain, known as a subarachnoid hemorrhage (SAH). This is a medical emergency that requires immediate treatment. A ruptured aneurysm can be life-threatening and may lead to serious complications, including long-term brain injury or death.
At One Brain and Spine, our cerebrovascular neurosurgeons are highly experienced in treating both unruptured and ruptured brain aneurysms. We work within a multidisciplinary team, including neurointerventionalists, to provide a full range of treatment options. These include microsurgical clipping and minimally invasive endovascular procedures, such as coiling, so care can be tailored to each patient.
What Causes Brain Aneurysms?
Brain aneurysms develop due to a combination of underlying vessel wall weakness and lifestyle or medical risk factors. These include:
- High blood pressure (hypertension) - is the most important modifiable risk factor. Over time, increased pressure can weaken artery walls.
- Smoking – this significantly increases the risk of both aneurysm formation and rupture.
- Family history of brain aneurysms - people with a first-degree relative (parent, sibling, or child) with a brain aneurysm have a higher risk, especially if more than one family member is affected.
- Genetic connective tissue conditions – such as polycystic kidney disease (ADPKD), Ehlers-Danlos syndrome and Marfan syndrome.
- History of a previous aneurysm - which increases the chance of developing additional aneurysms.
Factors that increase the risk of an aneurysm rupturing include larger size, location in the posterior (back) circulation of the brain, irregular shape, prior subarachnoid haemorrhage, smoking, and high blood pressure.
Symptoms of a Brain Aneurysm
Unruptured Aneurysm
Most unruptured brain aneurysms do not cause any symptoms and are often found by chance during scans done for other reasons. When symptoms do occur, they are usually caused by the aneurysm pressing on nearby nerves or areas of the brain. Although this is uncommon, some people may notice symptoms such as a persistent or severe headache, blurred or double vision, a drooping eyelid, numbness or weakness. These symptoms are not specific to brain aneurysms and can be caused by other conditions. However, if you develop new, unusual, or worsening symptoms, it is important to seek medical attention.
Ruptured Aneurysm — Subarachnoid Haemorrhage
A ruptured brain aneurysm is a life-threatening emergency. The most common symptom is a sudden, severe headache that reaches maximum intensity within seconds. This is often described as the worst headache of a person’s life or a “thunderclap” headache. Other symptoms may include neck stiffness, nausea and vomiting, sensitivity to light, or loss of consciousness. Call 000 and seek medical assistance immediately.
How is a Brain Aneurysm Diagnosed?
Doctors use several imaging tests to diagnose brain aneurysms and assess the risk of bleeding:
- CT angiography (CTA) — a commonly used scan that is quick, widely available, and very good at detecting most aneurysms, including small ones. It involves an injection of contrast dye into a vein.
- MR angiography (MRA) — a non-invasive scan often used to monitor aneurysms over time or to screen people at higher risk.
- Cerebral angiography (also called digital subtraction angiography or DSA) — a more detailed test performed by guiding a thin tube (catheter) through the blood vessels. It provides the most precise information and is often used when planning treatment.
- Non-contrast CT scan — usually the first test if a ruptured aneurysm is suspected, as it can quickly detect bleeding around the brain. However, it does not show blood vessels or identify aneurysms directly.
- Lumbar puncture — may be needed in some cases if a ruptured aneurysm is suspected but not confirmed on a CT scan.
Treatment of Brain Aneurysms
Treatment decisions are based on balancing the risk of the aneurysm rupturing against the risks of treatment. Care is individualised for each patient, considering both patient and aneurysm factors. A ruptured aneurysm requires urgent treatment, while unruptured aneurysms may be monitored or treated depending on these factors.
Observation
Small, unruptured aneurysms may be monitored with regular scans, particularly in older patients or those with other medical conditions. Managing risk factors such as high blood pressure and smoking is an important part of care. Regular follow-up with MRA or CTA is typically required.
Microsurgical Clipping
A craniotomy is an operation in which a surgeon makes an opening in the skull to reach the aneurysm directly and places a small clip across its base. This is performed using specialised surgical microscopes and intraoperative angiography techniques to maximise the safety of the procedure. The clip prevents blood from entering the aneurysm while preserving normal blood flow in the artery. Clipping is an effective and durable treatment and is often recommended for certain types of aneurysms.
Endovascular Coiling
This is a minimally invasive approach performed through a catheter inserted into a blood vessel, usually in the groin or wrist. Tiny coils or other devices are placed inside the aneurysm to block blood flow and reduce the risk of rupture. Newer devices, such as flow diverters, can redirect blood away from the aneurysm. These treatments often have shorter recovery times than open surgery.
Management of Subarachnoid Haemorrhage
A ruptured aneurysm requires emergency treatment in a specialised hospital. Care involves a team of specialists, including neurosurgeons, neurointerventionalists, and intensive care doctors. Treatment focuses not only on securing the aneurysm but also on managing complications such as blood vessel narrowing (vasospasm), fluid buildup in the brain (hydrocephalus), and other medical issues.
Frequently Asked Questions — Brain Aneurysm Melbourne
How common are brain aneurysms?
Brain aneurysms are relatively common and are found in about 2–5% of people on brain scans. Most do not cause any symptoms and never rupture. For small aneurysms, the risk of rupture is generally low, often less than 1% per year. However, the risk can be higher depending on factors such as the size and shape of the aneurysm and a person’s individual risk factors.
Should I be screened for a brain aneurysm if a family member has one?
Screening may be recommended if two or more first-degree relatives (parent, sibling, or child) have had a brain aneurysm or subarachnoid haemorrhage. It is usually performed with an MRA scan, which is non-invasive, and may be repeated every five years. People with certain inherited conditions, such as polycystic kidney disease, may also be advised to have screening, sometimes more frequently. It is important to discuss your individual risk with your GP or a neurosurgeon.
Is clipping or coiling better for a brain aneurysm?
Both treatments are effective. The best option depends on the aneurysm’s size, shape, and location, as well as your overall health. Endovascular treatments (such as coiling) are often preferred for aneurysms in certain locations or in patients where a less invasive approach is suitable. Surgical clipping may be recommended for other aneurysms, particularly those with more complex anatomy. One Brain and Spine's multidisciplinary team will recommend the most appropriate treatment for your individual situation.
What is a thunderclap headache?
A thunderclap headache is a sudden, severe headache that reaches maximum intensity within seconds. It is often described as the worst headache a person has ever experienced. This can be a sign of a serious condition such as a ruptured brain aneurysm and requires immediate medical attention. Call 000 or go to the nearest emergency department straight away.
Why Choose One Brain and Spine for Brain Aneurysm in Melbourne?
One Brain and Spine is a specialist neurosurgical group practice in Melbourne, bringing together extensive expertise in brain, spinal, and peripheral nerve surgery. Our team has particular strength in cerebrovascular neurosurgery, delivering multidisciplinary care using the latest technology available in Australia. We are committed to providing comprehensive, patient-focused treatment through:
- Specialist cerebrovascular neurosurgeons — internationally fellowship-trained with subspecialty cranial and cerebrovascular surgery expertise
- Advanced technology — including intraoperative navigation, neuromonitoring, and state-of-the-art microsurgical techniques
- Multidisciplinary care — close collaboration with neurologists, neurointerventionalists, and radiation oncologists to ensure optimal outcomes
- Patient-centred approach — compassionate care with clear explanations of your diagnosis and all available treatment options
- All major health funds accepted