Brain aneurysm

Symptoms

Symptoms of an unruptured brain aneurysm

A brain aneurysm rarely causes any symptoms unless it bursts (ruptures).

Unruptured brain aneurysms occasionally cause symptoms if they're particularly large or press against tissues or nerves inside the brain.

Symptoms of an unruptured brain aneurysm can include:

• visual disturbances, such as loss of vision or double vision
• pain above or around your eye
• numbness or weakness on 1 side of your face
• difficulty speaking
• headaches
• loss of balance
• difficulty concentrating or problems with short-term memory

Ruptured brain aneurysm

Symptoms of a ruptured brain aneurysm usually begin with a sudden agonising headache.

It's been likened to being hit on the head, resulting in a blinding pain unlike anything experienced before.

Other symptoms of a ruptured brain aneurysm also tend to come on suddenly and may include:

• feeling or being sick
• a stiff neck or neck pain
• sensitivity to light
• blurred or double vision
• sudden confusion
• loss of consciousness
• fits (seizures)
• weakness on 1 side of the body or in any limbs

Causes

Exactly what causes the wall of affected blood vessels to weaken is still unclear, although risk factors have been identified.

These include: 

• smoking
• high blood pressure
• a family history of brain aneurysms

In some cases, an aneurysm may develop because there was a weakness in the walls of the blood vessels at birth.

Diagnosis

A brain aneurysm is usually diagnosed using angiography. Angiography is a type of X-ray used to check blood vessels.

This involves inserting a needle, usually in the groin, through which a narrow tube called a catheter can be guided into one of your blood vessels.

Local anaesthetic is used where the needle is inserted, so you won't feel any pain.

Using a series of X-rays displayed on a monitor, the catheter is guided into the blood vessels in the neck that supply the brain with blood.

Once in place, special dye is injected into the arteries of the brain through the catheter.

This dye casts a shadow on an X-ray, so the outline of the blood vessels can be seen and an aneurysm can be recognised if one is present.

Occasionally, angiography may be done using scans instead of X-rays. These scans are called magnetic resonance angiography or CT angiography.

Magnetic resonance angiography (an MRI scan) is usually used to look for aneurysms in the brain that haven't ruptured. This type of scan uses strong magnetic fields and radio waves to produce detailed images of your brain.

CT angiography is usually preferred if it's thought the aneurysm has ruptured and there's bleeding on the brain (subarachnoid haemorrhage).

This type of scan takes a series of X-rays, which are then assembled by a computer into a detailed 3D image.

In some cases, a ruptured aneurysm is not picked up by a CT scan. If a CT scan is negative but your symptoms strongly suggest you have a ruptured aneurysm, a test called a lumbar puncture will usually be carried out.

A lumbar puncture is a procedure where a needle is inserted into the lower part of the spine to remove a sample of the fluid (cerebrospinal fluid) that surrounds and supports the brain and spinal cord. This fluid can be analysed for signs of bleeding.

Treatment Options

If a brain aneurysm is detected before it ruptures, treatment may be recommended to prevent it rupturing in future.

Most aneurysms do not rupture, so treatment is only carried out if the risk of a rupture is particularly high.

Factors that affect whether treatment is recommended include your age, the size and position of the aneurysm, your family medical history, and any other health conditions you have.

If treatment is recommended, this usually involves either filling the aneurysm with tiny metal coils (coiling) or an open operation to seal it shut with a tiny metal clip (surgical clipping).

The same techniques used to prevent ruptures are also used to treat brain aneurysms that have already ruptured.

If your risk of a rupture is low, you'll have regular check-ups to monitor your aneurysm.

You may also be given medicine to reduce your blood pressure and advice about ways you can reduce your chances of a rupture, such as stopping smoking if you smoke.

Prevention Tips

You can't always prevent brain aneurysms, but you can lower your risk by not smoking and by reducing high blood pressure.

Smoking

If you smoke, stopping can significantly reduce your risk of developing a brain aneurysm.

If you're committed to giving up smoking and your GP should be able to prescribe medical treatment to help with any withdrawal symptoms you may have after quitting.

High blood pressure

Having high blood pressure can also significantly increase your chance of developing a brain aneurysm.

You can help reduce high blood pressure by:

• eating a healthy diet – in particular, cutting down on salt and eating plenty of fruit and vegetables
• moderating your alcohol intake – men and women are advised not to regularly drink more than 14 units a week
• maintaining a healthy weight – even losing just a few pounds will make a big difference to your blood pressure and overall health
• exercising regularly – being active and taking regular exercise lowers blood pressure by keeping your heart and blood vessels in good condition
• cutting down on caffeine – it's fine to drink tea, coffee and other caffeine-rich drinks as part of a balanced diet, but it's important these drinks aren't your only source of fluid

When To See A Doctor

You should see a GP as soon as possible if you experience symptoms of an unruptured brain aneurysm.

Although most aneurysms will not rupture, it's important to get it checked in case treatment is necessary.

Medical emergency:

A ruptured brain aneurysm is a medical emergency. Call emergency immediately and ask for an ambulance if someone's experiencing symptoms of a ruptured brain aneurysm.