Brain aneurysm

What is a brain (cerebral) aneurysm?

A brain or cerebral aneurysm is where the wall of an artery or blood vessel in the brain is weakened, causing it to swell into a blister-like shape. As aneurysms grow, they put pressure on the surrounding tissue, which can cause a variety of symptoms.

Diagram of the brain shows a saccular aneurysm and a fusiform aneurysm (copyright shutterstock_101419798)

If detected, it is vital to seek immediate medical advice as an aneurysm could rupture at any time. This is known as a brain haemorrhage or haemorrhagic stroke.

Where the wall of an artery or blood vessel in the brain is weakened, it may swell in a blister-like shape and form what is known as a cerebral aneurysm.

What happens when an aneurysm bursts (ruptures)?

Diagram shows a haemorrhagic stroke, with blood escaping from a ruptured blood vessel (copyright shutterstock_78688366)

As aneurysms grow, symptoms can occur as they put pressure on the surrounding tissue. Sometimes, however, no symptoms will occur.

An aneurysm can rupture at any time, causing serious bleeding into the surrounding tissue and damaging the brain.

This is called a haemorrhage or haemorrhagic stroke.

How is an aneurysm treated?

Treatment for aneurysm is difficult due to problems accessing parts of the brain, but generally involves surgical clipping, where a section of skull is removed and a clip placed over the neck of the aneurysm to stop blood flowing into it, or coiling, where a series of platinum coils are threaded from the patient's lower body up into the brain aneurysm, filling it with the platinum and stopping blood flow.

Not all treatments are suitable in all cases, and the medical team will be able to advise on this.

What are the effects of a brain aneurysm?

A brain aneurysm may not cause any symptoms unless it ruptures. However in some cases it can cause symptoms such as:

  • Visual disturbances
  • Pain above or around the eye
  • Numbness or weakness in the face
  • Difficulty speaking
  • Headaches
  • Balance problems
  • Difficulty concentrating
  • Problems with short-term memory

You should always seek medical advice if you experience these symptoms. 

A ruptured aneurysm is an extremely serious condition which requires emergency medical attention. Symptoms can include:

  • A sudden, agonising headache
  • Feeling or being sick
  • Stiff neck or neck pain
  • Sensitivity to light
  • Blurred or double vision
  • Sudden confusion
  • Loss of consciousness
  • Seizures
  • Weakness on one side of the body or in any limbs

You should seek urgent medical advice if you are experiencing any of these symptoms. Dial 999 and ask for an ambulance. 

An aneurysm can cause an acquired brain injury, and you can read more about the symptoms of this in the Effects of brain injury section. 

My story

"There were no warning signs that something may be wrong,"

On 22 February 2015, 43-year-old Claire Cowlishaw sustained a devastating brain injury following two ruptured aneurysms that would leave her with severe short-term memory problems and challenge her inseparably close relationship with her 18-year-old daughter, Lauren.

Read story