Brain aneurysm

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What is a brain aneurysm?

A brain aneurysm, also known as a cerebral aneurysm, is a type of cerebrovascular disease caused by an area of weakness on a blood vessel. It occurs when the wall of a blood vessel in your brain becomes weak and bulges. The pressure inside the blood vessel causes that weak area to balloon out. If the weakened area ruptures, it can cause a hemorrhagic stroke that can lead to brain damage or even death. Most aneurysms happen in arteries, the blood vessels that carry blood to your tissues.

Types of brain aneurysms include: 

  • Berry or saccular: This is most common type. It looks like a rounded sac off the side of the artery. 
  • Fusiform: This type of aneurysm bulges out on all sides of the artery. 
  • Mycotic aneurysm: This is a rare type of saccular aneurysm caused by an infection in the artery wall. 

Brain aneurysms are relatively common, affecting about three percent of people. About one in 1,000 people with a cerebral aneurysm experiences a hemorrhagic stroke. If hemorrhagic stroke occurs, the risk of death is about 40 percent.

Penn Medicine’s specialists in neurology and cerebrovascular surgery have deep experience in the diagnosis and treatment of brain aneurysms. We provide individualized care and advanced procedures to treat aneurysms and reduce your risk of stroke.

Recognizing the signs of a brain aneurysm

Symptoms vary depending on the condition of the aneurysm (unruptured, ruptured or leaking). A ruptured aneurysm is a medical emergency. Call 911 immediately.

What causes brain aneurysms?

Brain aneurysm causes typically involve any disease or condition that weakens or damages the wall of a blood vessel in the brain.

Some people are born with diseases associated with brain aneurysms, such as:

Other factors that increase your risk brain aneurysm include: 

  • Atherosclerosis
  • Alcohol abuse
  • Brain tumor
  • Cigarette smoking
  • Cocaine or amphetamine use
  • Family history of aneurysms
  • Head trauma
  • High blood pressure
  • Infection in the artery wall (mycotic aneurysm)
  • Intravenous drug use
  • Over 40 years of age

Brain aneurysm diagnosis

Most people don’t know they have a cerebral aneurysm until it ruptures. Doctors often find brain aneurysms during imaging tests they order for another reason.

If you have symptoms, a family history or other risk factors, your doctor may recommend brain aneurysm screening. Tests doctors use to diagnose brain aneurysms include: 

Cerebral angiography
Cerebral angiography is a procedure that uses a special dye (contrast material) and x-rays to see how blood flows through the brain.
CT angiography (CTA)
A CTA combines a CT scan with an injected contrast dye to create detailed images of blood vessels.

Brain aneurysm treatments from top neurosurgeons

Treatment for a cerebral aneurysm depends on the size and location of the aneurysm and whether it has ruptured. Your age, overall health, and medical history may also affect the treatment you receive.

For small, unruptured aneurysms, your cerebrovascular expert may recommend a “watch and wait” approach. You’ll need routine check-ups to monitor the growth of the aneurysm and any underlying health conditions. You should also stop smoking and control your blood pressure to reduce the risk of a rupture.

Larger unruptured or ruptured brain aneurysms usually require treatment. Your treatment may include a minimally invasive or surgical procedure. At Penn Medicine, our neurosurgeons perform thousands of procedures a year, bringing the most advanced treatments to your care.

Aneurysm clipping
Aneurysm clipping is a procedure in which a surgical clip is used to close off an aneurysm.
Endovascular embolization
Glue, particles or another substance is placed in an artery to block blood flow to abnormal blood vessels.

Neurorehabilitation

If you suffer a hemorrhagic stroke, you may need therapy to regain lost function. Penn Medicine offers comprehensive neurorehabilitation services to assist with recovery after a stroke. The goals of neurorehabilitation are to: 

  • Improve speech, mobility and strength 
  • Increase the skills you need to participate in daily activities 

Related specialties

Cerebrovascular disease care
We provide unmatched expertise, delivering exceptional and dedicated cerebrovascular disease care.
Neurosurgery
Our neurosurgeons are leaders in developing and bringing the latest treatment options to every patient.

Patient stories

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Kim Bello was blindsided by a ruptured brain aneurysm. Thanks to timely treatment, she made a quick and complete recovery. 

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Find a doctorCall 800-789-7366