A brain aneurysm, also known as a cerebral aneurysm or an intracranial aneurysm, is a balloon-like bulge of a brain artery that is caused by a weakening in the blood vessel’s wall.  As blood flows through the artery, it fills the aneurysm.

Aneurysms usually form underneath the brain or in between the brain’s lobes, in a space around the brain called the subarachnoid space.  If the aneurysm ruptures (breaks open), then blood fills the subarachnoid space, a condition known as subarachnoid hemorrhage. Subarachnoid hemorrhage can cause devastating brain damage, and it is often fatal.   

If you have been diagnosed with a brain aneurysm, also called a cerebral aneurysm or intracranial aneurysm, you should be evaluated by a neurosurgeon who specializes in this disorder.

Brain Aneurysm Symptoms

Unfortunately, most aneurysms will not cause warning symptoms before they rupture.  Sometimes a brain aneurysm is found after a patient has a symptom, such as:

  • Headaches
  • Changes in vision
  • Seizures

When a brain aneurysm ruptures, it usually causes a sudden, severe headache.  It may also cause loss of consciousness or seizures.  Patients with these symptoms should be taken to the emergency room immediately. 

Causes of Brain Aneurysms

Brain aneurysms can form in patients who are otherwise healthy, with no apparent cause. There are also some factors that increase the chance that an aneurysm will form:

  • Smoking
  • High blood pressure (hypertension)
  • Family history of brain aneurysm
  • Presence of a brain arteriovenous malformation (AVM)
  • Rare genetic conditions:
    • Polycystic Kidney Disease
    • Ehlers-Danlos Syndrome
    • Marfan Syndrome
    • Fibromuscular Dysplasia (FMD)

How is a Brain Aneurysm Diagnosed?

Ideally, an aneurysm will be discovered before it ruptures.  Unruptured aneurysms are sometimes diagnosed after patients have imaging studies of the brain for various reasons.  Aneurysms are usually not identified on routine CT scans or MRI scans, but they can be seen on specialized CT and MRI scans, called CTA and MRA.

Treatments for Brain Aneurysms

A ruptured brain aneurysm (causing subarachnoid hemorrhage) is an emergency, and requires urgent treatment.  The Neuroscience ICU at MedStar Georgetown has an effective protocol for the treatment of subarachnoid hemorrhage, and we accept emergency patient transfers from other hospitals in the Washington, DC area and beyond.

If you have an unruptured brain aneurysm, you should be carefully evaluated by a specialized cerebrovascular neurosurgeon.  In some cases, the aneurysm has no significant risk of causing problems, and you will not need to undergo a procedure for treatment.  Your neurosurgeon may order follow-up imaging studies.  In other cases, the aneurysm may be life-threatening if it is left untreated.  Your cerebrovascular neurosurgeon will evaluate several factors, often in consultation with other specialists, to determine which treatment is best for you.

The best way to treat an aneurysm depends on a number of factors, including the aneurysm’s size, shape, location, and other characteristics.  MedStar Georgetown University Hospital has neurosurgeons who have specialized training in the treatment of aneurysms.  Your doctor will counsel you on the best approach to your aneurysm, whether it is microsurgical treatment, endovascular therapy, or continued observation. 

Learn more about the advanced brain aneurysm treatments we offer at MedStar Georgetown.

Make an Appointment

For more information or to make an appointment with one of our cerebrovascular neurosurgeons, call

855-546-0592