Cerebral Aneurysms

A brain aneurysm occurs when a blood vessel in the brain bulges or balloons. The aneurysm can leak or burst, which causes bleeding in the brain, a condition known as hemorrhagic stroke . Typically, the ruptured aneurysm occurs in the area between the brain and the thin tissue that separates the brain from the skull. This type of hemorrhagic stroke is known as a subarachnoid hemorrhage.

A ruptured aneurysm is an emergency situation; call 911 immediately.

Brain aneurysms are classified as unruptured, leaking or ruptured:

  • Unruptured aneurysm — Most aneurysms do not cause symptoms. When an aneurysm does cause symptoms, it can produce pain above and behind an eye; a dilated pupil in a single eye; double vision or a change in vision; a drooping eyelid; or numbness, weakness or paralysis in one side of the face. 
  • Leaking aneurysm — Also known as a sentinel bleed, a leaking aneurysm may only produce mild symptoms. A ruptured aneurysm is almost always preceded by a sentinel bleed, so a persistent headache can be a warning, especially in people with a previous diagnosis of a brain aneurysm. 
  • Ruptured aneurysm — Symptoms of a ruptured brain aneurysm often appear suddenly. A sudden severe headache, often described as “the worst headache of my life,” is the key symptom. Other symptoms can include the following: 
    • Nausea and vomiting
    • Stiff neck
    • Blurred or double vision
    • Light sensitivity
    • Drooping eyelid
    • Confusion
    • Seizure
    • Loss of consciousness

According to the American Stroke Association , most aneurysms develop after the age of 40, and they usually form in arterial branches, where the pressure is turbulent. Amphetamine or cocaine use or infection can result in the development of brain aneurysms. In addition, smoking and high blood pressure increase the risk of aneurysms.

Most brain aneurysms, often detected during tests for other conditions, do not rupture or create health problems or symptoms.

If You Think Someone Is Having a Stroke
When it comes to stroke, the best way to determine if someone is having one is to think FAST.

  • Face — Does the face look uneven? Ask the person to smile. 
  • Arms — Does one arm drift down? Ask the person to raise both arms. 
  • Speech — Does their speech sound strange? Ask the person to repeat a simple phrase. 
  • Time — If you observe any of these signs, it is time to call 911. 

These symptoms may indicate that a stroke or has occurred — immediate medical attention is required.

Diagnosing Brain Aneurysms
Our team at Houston Methodist performs a variety of tests to determine if a patient with a sudden severe headache or other symptoms may have an unruptured, leaking, or ruptured aneurysm. These tests can include brain imaging, including computed tomography (CT), magnetic resonance imaging (MRI) or cerebral angiogram, or a cerebrospinal fluid test (spinal tap) to look for red blood cells in the fluid surrounding the brain and spinal cord.

Screening for Brain Aneurysms
Screening for unruptured aneurysms is not generally recommended; however, some people may choose to undergo imaging studies for screening if they have a parent or sibling who has had a ruptured aneurysm or if they have a congenital condition that increases the risk of aneurysms.

Treating Brain Aneurysms
The two commonly performed treatments for ruptured brain aneurysms include the following:

  • Surgical clipping — A clip is placed on the aneurysm to stop the blood flow to it; this can prevent a second round of bleeding. 
  • Endovascular coiling (or endovascular embolization) — A less invasive procedure than surgical clipping, tiny platinum coils are placed into the aneurysm, which blocks the blood flow, causing the blood to clot. 

Both of these procedures carry some risk, usually additional bleeding or a loss of blood flow. A newer method involves the placement of a blood flow diverter, which is used in larger aneurysms that are not amenable to the above treatments.

Other methods used to treat symptoms and manage or prevent complications of ruptured aneurysms include the following:

  • Pain relievers to manage pain 
  • Calcium channel blockers to prevent spasms of the blood vessels, a common complication of ruptured aneurysms 
  • Treatments to maintain or improve blood flow 
  • Angioplasty to dilate narrowed blood vessels 
  • Anti-seizure medication 
  • Placement of draining catheters or shunts to relieve pressure 
  • Rehabilitative therapy to help with regaining abilities, such as speech or walking, lost due to a ruptured aneurysm 

Surgical clipping and endovascular coiling are also used to treat unruptured brain aneurysms; however, in some cases, the risks may outweigh the benefits. Factors that may affect your decision to treat an unruptured aneurysm include the size and location of the aneurysm; your age and general health, along with lifestyle habits such as smoking and conditions such as high blood pressure; a family history of ruptured aneurysms; and the presence of a congenital condition that increases the risk of a ruptured aneurysm.


Our physicians at Houston Methodist specialize in treating brain aneurysms at the following convenient locations.