The neurologists and neurosurgeons at Torrance Memorial Medical Center offer expert care for all types of aneurysms. Our affiliation with the neurology team at Cedars-Sinai — which is ranked among the best hospitals in the nation for neurology care by U.S. News & World Report — means that our patients have access to the most advanced treatment options.

What is a brain aneurysm?

An aneurysm occurs when the walls of a blood vessel become weakened and expand outward to create a balloon-like pouch. Aneurysms can happen to any blood vessel in your body. When they occur in your brain, they are called cerebral or brain aneurysms.

Brain aneurysms that do not rupture are generally harmless and usually do not cause symptoms. However, a burst or ruptured aneurysm is a life-threatening medical emergency and requires immediate medical attention. A ruptured brain aneurysm may cause stroke, coma, brain damage, and even death.

The first sign of a ruptured brain aneurysm is usually a sudden, severe headache often accompanied by seizures, loss of consciousness, vomiting, and dizziness. Any combination of these symptoms requires immediate medical attention.

Types of Brain Aneurysms

Brain aneurysms are categorized into a few different groups depending on their size and type.

Brain aneurysms by size include:

  • Small: less than 11 millimeters in diameter or about the size of a small pencil eraser
  • Medium: 11 to 25 millimeters in diameter or about the size of a dime
  • Giant: greater than 25 millimeters in diameter or anything larger than a dime

Brain aneurysms by type include:

  • Saccular aneurysm. The most common type of brain aneurysm, saccular aneurysms are also commonly referred to as berry aneurysms because of their shape, which resembles a berry hanging on a stem. Most saccular aneurysms occur in adults in the arteries at the base of the brain.

  • Fusiform aneurysm. Fusiform aneurysms cause your artery to expand on all sides. Although they are less likely to rupture than saccular aneurysms, they can still cause brain damage or stroke.

  • Mycotic aneurysm. Mycotic aneurysms happen after an infection weakens the wall of your blood vessel and causes it to bulge out.

Brain aneurysms sometimes leak small amounts of blood before they rupture. This type of bleeding is called a sentinel bleed and can cause sentinel or “warning” headaches.

Symptoms

Although most small unruptured brain aneurysms cause no symptoms, symptoms of larger unruptured brain aneurysms can include:

  • Dilated pupils
  • Pain above and behind one eye
  • Numbness or weakness
  • One-sided facial paralysis
  • Vision problems

Ruptured brain aneurysms can cause extreme symptoms that include:

  • Sudden-onset and extremely painful headache
  • Seizure
  • Cardiac arrest or heart attack
  • Loss of consciousness
  • Nausea or vomiting
  • Vision problems such as seeing double, light sensitivity, or blurry vision
  • Confusion
  • Drooping eyelid
  • Stiff neck

Causes and Risk Factors

Some people are born with brain aneurysms while others develop them later in life. Although there are no known causes for brain aneurysms, there are several risk factors that increase your chances of developing a brain aneurysm, including:

  • Being age 40 or older
  • Smoking
  • Atherosclerosis, or hardened arteries
  • Abusing drugs, particularly cocaine or amphetamines
  • Heavy consumption of alcohol
  • Untreated high blood pressure
  • Head trauma
  • Brain tumor
  • Infection of the arterial wall
  • Deformities in or tangles of your blood vessels

Other risk factors that may increase the chance of a brain aneurysm bursting or rupturing include:

  • Personal or family history of brain aneurysms, especially ruptured aneurysms
  • Smoking
  • High blood pressure
  • Large or growing aneurysms

Diagnosis

Most brain aneurysms will only be diagnosed after they rupture. Tests to determine if you have a ruptured brain aneurysm include:

  • Computed tomography (CT) scan. A CT scan is used to determine if there is bleeding in your brain and is usually the first test ordered when a ruptured brain aneurysm is suspected.

  • Magnetic resonance imaging (MRI). An MRI uses radio waves and magnetic fields to create detailed images of your body. Magnetic resonance angiography (MRA) examines your brain and can show the size, shape, and location of your arteries and brain aneurysms.

  • Cerebrospinal fluid analysis. This procedure examines the fluid in your spine to check for the presence of red blood cells, which would indicate bleeding around your brain.

  • Cerebral angiography. During cerebral angiography, a long, flexible tube called a catheter will be inserted into an artery in your arm or leg and guided to your brain and neck arteries, where a small amount of dye will be injected. X-rays of your head and neck will be taken to determine if you have any cerebral aneurysms.

If you have a family history of brain aneurysms or have a condition that increases your risk of a brain aneurysm, your doctor may recommend screening for unruptured aneurysms.

Treatment

Treatment options for brain aneurysms depend on many factors, including whether or not your aneurysm is ruptured or expected to rupture, your age, health, medical history, symptoms, and personal preference.

Surgery may be appropriate for you if you have a ruptured brain aneurysm or a brain aneurysm that is at high risk of rupturing. When considering surgery, your doctor will review your general health, medical history, and the risk your brain aneurysm poses versus the risk of surgery.

Surgical procedures for brain aneurysms include:

  • Surgical clipping. During this procedure, your surgeon will remove a portion of your skull to access your aneurysm and the arteries that flow into it. Your surgeon will place a small metal clip on the base of your aneurysm, stopping the blood flow.

  • Endovascular coiling. During endovascular coiling, a catheter is threaded into your arteries through a small incision in your groin. Using the catheter, your surgeon will insert a soft platinum wire coil into your aneurysm to seal your aneurysm off from your artery.

  • Flow diversion. During flow diversion, a catheter is threaded into your arteries through a small incision in your groin. Using the catheter, your doctor will place a small stent, or a flexible mesh tube, near your aneurysm to prevent blood from entering it.

  • Cerebrospinal fluid drainage surgery. This procedure is used to reduce the harmful pressure on your brain from the excess cerebrospinal fluid associated with a ruptured brain aneurysm.

Other treatment options include:

  • Blood pressure medication. Blood pressure medication is used to control high blood pressure and lower the risk of your aneurysm rupturing.

  • Anti-seizure medication. Anti-seizure medication is used to control seizures that may result from a ruptured brain aneurysm.

  • Calcium channel blockers. Calcium channel blockers are used to lower your risk of stroke resulting from a ruptured brain aneurysm.

  • Pain relievers. Pain relievers are used to treat headaches that can accompany a brain aneurysm.

  • Rehabilitative therapy. Speech, physical, or occupational therapy may be recommended if a brain aneurysm leads to brain damage and you need to relearn skills.

  • Lifestyle changes. Lifestyle changes can help reduce the risk of your brain aneurysm rupturing. Recommended lifestyle changes include quitting smoking and using recreational drugs, as well as exercising and eating a healthy diet.