The neurologists and neurosurgeons at Torrance Memorial Medical Center
offer expert care for all types of brain aneurysms. Our affiliation with
the neurology and neurosurgery team at Cedars-Sinai — which is ranked
among the best hospitals in the nation for neurology and neurosurgery care by
U.S. News & World Report — means that our patients have access to some of the nation’s
top doctors, the most promising clinical trials, and the latest and best
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
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.
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
- Cardiac arrest or heart attack
- Loss of consciousness
- Nausea or vomiting
- Vision problems such as seeing double, light sensitivity, or blurry vision
- 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
- Being age 40 or older
- 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
- High blood pressure
- Large or growing aneurysms
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
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
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 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
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.