A cerebral aneurysm is a weak or thin spot on a blood vessel in the brain that balloons out and fills with blood. Also known as a brain or inter-cranial aneurysm, a cerebral aneurysm can press on a nerve or surrounding tissue and can leak or burst, causing bleeding into the brain (hemorrhagic stroke). A normal artery wall is made up of three layers. In an aneurysm the wall is weakened due to the loss of a muscular layer. Aneurysms can develop in arteries anywhere in the brain.
Wellstar neurologists and neurosurgeons are expert in identifying and treating brain aneurysms.
There are three types of cerebral aneurysms:
- A saccular ("berry") aneurysm looks like a berry with a narrow stem. More than one aneurysm may be present. More than 90 percent of aneurysms are this type.
- A fusiform aneurysm bulges out on all sides.
- A dissecting aneurysm is the result of a tear along the length of the artery in the inner layer of the artery wall. Leakage of blood between the layers of the wall may cause ballooning or it may block blood flow through the artery. This type of aneurysm is usually the result of a traumatic injury.
Three to five million people in the United States have cerebral aneurysms, but most produce no symptoms. Aneurysms typically develop after age 40, enlarging slowly and becoming weaker as they grow, much as a balloon stretches over time.
Experts have not determined the reasons for weakening in the walls of an artery. Generally, cerebral aneurysms are associated with certain locations in the brain where pressure is higher and with factors linking high blood pressure and smoking.
A ruptured aneurysm can quickly become life threatening and requires immediate medical treatment.
Most aneurysms do not rupture, but still cause symptoms and health problems. In some cases an un-ruptured aneurysm may bleed, depending on the size, shape and location. Brain damage can result.
Aneurysms sometimes run in families, but people are not usually born with a predisposition to them. Some aneurysms are the result of infections, use of drugs like amphetamines and cocaine that damage the blood vessels of the brain, or accident-related brain trauma.
When an aneurysm ruptures (subarachnoid hemorrhage) people complain of an intense ("worst of my life") headache. Symptoms can also include:
- Nausea and vomiting
- Stiff neck or neck pain
- Blurred or double vision
- Pain above and behind the eye
- Dilated pupils
- Sensitivity to light
- Loss of sensation
- Loss of consciousness
- Loss of balance or coordination
- Back or leg pain
- Problems with the eyes, nose, tongue and/or ears that are controlled by one or more cranial nerves
Symptoms of an unruptured cerebral aneurysm can include:
- Headache (though not common)
- Eye pain
- Problems with eye movement or sight
- Drooping eyelid
- Numbness, weakness or paralysis on one side of the face
- Problems with speech or perception
- Memory difficulty
- Decrease in concentration
If you or someone you are with experiences a sudden, severe headache, loses consciousness or has a seizure, emergency medical assistance is required.
The formation of aneurysms in the brain is associated with a variety of inherited risk factors including (but not limited to):
- Congenital abnormality in artery wall
- Family history of brain aneurysms
- Being over age 40
- Being a woman
- Reduced (post-menopause) estrogen level
- Heavy consumption of alcohol
- A variety of disorders present from birth including Ehlers-Danlos Syndrome, Polycystic Kidney Disease, Marfan Syndrome and Fibromuscular Dysplasia (FMD)
- Presence of an arteriovenous malformation (AVM)
- Drug use, particularly cocaine
- Traumatic head injury
There are no known ways to prevent a cerebral aneurysm from forming. People with a diagnosed brain aneurysm should carefully control high blood pressure, stop smoking and avoid cocaine use or other stimulant drugs. Talk with your Wellstar neurosurgeon or neurologist about the risks and benefits of taking aspirin or other drugs that thin the blood, and about the risks of taking oral contraceptives.
Other steps you can take to reduce the chance of a brain aneurysm:
- Do not smoke or use recreational drugs. Wellstar has a variety of programs and options to help people stop smoking and address drug use and addiction.
- Eat a healthy diet and get regular exercise in order to keep blood pressure under control.
- Limit caffeine, as it is a stimulant that can cause a sudden rise in blood pressure.
- Avoid straining, especially sudden, forceful sustained exertion.
Most brain aneurysms are identified because they have ruptured or are discovered during a diagnostic exam for another purpose. That's why it's important to visit your Wellstar neurosurgeon or neurologist if you believe you or a loved one may be experiencing symptoms associated with an aneurysm. An increasing number of aneurysms are being found before they rupture as a result of reports of symptoms followed by noninvasive tests that indicate the status of blood vessels in the head.
Your neurologist will conduct an examination and ask you questions about symptoms including headache, neck pain, nausea and vomiting or other neurological symptoms.
Screening (testing for the possibility of a condition) for brain aneurysm is not common. But you may want to talk with your doctor about the possible benefit of a screening test (1) if you have a congenital birth condition that increases your chance of an aneurysm, or (2) if close family members have had ruptured brain aneurysms.
Tools and Tests
Wellstar physicians use a wide spectrum of tools and tests to confirm the diagnosis of an aneurysm. Your doctor will determine which tests to use according to specific symptoms and other considerations.
- Cerebral angiography is a dye test used to analyze arteries or veins in the brain. Angiogram can reveal the degree of narrowing or obstruction of an artery or blood vessel as well as weak spots like aneurysms. The test is typically performed in a Wellstar Vascular Institute. It involves insertion of a flexible catheter into an artery. Contrast dye is released into the bloodstream and sent to the head and neck, and then X-rays are taken.
- Computed tomography angiogram (CTA) is a non-invasive test that uses X-rays and computer technology to detect the presence of a cerebral aneurysm. Computed tomography (CT) for aneurysms that have burst, CT can detect if blood has leaked into the brain.
- Magnetic resonance imaging (MRI) uses a combination of magnets and computer technology to produce detailed images of brain tissue.
- Magnetic resonance angiography (MRA) This noninvasive procedure uses a combination of magnetic resonance technology and intravenous contrast dye to visualize blood vessels.
Wellstar neurologists and neurosurgeons offer the following treatment options for a cerebral aneurysm that has not burst.
Observation/Medication: If the aneurysm is very small or in a location your doctor considers low-risk, the doctor may recommend repeated testing over time and cautious observation of the status of the aneurysm. For some patients with unruptured aneurysms, including those with high blood pressure and risk factors for surgery, the doctor may recommend medication that lowers blood pressure and steps like quitting smoking and paying careful attention to diet and exercise.
Open craniotomy (surgical clipping): This procedure is used to close off an aneurysm. It involves the surgical removal of part of the skull. The surgeon exposes the aneurysm and places a metal clip across the neck of the aneurysm to prevent blood flow. A similar procedure involves clamping off (occluding) the entire artery that leads to the aneurysm. This is an option when the aneurysm has damaged the artery.
Endovascular coiling (coil embolization): This is a minimally invasive alternative to surgery. A hollow plastic tube (catheter) is inserted into a blood vessel in the groin, and then moved up into the blood vessels in the brain. Once the catheter is placed, very tiny, soft platinum coils are advanced through the catheter into the aneurysm. These coils conform to the shape of the aneurysm and eventually serve to clot off the aneurysm, preventing it from rupturing.
Other treatments: Other treatment for ruptured brain aneurysms help control symptoms and manage complications. These may include pain relievers, anti-seizure medications, catheters and shunts to relieve pressure on the brain from excess cerebrospinal fluid, as well as rehabilitative therapy. Wellstar offers compassionate, effective therapy delivered by experienced therapists at convenient locations.
Your physician will discuss the risks and benefits of the various options with you and will make a recommendation based on your aneurysm, your age, general health, ability to undergo surgery, family history and any conditions that might increase the risk of a rupture.
Ongoing Care for Aneurysms
Individuals who receive treatment for an unruptured aneurysm can expect to undergo some level of rehabilitation. Although there is a chance that an aneurysm will recur, many patients go on to lead productive lives without recurrence. Ongoing care involves attention to blood pressure, diet, exercise and avoiding activities that may put them at further risk.
An aneurysm that bursts can be fatal or can lead to hemorrhagic stroke. The prognosis depends on many factors including the age and general health of the patient, location of the aneurysm, pre-existing conditions and time between the rupture and receiving medical attention. That's why Wellstar neurologists and neurosurgeons emphasize the critical importance of early diagnosis and treatment.
Not smoking is an important step to help avoid a brain aneurysm. Wellstar offers smoking cessation, a series of classes that deal with the preparation to quit smoking so that individuals learn approaches that work best for them.