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  • Brain Aneurysm

    Brain Aneurysm

    What is a Brain Aneurysm?

    A brain aneurysm, also called a cerebral aneurysm, is a weak spot along a blood vessel in the brain that bulges outward. Often described as balloon-like in appearance, these malformations may burst and bleed into the brain (hemorrhage, or hemorrhagic stroke). This can potentially cause life-threatening complications.

    Even if a brain aneurysm does not burst, it can cause other problems by putting pressure on nerves or brain tissue. Most cerebral aneurysms occur along a ring of interconnected arteries at the base of the brain known as the circle of Willis.

    Additional Information

    Types of Brain Aneurysms

    There are different types of cerebral aneurysms:

    • Saccular is the most common type. It develops along weak spots in the wall of an artery.
    • Dissecting is a type of aneurysm that forms from tears to the innermost layers of a blood vessel. It follows a traumatic injury or plaque formation.
    • Mycotic is a type of brain aneurysm that is caused by a bacterial infection in the wall of an artery.
    • Pseudoaneurysm is the dilatation of an artery that forms when the artery is injured by abrupt, severe trauma.

    How common are brain aneurysms?

    About five percent of the population has at least one cerebral aneurysm. One-third of those people have more than one. Each year, these lesions rupture in 10 to 20 per 100,000 people.

    Who gets brain aneurysms?

    Brain aneurysms can occur in anyone at any age, but they are more common in adults than in children and slightly more common in women than in men. They also occur more often in people with certain genetic diseases and blood vessel disorders.

    Other causes of aneurysms include:

    • Head trauma
    • Tumors
    • High blood pressure
    • Infection
    • Atherosclerosis and other diseases of the vascular system
    • Cigarette smoking
    • Drug abuse

    How are brain aneurysms diagnosed?

    Most cerebral aneurysms go unnoticed until they rupture or are found by imaging tests done for other reasons.

    The following tests may be used to diagnose an aneurysm:

    • Angiography
    • CT scan
    • MRI scan
    • Lumbar puncture (spinal tap)

    Symptoms of Brain Aneurysm


    Cerebral aneurysms usually do not cause symptoms until they either become very large or burst. Most are found when they rupture and bleed into the space between the skull and the brain. This is a serious condition called subarachnoid hemorrhage, or hemorrhagic stroke.

    Symptoms of a brain aneurysm pressing on nearby tissue and nerves may include:

    • Pain above and behind the eye
    • Numbness, weakness, or paralysis on one side of the face
    • Dilated pupils
    • Vision changes

    Symptoms of a ruptured aneurysm may include:

    • Sudden, severe headache
    • Double vision
    • Drooping eyelid
    • Nausea
    • Vomiting
    • Stiff neck
    • Sensitivity to light
    • Loss of consciousness, including coma
    • Seizures

    Subarachnoid hemorrhage can cause serious complications, including:

    • Hydrocephalus is an abnormal buildup of cerebrospinal fluid in the skull that puts pressure on brain tissue.
    • Vasospasm is a narrowing of blood vessels. It reduces the amount of blood flow to the brain and can cause stroke or tissue damage.

    If you are experiencing these symptoms, contact a medical professional.

    Treatments for Brain Aneurysm


    Not all aneurysms rupture. Small lesions may be watched for growth and symptom onset. When deciding whether or not to treat an unruptured brain aneurysm, your doctor will consider many factors. These include the type, size, and location of the aneurysm; your health, age, and medical history; and the risks associated with treatment.

    Treatments for brain aneurysms include:

    • Microvascular clipping is a surgical procedure that involves cutting off blood flow to the brain aneurysm. Your neurosurgeon will open up part of your skull and place a clip on the neck of the aneurysm to halt its blood supply.
    • Occlusion is a procedure where your neurosurgeon clamps off the entire artery leading to the malformation. This surgery is often performed when an aneurysm has damaged an artery. It may be accompanied by a bypass, in which a small blood vessel is surgically grafted to the artery. This reroutes blood flow away from the damaged section of the vessel.
    • Endovascular embolization is a treatment where a catheter is
      stent and coil of a giant aneurysm

      A brain aneurysm treated with stents and endovascular coils

      inserted into a major artery and threaded through the body to the site of the brain aneurysm. Coils are passed through the catheter and then released into the aneurysm. The coils then fill the aneurysm, preventing blood from flowing through it and causing it to clot. This decreases the chances of rupture.

    Request an Appointment with a Brain Aneurysm Specialist

    Call (602) 406-3181

    About Barrow Neurological Institute
    Since our doors opened as a regional specialty center in 1962, we have grown into one of the premier destinations in the world for neurology and neurosurgery. Our experienced, highly skilled, and comprehensive team of neurological specialists can provide you with a complete spectrum of care–from diagnosis through outpatient neurorehabilitation–under one roof. Barrow Neurological Institute: Discover. Educate. Heal.