A brain aneurysm is a ballooning-out of the wall of an artery or vein in the brain. Often this wall is weakened by disease, injury or an abnormality present at birth. They are not always life threatening, but serious consequences -- such as a stroke -- can result.
Cause
Diagnosis
Treatment
Other Resources
Causes of Aneurysms
There are multiple causes for the formation of aneurysms. The most common reason is genetic; the vessel wall has a defect in it from birth. Other causes are atherosclerosis, hypertension, infection or trauma (1).
There are two types of Aneurysms. The most common type is the Saccular, known as a "berry" aneurysm because of its shape, it has a neck and stem. The second type is a less common type of aneurysm known as the Fusiform. This is an outpouching of an arterial wall on both sides of the artery and does not have a stem.
People with unruptured brain aneurysms may have no symptoms, while others may experience the following:
- Cranial Nerve Palsy
- Dilated Pupils
- Double Vision
- Pain Above and Behind Eye
- Localized Headache
People who suffer a ruptured brain aneurysm (subarachnoid hemorrhage) will often have warning signs, including:
- Localized Headache
- Nausea & Vomiting
- Stiff Neck
- Blurred or Double Vision
- Sensitivity to Light
- Loss of Sensation
Diagnosis of Aneurysms
Aneurysms are detected by magnetic resonance imaging (MRI), computed axial tomography (CAT scans) and angiograms. They may be found incidentally, during a check-up for another reason, usually when a MRI of the brain is done, or if a patient is having severe headaches or other related symptoms.
Another detection is when the aneurysm ruptures, causing a type of stroke, known as either an intracerebral hemorrhage or a subarachnoid hemorrhage. As the vessel wall with the weakness continues to expand, the wall becomes thinner, until it eventually ruptures. The bleeding from the ruptured vessel can be either into the brain tissue itself, called an intracerebral hemorrhage, or can be in the space surrounding the brain, called a subarachnoid hemorrhage.
If an aneurysm is located, the following steps are taken to determine what type of treatment is needed. A CT scan is done to indicate whether there is bleeding, either into the tissue or the subarachnoid space. An arteriogram, an invasive test that allows for injection of a contrast dye into the vessels of the brain, is done in order to confirm the presence of the aneurysm. A lumbar puncture or "spinal tap" may be done if any of the above tests are inconclusive to positively rule out the presence of blood in the subarachnoid space.
Factors that doctors and researchers believe contribute to the formation of brain aneurysms:
- Smoking
- Traumatic Head Injury
- Use of Alcohol
- Use of Oral Contraceptives
- Family History of Brain Aneurysms
- Other Inherited Disorders: Ehler's Syndrome, Polycystic Kidney Disease, and Mar fan's Syndrome
Treatment
There are several ways to treat aneurysms based on the aneurysm’s size and location. If an aneurysm is small, has not ruptured and is in a difficult area to access, the patient is placed under observation.
However, if the aneurysm has ruptured, treatment options such as Surgical Intervention and Endovascular Intervention are available.
Surgical Intervention - a neurosurgeon performs surgery under general anesthesia, and can either clip the aneurysm, by placing a small microclip across the neck of the aneurysm, which prevents blood from entering into this weakened area; or "wraps" the aneurysm with a piece of muscle with a form of plastic to prevent the weakened wall from rupturing.
Endovascular Intervention- an interventional neuroradiologist performs an arteriogram in the radiology suite with the patient under general anesthesia. The aneurysm is located and a catheter is inserted to allow for the inside of the aneurysm to be sealed with special coils, preventing the aneurysm from filling with blood.
Aneurysm Web Resources
Aneurysm Outreach
Aneurysm Outreach, Inc. is a nonprofit organization dedicated to mobilizing people and resources to eradicate aneurysms.
Brain Aneurysm Foundation
The mission of the Brain Aneurysm Foundation is to provide support networks and educational resources to raise public awareness regarding early detection and treatment of brain aneurysms.
The Missy Project
Dedicated to raising awareness of Brain Aneurysm Disease in children through education, outreach and early detection.
1 The Brain Aneurysm Foundation
Seton is proud to have four hospitals – the only hospitals in Central Texas - that have earned the