A brain aneurysm (AN-yoo-riz-um) is a bulge or ballooning in a blood vessel in the brain that can leak or rupture, causing bleeding into the brain (hemorrhagic stroke). Most often a ruptured brain aneurysm occurs in the space between the brain and the thin tissues covering the brain. This type of hemorrhagic stroke is called a subarachnoid hemorrhage.
A ruptured aneurysm quickly becomes life-threatening and requires prompt medical treatment.
Most brain aneurysms, however, don’t rupture, create health problems or cause symptoms. Such aneurysms are often detected during tests for other conditions. Treatment for an unruptured brain aneurysm may be appropriate in some cases and may prevent a rupture in the future.
A number of factors can contribute to weakness in an artery wall and increase the risk of a brain aneurysm. Brain aneurysms are more common in adults than in children and more common in women than in men.
Some of these risk factors are:
- A condition you are born with (congenital (con-JEN-it-ul) defect)
- High blood pressure
- Hardening of the arteries (atherosclerosis, pronounced ath-er-o-sklair-OH-sus)
- Brain injury
- Certain blood infection
- Drug abuse, particularly the use of cocaine
- Head injury
- Heavy alcohol consumption
- Certain blood infections
- Lower estrogen levels after menopause
An unruptured brain aneurysm may produce no symptoms, particularly if it’s small. However, a large unruptured aneurysm may press on brain tissues and nerves, possibly causing:
- Pain above and behind an eye
- A dilated pupil
- Change in vision or double vision
- Numbness, weakness or paralysis of one side of the face
- A drooping eyelid
A sudden, severe headache is the key symptom of a ruptured aneurysm. This headache is often described as the “worst headache” ever experienced.
Common signs and symptoms of a ruptured aneurysm include:
- Sudden, extremely severe headache
- Nausea and vomiting
- Stiff neck
- Blurred or double vision
- Sensitivity to light
- A drooping eyelid
- Loss of consciousness
A CT scan of the head is done to look for blood in the brain. If the CT scan does not show the problem, a lumbar puncture and angiogram are done. A lumbar puncture (also called a spinal tap) looks for blood in the fluid inside the spine. This fluid is called CFS, or cerebrospinal (ser-EE-bro-spi-nal) fluid. Blood in the fluid means there may be a subarachnoid hemorrhage.
An angiogram is done to show the exact location of the aneurysm. A catheter (thin tube) will be placed into a blood vessel in your neck. Through this, a dye will be injected into these vessels. The dye shows up on an x-ray, and if there is any bleeding, it will appear.
A person with a ruptured cerebral aneurysm needs medical attention right away. The patient may need surgery. The surgery is called a clip ligation (lie-GAY-shun). During the surgery, a metal clip is placed at the base of the aneurysm to control the bleeding and to decrease the risk of more bleeding. More bleeding can mean more brain damage.
In some cases, the surgeon will suggest a procedure that blocks the blood vessel so that blood can no longer flow through it. This procedure is called an endovascular (en-doe-VASS-kue-ler) embolization (em-bo-liz-AY-shun). Metal coils are packed into the aneurysm through a catheter that is inserted into the groin. This procedure is done by a radiologist who is specially trained in this type of procedure. The procedure will be done in the radiology department.