Aneurysms are weak spots in the walls of arteries that balloon out over the course of years. These balloons have walls that are thinned out enough that they can rupture, causing severe bleeding in or around the brain.

No one knows why the majority people who have brain aneurysms get them. About 2% of the American population have aneurysms. Certain conditions may predispose you to develop brain aneurysms such as polycystic kidneys, systemic lupus erythematosus, Erhlers Danlos syndrome or occasionally hypertension. For the most part, a ruptured aneurysm can only be ascribed to bad luck, and only very occasionally do aneurysms run in families.

Brain aneurysms cause problems in two general ways. The first and most life threatening is bleeding. This results in the rapid onset of a severe headache and may be associated with transient loss of consciousness. The headache is usually followed by neck stiffness, back pain, nausea or vomiting, and an inability to tolerate bright light. This situation constitutes an emergency, and immediate medical care must be sought. The second (much less common) way aneurysms cause problems is if they reach such a large size that they cause pressure on the brain or nerves. This situation may cause a seizure, drooping eyelid, dilated pupil, double vision, progressive blindness in one eye, or numbness on one side of the face.

Unfortunately, unless aneurysms cause one of the above mentioned problems, there is no way to know that you have one. Occasionally they are discovered "accidentally" when a CAT scan or MRI scan is performed for other reasons. Brain aneurysms are truly silent killers.

The bleeding that occurs inside the head when an aneurysm bursts can cause severe brain damage or even death. Over 30% of people will die within the first few days after a hemorrhage. Of the remaining 70%, less than half will ever return to their normal activities. For the lucky ones who survive the first hemorrhage, several important considerations must be met. First, steps must be taken to make sure the aneurysm does not burst again. If it does there is a 70% chance of death. Second, brain damage from pressure inside the head must be avoided. Third, treatment must be given to avoid cerebral vasospasm, a condition that can cause stroke or further brain damage one to two weeks after the aneurysms bursts.

They think they found an aneurysm on my CAT scan or MRI scan. What is the next step?

In order to determine for sure if you have an aneurysm, a cerebral angiogram (arteriogram) or   CT- angiogram must be performed. A cerebral angiogram is performed in the hospital under local anesthesia. A catheter is placed in a leg artery and passed through the arteries leading to the brain. Dye is injected and multiple 2 dimensional X-rays are taken of the brain blood vessels. CT-angiogram is a CT scan that demonstrates 3 dimensional images of these same blood vessels. This is performed in the CT scanner after contrast dye is injected into an arm vein. There is no anesthesia required for this study. Only with these tests, which have a small amount of risk, can your surgeon determine the location, size and risk of your aneurysm.

Not all aneurysms will rupture. The International Study of Unruptured Aneurysms (ISUIA) suggested a rupture rate of between 0.05 and 0.5% per year. Previously it was thought that the rupture rate was closer to 2-3% per year. Clearly, larger aneurysms, those with irregular shape, and those on the vertebral-basilar circulation may be more dangerous. A frank discussion with your surgeon will help you balance the risks and benefits of treating the aneurysm.

Unruptured Aneurysm Study

The most successful form of therapy is a surgical procedure that places a clip across the base of the aneurysm so it no longer fills with blood. This is a technically demanding but highly successful procedure done through an operating microscope using state-of-the-art instrumentation. The Neurovascular Division of USC's Department of Neurological Surgery has successfully managed over 2000 of these cases.









An alternative to surgical treatment involves coil embolization of the aneurysm. This technique has been and continues to be
developed at USC. Many aneurysms are now being treated by packing them full of soft platinum coils. This technique is performed through a catheter inserted through an artery in the groin. It has the obvious benefit of avoiding a craniotomy. As experience with this technique grows, more brain aneurysms are able to be treated this way. Currently half of the aneurysms are treated this way at USC.

For those aneurysms with even greater complexity, a number of techniques and medical disciplines can be summoned in order to obliterate these lesions in a safe and effective manner. Those techniques include balloon test occlusion, neurophysiologic monitoring, bypass grafting the affected artery, reconstructing the affected artery, and the use of hypothermic cardiac arrest. Because the techniques and personnel needed to deal with these multi-disciplinary and complex conditions reside in one department (USC Department of Neurological Surgery), decision making regarding the best course of action for each individual case is facilitated.

This depends on a number of factors including pre-existing brain damage, age and health of the patient, location and size of the aneurysm and whether or not the aneurysm has ruptured. Because of the experience of USC's team, success rate for certain types of aneurysms is 95% or greater. Only teams that specialize in this type of surgery can be expected to attain such results.

Hospital-Related Factors vs. Cerebral (Brain) Aneurysm Outcomes
Number of Cases vs. Cerebral (Brain) Aneurysm Outcomes
Incidental Aneurysms

Yes, it is. It is possible that your surgeon can give you names of people who have made a similar decision, and who would be willing to talk to you regarding your treatment.

For further information or to schedule an appointment please contact the Neurosurgery Clinical Office at (323) 442-6290

They found my aneurysm before it burst.

The $50,000 Haircut: The true story of one man's struggle and triumph over an unruptured aneurysm.