Conditions & Topics

A cerebral aneurysm (also called an intracranial or intracerebral aneurysm) is a weak or thin spot on a blood vessel in the brain that balloons out and fills with blood. A bulging aneurysm can press on a nerve or surrounding brain tissue, but the major concern is that it may rupture and bleed into the brain. Some aneurysms — especially tiny ones — cause no problems and carry a low risk of bleeding.

Brain aneurysms can develop in anyone at any age, are more common in adults than children, and slightly more common in women. People with certain inherited disorders (such as polycystic kidney disease and connective tissue disorders) are at higher risk. Reported ruptured aneurysms occur in about 10 per 100,000 people per year, most commonly between ages 30 and 60. Risk factors for rupture include smoking, high blood pressure, and alcohol or drug abuse.

A rupture can bleed around the brain (a subarachnoid hemorrhage), leading to hemorrhagic stroke, permanent nerve damage, or death. Once ruptured, an aneurysm has a high chance of rupturing again, which is why we treat ruptured aneurysms quickly. Complications can include hydrocephalus (fluid buildup) and vasospasm (narrowing of other brain vessels that limits blood flow), both of which can cause further injury.

Most aneurysms cause no symptoms until they grow large or burst. A larger, growing aneurysm may press on nerves affecting the eyes and vision. When an aneurysm hemorrhages, a person may have a sudden, extremely severe headache — often described as “the worst headache of my life” — along with double vision, nausea, vomiting, a stiff neck, a drooping eyelid, light sensitivity, changes in awareness, seizures, or loss of consciousness. Anyone experiencing this should seek immediate medical attention.

There are two main surgical options. Microvascular clipping involves removing a section of skull, locating the aneurysm under a microscope, and placing a small metal clip across its neck to stop blood flow into it. Endovascular coil embolization threads a catheter from an artery in the leg up to the aneurysm and releases platinum coils that fill it and block it off from circulation. The best choice depends on the aneurysm’s type, size, and location, and on the patient’s age, health, and history.

Endovascular coiling typically takes about 1½–3 hours, and aneurysm clipping about 4–5 hours. General anesthesia is used for clipping and most coiling procedures, with a neuro-anesthesiologist present throughout.

It depends greatly on whether the aneurysm has ruptured. Patients with unruptured aneurysms usually stay about 2–3 days depending on treatment. For a ruptured aneurysm (subarachnoid hemorrhage), the stay varies with the severity of the bleed and the patient’s condition on arrival — in severe cases, from about 14 days to a month.

Most clipping incisions heal in about six weeks; sutures may dissolve over several weeks or staples are removed after about two weeks. After coiling, the groin puncture site heals quickly. Most clipping patients are off pain medication within 1–3 weeks. Patients with unruptured aneurysms usually wait about two weeks before driving; those treated by coiling can often drive sooner. After coiling, imaging follow-up (MRA or angiography) is needed to confirm the aneurysm stays sealed, sometimes up to five years; most clipping patients do not need further imaging.

Yes. All titanium clips and platinum coils used are MRI compatible.

When more than one family member has been diagnosed with an aneurysm, it is recommended that other family members talk with their physicians about non-invasive screening, such as MRA or CTA.