An intracranial aneurysm, also known as a cerebral aneurysm, is a blood vessel within the brain that bulges or expands like a balloon and fills with blood. Caused by a weakness in wall of an artery, an intracranial aneurysm may lead to pressure on surrounding nerves and tissue, and an increased risk of rupture or hemorrhage. While this condition can occur anywhere within the brain, intracranial aneurysms most commonly affect the arteries from the underside of the brain to the base of the skull. Intracranial aneurysms can affect individuals of all ages, but are more common in adults than children, and seem to affect women more than men.

An intracranial aneurysm is caused by a weakening in the wall of a cerebral artery. Factors that may contribute to the formation of intracranial aneurysms may include:

• Smoking
• High blood pressure
• Cocaine use
• Family history of intracranial aneurysms
• Tumors
• Head injury
• Infection

Older age and heavy alcohol consumption may also put individuals at risk for developing intracranial aneurysms.

Patients with an intracranial aneurysm may not experience any symptoms until the aneurysm grows larger or bursts,and puts pressure on tissues and nerves in the affected area. Symptoms may include:

• Pain behind the eye
• Facial weakness or paralysis
• Vision changes
• Severe headache
• Confusion
• Nausea and vomiting
• Loss of consciousness

A ruptured aneurysm may cause bleeding within the brain and can lead to serious complications, including nerve damage, stroke or even death. It is essential to seek medical attention at the first sign of symptoms.

Many patients are unaware that they have an intracranial aneurysm and it may sometimes be diagnosed accidentally when imaging tests are performed for other conditions. If an intracranial aneurysm is suspected, symptoms will be reviewed and a full physical examination will be performed. In order to confirm a diagnosis and assess the severity of an intracranial aneurysm, additional diagnostic tests may include:

• Angiography
• CT scans
• MRI scan

A cerebrospinal fluid analysis may also be performed to test the cerebrospinal fluid and determine if the patient has symptoms of a ruptured intracranial aneurysm.

Treatment for an intracranial aneurysm varies depending on each patient’s individual condition, as well as the and size and risk of rupture of the aneurysm. Not all aneurysms will burst, and those that are small may only require routine monitoring to detect any growth or symptoms. Common treatment options for this condition include procedures that divert blood flow away from the aneurysm and eventually cause it to disappear. Procedures may include:

• Microvascular clipping
• Occlusion
• Endovascular embolization

Additional treatment may include medication to control symptoms and treat pain and may include pain relievers, calcium channel blockers, or anti-seizure medications.

• MedlinePlus
• National Institutes of Health
• Centers for Disease Control and Prevention
• Eunice Kennedy Shriver National Institute of Child Health and Human Development
• U.S. Department of Health & Human Services
• U.S. National Library of Medicine
• WebMD