A cerebral aneurysm is a common cerebrovascular disorder caused by a weakness in the wall of an artery that supplies blood to the brain. This weakening results in an abnormal widening or ballooning of the artery, and increases the risk for a subarachnoid hemorrhage; a rupture or bursting of the aneurysm. The most common location for brain aneurysms is in the network of vessels at the base of the brain. The disorder may result from congenital defects, preexisting conditions such as high blood pressure, a history of smoking, a family history of brain aneurysms, or from head trauma. Brain aneurysms occur more commonly in adults than in children and are slightly more common in women than in men, however they may occur at any age.


Most brain aneurysms cause no symptoms and can go undetected. In some cases, an un-ruptured aneurysm will press on surrounding areas in the brain, causing headaches, blurred vision, changes in speech or neck pain. When an aneurysm ruptures, symptoms such as acute headache, neck pain, and nausea and vomiting, will be severe and come on suddenly. Additional symptoms may include sensitivity to light, fainting or loss of consciousness, and seizures. Rupture of a cerebral aneurysm is dangerous and usually results in bleeding within or surrounding the brain. Sometimes, individuals will experience recent “warning” headaches that have lasted for days or weeks prior to the hemorrhage. Re-bleeding, hydrocephalus (the excessive accumulation of cerebrospinal fluid), vasospasm (spasm of the blood vessels), or multiple aneurysms may also occur.


Since most un-ruptured brain aneurysms rarely cause symptoms, it’s likely the aneurysm will only be discovered while being diagnosed for an unrelated condition. However, if your doctor suspects you have a brain aneurysm, or an aneurysm has burst, your doctor will want to identify, as quickly as possible; how much blood has leaked out of the burst artery, the size, shape and location of the aneurysm, the size and blood flow of the affected artery, and any additional affected tissue. Diagnosis will begin with a rapid non-contrast computed tomography (CT) scan, sometimes followed by a lumbar puncture. In addition, you may also undergo a computed tomography angiogram (CTA) scan, magnetic resonance angiogram (MRA) or a formal digital subtraction cerebral angiogram (DSA). Sometimes additional tests will be performed using a blood draw or chest x-ray.


At Stanford, we have been at the forefront of developing new, minimally invasive techniques, such as microsurgical clipping and endovascular approaches, which treat the aneurysm from inside the blood vessel. When aneurysms get very large or have complex anatomy they can be particularly difficult to treat and require specialized techniques. Depending on the size, location, and status of an aneurysm, doctors may perform microsurgical clipping, endovascular coiling embolization or stent placement, arterial bypass or a combination of these techniques. Emergency treatment for individuals with a ruptured brain aneurysm generally includes restoring deteriorating respiration and reducing intracranial pressure, followed by endovascular or surgical treatment. Other therapy may include bed rest, drug therapy, or hypertensive-hypervolemic therapy. Since each brain aneurysm is different, treatment is determined through careful consideration by your care team based on several factors, including; your age, overall health, extent of the condition, your tolerance for certain medications, etc.


By The Numbers:

At Stanford, we have extensive experience over several decades, of treating aneurysms. Between 1989 and July 2017, we treated a total of 3,462 aneurysms (2,351 treated via surgery and 1,111 treated via endovascular procedures).