Brain Aneurysms

A brain aneurysm (sometimes called cerebral aneurysm) is an abnormal bulging or ballooning portion of a weakened blood vessel that is located in the brain. The larger the bulging becomes, the more likely the brain aneurysm will bleed into and around the brain. When brain aneurysms bleed, they cause sudden death in half of the patients. Those who survive only remain functionally intact less than half of the time. Brain aneurysm bleeds cause strokes that can seriously impair speech, motor, and sensory function.

Mount Sinai’s Cerebrovascular Center has FDA and IRB approval to use newly developed technologies – many available at no other centers in New York – in order to treat brain aneurysms that were otherwise untreatable. Our team is well-recognized for providing the highest quality care and having access to the most ground-breaking treatments.

Who Is At Risk For Brain Aneurysms?

Factors that increase the risk for brain aneurysms and associated symptoms include:

  • Age
  • Family or personal history of brain aneurysms
  • Certain conditions such as polycystic kidney disease and connective tissue disorders
  • Smoking

Brain Aneurysm Types

Brain aneurysms cause a bulging in the wall of the blood vessel. This bulge can take two general shapes. The first is called a "saccular" brain aneurysm, and it is a formation of a sac or pouch on one side of the blood vessel wall. The second type is called a "fusiform" brain aneurysm, and it is an outward bulging of the blood vessel wall in all directions.

Along with occurring within the brain itself, an aneurysm can occur in the major head and neck vessels leading to the brain, called the carotid arteries, with the same devastating results. The carotid arteries are the vessels in your neck forward of the large neck muscle on the side of your neck which can be felt pulsing.

Brain Aneurysm Symptoms

Most people with unruptured brain aneurysms experience little or no symptoms. In some instances, people experience indications of an aneurysm before rupture, including:

  • A "warning" headache that may occur several days or weeks before the rupture
  • A dilated pupil in one eye
  • Problems with vision or eye movement
  • Pain above or behind the eye, or in the temple, back of the head, or neck

Brain aneurysm symptoms more typically occur when an aneurysm ruptures. This is considered an emergency situation and requires immediate emergency care. The first wave of symptoms of a ruptured brain aneurysm typically includes:

  • Severe headache – even if prone to headaches or migraines, this will feel very different from the norm
  • Neck stiffness
  • Nausea
  • Vomiting
  • Sensitivity to light

These brain aneurysm symptoms are often immediately followed by:

  • Confusion or change in mental state or consciousness
  • Coma
  • In some cases, seizures

Treatment Options for Brain Aneurysms

At Mount Sinai, we are often able to identify the presence of an aneurysm and treat it before rupture. We use endovascular techniques (embolization) or microsurgery (aneurysm clipping)  to prevent a disastrous rupture.


During embolization, we use angiogram techniques to treat the aneurysm from inside the blood vessel. We pack the aneurysm with small detachable coils, so it can no longer fill up with blood. Our team at Mount Sinai has embolized more than 1,000 brain aneurysms. We are experts in both stent- and balloon-assisted coil embolization, as well as the most modern techniques available, including flow diversion.

In contrast to conventional open surgery, this technique allows the aneurysm to be treated from the inside of the vessel, thus the name "endovascular" surgery. Endovascular embolization can be used to treat aneurysms in many locations and has been shown to be particularly useful in treating aneurysms that are very difficult or impossible to reach by conventional neurosurgical techniques.

Aneurysm Clipping

As an alternative to embolization, we might place a surgical clip around the neck of the aneurysm to prevent blood from flowing into it. This involves an open surgical procedure, however, in some cases, this is the preferred approach. We have pioneered minimally invasive ways to perform these surgical clippings, resulting in less tissue injury, better cosmetic results, and fast recovery times than traditional procedures.

Contact Us

Cerebrovascular Center
Klingenstein Clinical Center, 1-North
1450 Madison Avenue
New York, NY 10029

Phone: 212-241-3400
Fax: 646-537-2299