Aneurysm and AVM

What Is an Aneurysm?

An aneurysm is a balloon-like bulge in a blood vessel.  The walls of blood vessels are usually strong enough to withstand normal blood pressure. But weaknesses can be hereditary, or they can result from trauma. 

The Problem with Aneurysms

An aneurysm can enlarge with time. This enlargement can be aggravated by risk factors such as diabetes, alcoholism, obesity, tobacco use, hypertension, high cholesterol, and even increasing age. The aneurysm may eventually rupture (burst), or dissect (split). 

A rupture causes dangerous bleeding inside the body. A dissection in one or more layers of the artery wall causes bleeding into and along the layers of the artery wall, which can in turn lead to stroke.

Both rupture and dissection are extremely dangerous, and often fatal.

Symptoms of Brain Aneurysm

Most brain aneurysms produce no symptoms. These are sometimes discovered during tests for other, usually unrelated, conditions.

Sometimes an undetected aneurysm presses against parts of the brain, causing severe headaches, blurred vision, changes in speech, seizures, or neck pain. The symptoms depend on the part of the brain being pressed against, and the size of the aneurysm.

When a brain aneurysm ruptures, the symptoms can be abrupt. These symptoms should never be ignored; if you experience any of them, call emergency medical services immediately:  

  • A sudden, severe headache that is different from past headaches 
  • Neck pain 
  • Nausea and vomiting 
  • Sensitivity to light 
  • Fainting or loss of consciousness 
  • Seizures 

What is an AVM

AVM stands for Arteriovenous Malformation. An AVM is a tangle of abnormal and poorly formed blood vessels (arteries and veins). They have a higher rate of bleeding than normal blood vessels.

AVMs can occur anywhere in the body. Brain AVMs are of special concern because of the damage they cause when they bleed. They are very rare, and occur in less than 1% of the general population.

Symptoms of an AVM

While some AVMs cause no symptoms at all, others cause symptoms that are determined by their location and size. Common AVM symptoms include:

  • Seizures
    An AVM in the brain may act as an irritant, resulting in abnormal electrical activity. Seizures can develop as a result of this hyperactivity.
  • Headache
    Headaches may be caused by the high blood flow through the AVM . These headaches may become migraines, or migraine-like in intensity. Sudden, severe headaches can be caused by AVM bleeding. These headaches are often followed by nausea, vomiting, neurological problems such as paralysis or loss of speech, or a decrease in consciousness level.
  • Stroke-like symptoms
    Brain AVMs may deprive nearby brain tissue of oxygen and nutrients, causing symptoms such as:
    • weakness or paralysis on one side of the body 
    • numbness and tingling 
    • problems with vision, hearing, balance, memory, or even personality changes 
  • Bleeding
    This is the most serious complication of an AVM, and the main reason for recommending treatment. Brain AVMs bleed in roughly 4 out of 100 of those afflicted with them. Bleeds may be small and produce no noticeable symptoms. But approximately 50% of AVM bleeds cause permanent disability or death.


Aneurysms and AVMs are diagnosed in a variety of ways:

  • CT Scan
    Computed Tomography Scan (CT Scan or CAT Scan) uses radiologic imaging to produce a 3D picture of brain tissue. This scan is very helpful in diagnosing ruptured aneurysms and AVMs because it reveals blood in the brain tissue and under the brain membranes (meninges).
  • CT Angiogram
    This type of CT Scan utilizes contrast media to highlight blood vessel anatomy in the brain and neck. CT Angiogram is helpful for quickly diagnosing and ruling out unruptured aneurysms, and can help in the diagnosis of larger AVMs.
  • Cerebroangiogram
    During this procedure, a small catheter is put into an artery in the groin and sent up into the large arteries in the neck. Contrast media is then injected into the blood vessels, and radiographical images are produced to show the blood vessel anatomy and any possible aneuryms or AVMs that are present. This procedure is usually required before an aneurysm or AVM can be fixed by the neuroradiologist or neurosurgeon.

Neurointerventional Procedures

Stroke Center Video 2
Dr. Afshani explains the treatment of an AVM during a recent appearance on NBC30 News.
Click to play...

A variety of minimally invasive neurointerventional procedures are now available at Saint Francis Hospital and Medical Center. Led by Dr. Mansour Afshani, the Stroke Center Medical Director and Director of Interventional Neuroradiology, our team of highly trained professionals can assist in diagnosing and treating emergency and elective cases of aneurysm and AVM, as well as arterial venous fistulas (AVF).

  • Aneurysm coiling
    Some aneurysms can be treated using aneurysm coiling, a procedure which helps reduce the risk of aneurysm rupture. Aneurysm coiling is a state-of-the-art, minimally invasive procedure in which a catheter is inserted into the blood vessel via an artery in the groin, and microscopic platinum coils are inserted to permanently fill the aneurysm. These coils stabilize the aneurysm, reducing the chance of rupture and allowing the patient to enjoy normal activities.
  • Embolization of AVM
    Certain AVMs can be treated using a minimally invasive procedure called embolization. In this procedure, a catheter is inserted into the blood vessel via the groin, and a special substance is injected into the vessels supplying blood to the AVM. This procedure may reduce the chance of bleeding in smaller AVMs, negating the need for neurosurgery. In larger or more vascularized AVMs, embolization can be performed before a scheduled surgery for the purposes of reducing bleeding during surgery, as well as reducing post-surgery healing time.

Neurocritical Care

The Stroke Center at Saint Francis uses the latest technology to provide award-winning care to patients with stroke, aneurysms, AVMs, AVFs, and other blood vessel abnormalities. Our team of neurocritical care board-certified physicians, stroke-specialized acute care nurse practitioners, and highly trained, experienced ICU nurses will work together to bring you and your family the highest-quality care using the newest technologies available, with the personal touch that Saint Francis Hospital and Medical Center is known for.