Diagnosing a Cavernous Malformation

A cavernous malformation is a cluster of abnormal dilated blood vessels that lack normal blood vessel wall structure. As a result, blood flows through a cavernous malformation and can lead to bleeding into the brain. A mix of blood products leads to a characteristic “popcorn” appearance on imaging tests.   

The diagnosis of a cavernous malformation can be unexpected when the news comes after an imaging test for an unrelated reason. In other cases, it can be a long sought-out cause for disabling symptoms and the first step toward receiving appropriate treatment. Learn more about the diagnostic details surrounding cavernous malformations in this article.

Cavernous malformations are diagnosed using imaging tests such as a computed tomography (CT) scan and magnetic resonance imaging (MRI) test. A CT scan is cheaper and quicker than an MRI but provides less detail. These can be helpful to rule out other possible causes of your symptoms or to identify medical emergencies that require immediate action, such as a large brain bleed or blockage of fluid-filled cavities in the brain (hydrocephalus).

Although CT scans are handy for providing more immediate information about what is going on within the brain, an MRI is used to provide definitive diagnosis of a cavernous malformation. An MRI provides exceptional detail of the brain tissues and can display the characteristic “popcorn” appearance of a cavernous malformation.

An MRI is the most effective tool for finding and monitoring cerebral cavernous malformations. Instead of radiation used with CT scans, MRI uses magnetic fields to create a detailed picture of your brain or spine. The breakdown of blood within cavernous malformations is apparent on MRI and contributes to the characteristic “popcorn” appearance. Contrast dyes may also be used to search for other vascular abnormalities, such as developmental venous anomalies (DVAs), which can be associated with cavernous malformations.

About 20% of cavernous malformations develop for hereditary reasons, meaning patients inherit the condition from one or both parents. If there is a history of vascular malformations in your family, genetic screening and/or MRI screening may be advised.

A cavernous malformation is not a brain tumor or a brain injury. Rather, a cavernous malformation is simply an abnormal arrangement of blood vessel cells. Fortunately, most cavernous malformations do not affect life expectancy and are rarely life threatening.

Cavernous malformations and arteriovenous malformations (AVM) are both abnormal formations of blood vessels. The main difference between cavernous malformations and arteriovenous malformations is in their pressure and flow. Blood flows slowly in a cavernous malformation but rapidly in an arteriovenous malformation. Thus, rupture of a cavernous malformation typically causes fewer problems than an arteriovenous malformation, although prompt medical attention is still needed.

The differences in speed of blood flow also affect what imaging tests can be used to detect an arteriovenous malformation or cavernous malformation. An imaging test called an angiogram can detect blood vessel abnormalities when blood is seen flowing through the vessels. Angiograms can help to visualize and further characterize an arteriovenous malformation.

However, blood flow in a cavernous malformation is typically too slow to be observed and will not appear on an angiogram. Other tests such as CT and MRIs can be used for further assessment. Trained specialists can differentiate an arteriovenous malformation and cavernous malformation based on their characteristic appearance on imaging. 

Cerebrovascular neurosurgeons specialize in diagnosing and treating cavernous malformations. While you may have visited your primary physician for initial symptoms, they will refer you to a neurosurgeon to spearhead your care. Several specialists will likely work together to treat you as part of a comprehensive care team. In the case of a cavernous malformation, you may be treated by any of the following healthcare professionals:

• Neuroradiologist: Specializes in performing and interpreting radiologic imaging tests on the brain.
• Neurologist: Manages symptoms caused by cerebral cavernous malformations by medical means.
• Neurosurgeon: Evaluates you for surgical management (removal) of a cavernous malformation in your brain.
• Rehabilitation specialist: Helps you recover from physical symptoms of cavernous malformations, such as balance problems and muscle weakness.

If you are concerned about your health or are experiencing any symptoms, seek a medical professional right away. Your primary physician will be able to refer you to a specialist if needed. Obtaining an accurate and timely diagnosis is a critical first step toward appropriate treatment.  

Treatment of this condition varies depending on where the malformation is located, the severity of symptoms, and your age and general health. For asymptomatic cavernous malformations, a neurosurgeon may recommend simply observing it over time. If severe symptoms persist, treatment options such as surgery may be considered.

Do not hesitate to visit a healthcare provider if you have questions or concerns about any new symptoms that you are experiencing. Seeking a second opinion is also an option if the cause of the symptoms remains unclear.

• A cavernous malformation is an abnormal cluster of blood vessels in your brain or spine.
• Cavernous malformations can exist without symptoms, so some people can live years without knowing that they have a malformation until they undergo imaging tests for an unrelated disorder.
• Magnetic resonance imaging (MRI) is the most effective method for detecting a cavernous malformation.  

• Alliance to Cure Cavernous Malformation
• American Association of Neurological Surgeons
• National Organization for Rare Disorders