Cavernous malformations


Find out about diagnosis and treatment options, including surgery, for these abnormal blood vessel formations of the brain and spinal column.


Cerebral cavernous malformations (CCMs) are abnormally formed blood vessels. As opposed to other kinds of hemangiomas, CCM vessels, which have the appearance of a small mulberry, develop and create problems in the brain or spinal cord. These malformations, which can vary in size from 2 millimeters to several centimeters in diameter, may be hereditary but most often occur on their own.

CCMs may leak blood, leading to bleeding in the brain or spinal cord (hemorrhage). Brain or spinal hemorrhages can generate a wide range of more apparent neurological symptoms, depending on the location of a cavernous malformation in a person's nervous system.


Cerebral cavernous malformations (CCMs) may exist without apparent symptoms. Obvious symptoms tend to occur when recurrent episodes of bleeding or blood clot formation lead either to seizures, for upper lobe CCMs, or to focal or vision issues, for CCMs in the brainstem, basal ganglia and spinal cord.

Generally, signs and symptoms of CCMs may include weakness, numbness, difficulty speaking, difficulty understanding others, unsteadiness, vision changes or severe headache. Seizures also can occur, and neurological issues can progressively worsen over time with recurrent bleeding (hemorrhage). Repeat bleeding can occur soon after an initial bleed or much later, or a repeat bleed may never occur.

When to see a doctor

Seek medical help immediately if you experience any symptoms of seizure, or signs and symptoms that suggest brain hemorrhage, such as:

  • Sudden, severe headache
  • Nausea
  • Vomiting
  • Weakness or numbness on one side of the body
  • Difficulties in speaking or understanding speech
  • Loss of vision
  • Double vision
  • Balance difficulties

Most CCMs occur as a single formation, without an apparent cause and without any family history.

However, roughly 20 percent of affected people have a familial (inherited) form of the disorder. In many cases, such people can identify similarly affected family members, most often with multiple malformations. A diagnosis of the inherited form can be confirmed by genetic testing.

Some CCMs can also occur following focal brain radiation therapy.


As mentioned above, while most CCMs occur with no clear cause, the genetic (inherited familial) form of the condition can cause multiple cavernous malformations, both initially and over time.

To date, research has identified three genetic variants responsible for familial cavernous malformations, to which almost all familial cases of cavernous malformations have been traced.


The most concerning complications of CCMs stem from recurrent bleeding (hemorrhage), which may lead to progressive neurological damage.

Hemorrhages are more likely to recur in people with prior diagnosed hemorrhages. They're also more likely to reoccur with malformations located in the brainstem.


Often, people with cerebral cavernous malformations (CCMs) don't show any signs or symptoms. Your diagnosis may result from brain imaging for other neurological conditions, or specific symptoms may prompt your doctor to pursue more extensive testing.

Depending on why the condition is suspected, doctors may order tests specifically to confirm CCMs, or to identify or rule out other related conditions. Brain imaging is also called for as soon as possible after the emergence of any new symptoms, to reveal either hemorrhage or the emergence of any new malformations.

  • Magnetic resonance imaging (MRI). In this test, a detailed picture is made of your brain or spine. The blood vessels in the brain may be imaged as well. Sometimes a doctor may inject a contrast dye into a vein in your arm to look at the brain tissue in a slightly different way, or to better look at the blood vessels in the brain (magnetic resonance angiography or magnetic resonance venography).
  • Genetic testing. If you have a family history of the condition, genetic counseling and tests are helpful to identify changes associated with CCMs in genes or chromosomes.

Doctors trained in brain and nervous system conditions (neurologists and cerebrovascular neurologists), brain and nervous system surgery (neurosurgeons), brain imaging (neuroradiologists), and other specialties work with you to treat CCMs as well as other neurological conditions.

Your treatment may include:

  • Observation. If you're not experiencing symptoms, your doctor may initially decide to monitor your cavernous malformation, especially since risk is generally lower for those who are non-symptomatic. Sometimes intermittent testing such as magnetic resonance imaging (MRI) is recommended to watch for any changes in the malformation. Let your doctor know right away about any changes in your symptoms.
  • Medications. If you have seizures related to a cavernous malformation, you may be prescribed medications to stop the seizures.
  • Surgery. If you're experiencing symptoms related to a cavernous malformation that can be reached surgically, your doctor may recommend surgery to remove the malformation.

If your treatment plan includes surgery, more advanced imaging technologies, such as functional MRI and tractography, may also be useful within specific contexts.

Potential future treatments

Several imaging technology areas hold promise for both improving predictions of the course of disease in some specific contexts and for enhancing the level of information available about a particular individual's disease state, including potential advances in imaging through quantitative susceptibility mapping (QSM), permeability imaging using dynamic contrast-enhanced MRI, and the use of alternative MRI contrast agents such as ferumoxytol. While still under investigation, such developments hold promise for enhanced imaging that may lead to more precise and effective clinical care in the future.


What you can do

  • Keep a detailed symptoms calendar. Each time a symptom occurs, write down the time, what you experienced and how long it lasted.
  • Write down key personal information, including any major stresses or recent life changes.
  • Make a list of all medications, vitamins or supplements that you're taking.
  • Take a family member or friend along. Sometimes it can be difficult to remember all the information provided to you during an appointment. Someone who accompanies you may remember something that you missed or forgot.
  • Bring along any recent brain scans in a CD to your appointment.

    Also, if you've experienced seizures, your doctor may want to ask questions of someone who has witnessed them, as it's common not to be aware of everything that happens when you experience one.

Write down questions to ask your doctor

Preparing a list of questions will help you make the most of your time with your doctor. List your questions from most important to least important in case time runs out. Most of these would be covered during your visit. Some examples of good questions to ask your doctor follow.

General questions

  • How many cavernous malformations do I have?
  • Where is it, or where are they located?
  • What functions do the area(s) of the brain perform?
  • Should my children (or anyone else in my family) be tested?
  • Should I have genetic tests for hereditary CCMs?

Management and observation

  • How often will I need follow-up tests?
  • How often will I follow up with you?

Surgery (to remove a malformation)

  • How long would you estimate I'd be in surgery?
  • How long does surgery recovery usually take?
  • How long should I plan to be in the hospital?

Surgical background

  • How many CCMs have you seen, and how many have you treated?
  • Does your institution have a cerebrovascular specialty practice?

Other questions may be useful for your particular needs. The Angioma Alliance website offers a more extensive set of suggested questions.

In addition to the questions you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.

What to expect from your doctor

Your doctor is also likely to ask you a number of questions:

  • When did you first begin experiencing symptoms (seizures, hemorrhage or bleeding, weakness in arms or legs, vision problems, balance problems, speech problems, difficulty with memory and attention, headaches, and so on)?
  • Do your symptoms come and go (intermittent) or are they persistent (present all the time)?
  • Do your symptoms seem to be triggered by certain events or conditions?

What you can do in the meantime

Certain conditions and activities can trigger seizures, so it may be helpful to:

  • Avoid excessive alcohol consumption
  • Avoid nicotine usage
  • Get enough sleep
  • Reduce stress


Last Updated:

December 24th, 2020

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