Disorder Definitions

  • Cerebral Cavernous Malformations (CCM)
  • Sturge-Weber Syndrome (SWS) - Leptomeningeal Angiomatosis
  • Hereditary Hemorrhagic Telangiectasia (HHT) - Brain Arteriovenous Malformation (BAVM)

Cerebral Cavernous Malformations (CCM)

What are Cerebral Cavernous Malformations?

Cerebral Cavernous Malformations, also termed Cavernous Angioma and Cavernoma, is a disorder that affects the vascular system (blood vessels) by causing vascular malformations in the brain and spine. Individuals affected by CCM may experience a variety of symptoms ranging from headaches to neurological deficits, seizures and/or stroke.

Some people with CCM have no symptoms, while others may have serious symptoms such as seizures (most common), headaches, paralysis, hearing or vision changes, and bleeding in the brain (cerebral hemorrhage). Not everyone with CCM is affected in the same way. Some patients have mild disease, while others may have severe bleeding in the brain, which can be life-threatening.

The two types of CCM are familial (inherited) and sporadic (occurring for no clear reason).


Who gets Cerebral Cavernous Malformations?

Approximately 0.5 percent of the general population is affected by cerebral cavernous malformations. CCM occurs in both men and women and can affect children and adults.

What causes Cerebral Cavernous Malformations?

CCM may be inherited due to mutations in one of three genes, CCM1, CCM2, or CCM3 – individuals with this inherited form typically have multiple CCM lesions. Alternatively, single lesions are often seen in patients with the sporadic (non - genetic) form of CCM.

How is Cerebral Cavernous Malformations Diagnosed?

Magnetic Resonance Imaging (MRI) is used to detect CCM lesions and diagnose the illness. Alternatively, genetic testing is available to diagnose the inherited form of CCM.

What is the treatment for Cerebral Cavernous Malformations?

Treatment for Cerebral Cavernous Malformations often varies depending on symptoms.

Treatment plans may include:

  • Observation. No further studies unless clinical condition changes but regular follow-up and update visits annually or as needed to review seizure history and headache history and to recommend lifestyle changes such as weight loss, daily exercise, improvement in sleep hygiene, avoidance of triggers or to advise on medical disorders that may impact CCMs such as blood clotting disorders, hypertension, need for chemotherapy or radiation.
  • Imaging. Doctors monitor the cavernous malformation with yearly MRI (magnetic resonance imaging) scans to see if the malformation changes. This is typically the case when the malformation is found during tests for other conditions and isn't causing problems.
  • Medication. If the CCM causes symptoms, medication for the specific symptom may be used. For example, Seizures are usually treated with antiepileptic drugs. Headaches may be treated with lifestyle changes (weight loss, daily exercise, improvement in sleep hygiene, avoidance of triggers), medications for symptomatic relief, or with medications to reduce the frequency of headaches, reduce the duration of headaches, or to reduce the severity of headaches.
  • Surgery. If one of the CCMs is causing specific and related symptoms and is in a location that can be reached surgically, surgical consultation may be recommended. Surgery may be required to treat acute hemorrhage and brain swelling that is life threatening or that is likely to cause neurological injury.
  • Stereotactic radiosurgery. Doctors may use stereotactic radiosurgery (targeted radiation) to treat malformations causing symptoms and that are located in areas of the brain that can't be treated with surgery. This may decrease the repeat hemorrhage rate. However, radiosurgery hasn't been shown to completely eliminate malformations and there is growing concern that radiation may increase lesion development.

Frequently Asked Questions about CCM


I have Cerebral Cavernous Malformations, are my children at risk?

If you have the sporadic form of CCM (you have a single lesion and no family history of CCM), then your children are unlikely to have an increased risk of developing CCM.

If you have the familial form of CCM (you have multiple lesions, and/or a family history of CCM), then each of your children will have a 50% chance of carrying or being affected by the illness.

Sturge-Weber Syndrome (SWS)

What is Sturge-Weber Syndrome?

Sturge-Weber Syndrome (SWS) is the association of a facial port-wine birthmark with abnormal vessels on the surface of the brain, glaucoma, or both. The presence of a port-wine birthmark involving the forehead or upper eyelid raises the suspicion of SWS. These infants and children must be followed closely for other medical issues, including vision problems, epilepsy, and developmental delays. It can affect one side (in about 85%) or both sides (in about 15%) of the body or brain.


Who gets Sturge-Weber Syndrome?

SWS does NOT run in families. SWS occurs almost equally in boys and girls around the world who have a port wine birthmark around the eye and forehead region of the face.


What causes Sturge-Weber Syndrome?

The underlying cause of SWS is a somatic mutation in the GNAQ gene. The extent of involvement varies greatly from patient to patient, probably depending on the location and timing of this mutation during fetal development. More research is needed to understand this mutation, how to use that knowledge to treat SWS, and how to prevent the medical and developmental problems resulting from it.


How is Sturge-Weber Syndrome diagnosed?

The typical diagnosis of SWS depends on a facial port-wine birthmark combined with glaucoma (increased pressure in the eye) and abnormal blood vessels in the brain. Neurologic, ophthalmologic, dermatologic and other evaluations are therefore recommended to make the diagnosis of SWS and screen for associated complications. However, SWS is a spectrum disorder, and therefore individuals can have brain involvement only, eye involvement only, or skin involvement only; likewise patients can have any combination of the two structures involved. Infants are born with the port-wine birthmark, and a dermatologic evaluation can confirm that the birthmark is a port-wine birthmark. Seizures, early handedness or evidence of a visual gaze preference usually begin in the first two years of life. EEG and MRI imaging of the brain (with contrast) can make diagnosis of brain involvement, but imaging may not detect it until after 2 years of life. Neurological symptoms occasionally start in infancy but can start later childhood or even in adulthood. Glaucoma has two peak periods: the first in infancy and the second in young adulthood. However, glaucoma can begin at any time and at-risk individuals should be examined by an ophthalmologist every few months for the first few years and then at least annually for life.


What is/is there treatment for Sturge-Weber Syndrome?

Treatment has been largely symptomatic and hampered by delayed diagnosis and the rarity of the syndrome. Typically, for the brain involvement causing seizures, the use of anti-convulsant medications is necessary. Ischemic strokes and migraine headaches are also treated. If diagnosed promptly, treatment can save cognitive functioning and lessen the impact of physical limb weakness. However, it can be a progressive syndrome, and varying degrees of presentation can be expected depending on the age of seizure onset. Low dose aspirin is another treatment option utilized by some patients. Eye involvement is treated with drops or surgery to decrease the pressure. The birthmark is treated with laser treatment.

Frequently Asked Questions about SWS

SWS is not caused by a gene defect that is carried in the sperm or egg of a parent. It is caused by a spontaneous mistake (mutation) of the GNAQ gene in one cell at some time after conception has occurred. This cell with the SWS somatic mutation occurring early in fetal development continues to divide and passes the mutation on to the "daughter" cells created in that area of the body. These cells have the mutation and the rest of the body does not. Since the parents are not "carrying" the disease, then the chances of another child having SWS are no higher than they would be for any other parents.
A classical diagnosis of SWS includes brain involvement with the abnormal blood vessels-although the term can also refer to those who have skin and eye involvement but no brain involvement at all. Often it is easiest to refer specifically to the type of involvement the individual has, i.e. "Sturge-Weber syndrome brain and skin involvement" or "Sturge-Weber syndrome brain involvement only" etc. Even in those with brain involvement, the degree to which the brain is "damaged", if at all, varies from one individual to another. Some people have blood vessel abnormalities in the brain without seizures, intellectual impairment, or any obvious impact.
Some children with stroke-like episodes eventually develop permanent weakness, but many regain use of the limb within 72 hours of the onset of weakness. Most of the episodes occur at the time of seizures and treatment is directed toward the associated seizures. Permanent weakness is more likely to occur in infants and young children. If you detect what appears to be the sudden onset of weakness in an arm and hand, leg, or face, seek immediate medical attention.
No. However, everyone with SWS should be checked regularly by an ophthalmologist. We recommend check-ups every 3 months in the first year of life. Glaucoma may occur with no symptoms at all until it is too late to salvage vision. Routine screening is very important, even if there are no symptoms at all. Telltale signs include a bulging, pain, or excessive watering of the eye (usually the one involved with PWS). Glaucoma can start at any time so monitoring should continue at least yearly for life.
If left untreated, capillary vascular malformations may develop problems later in life, typically around the 3rd to 4th decade. Over time they may thicken, darken or develop nodules (bumps). Current practice is to treat the malformation with a laser at a very young age. One of the benefits of treating an infant is that the surface area is smaller and can be treated with fewer repeated procedures. However, reducing the size and appearance of the skin lesions DOES NOTHING for the eye and brain complications of SWS.
Capillary vascular malformations treated by laser can reoccur with time and may need maintenance treatments periodically to prevent re-darkening of the birthmark.
The Port-Wine birthmark grows commensurate (along with) the child. The PWS may become thicker or produce bumps and nodules in time, but the involved area will not extend or become greater.

Hereditary Hemorrhagic Telangiectasia (HHT)

What is Hereditary Hemorrhagic Telangiectasia?

Hereditary Hemorrhagic Telangiectasia, also known as Osler-Weber-Rendu Syndrome, is a hereditary disorder that affects the vascular system (blood vessels). People with HHT develop abnormal blood vessels (arteriovenous malformations or AVMs) that lack the capillaries that are usually present between each artery and vein. In the AVMs, the arterial blood flows directly into a vein without first having to squeeze through the small capillaries. These AVMs tend to be fragile and can rupture and bleed. The smaller AVMs are called telangiectasia and occur primarily in the nose, mouth, and skin of the face and hands, as well as the lining of the stomach and intestines. The larger abnormal blood vessels (AVMs) occur in the brain, lung, liver and spine.

Telangiectases in the nose, along with the nosebleeds they cause, are the most common features of HHT. About 90% of people with HHT have recurring nosebleeds by the time they reach middle age. They range from mild to severe and can cause an individual to require regular blood transfusions. Telangiectases of the skin of the hands and face, as well as of the lining of the lips and mouth are found in 90% of all people with HHT. However, these often do not become apparent until the 30’s or 40’s.

Bleeding from the stomach and bowels (gastrointestinal or GI bleeding) will develop in 30% of people with HHT. The GI bleeding in HHT can range from mild to severe and can cause an individual to require regular blood transfusions. Telangiectases in the stomach and bowels do not cause pain or discomfort. Most HHT patients with GI bleeding don’t have symptoms but are anemic or iron deficient. Sometimes they can have black or bloody stools as well. Anemia can cause fatigue, shortness of breath, chest pain or lightheadedness.

Lung AVMs are found in approximately 40% of people with HHT and they are often multiple. AVMs in the lung are at risk of rupturing, particularly during pregnancy. This can lead to life-threatening hemorrhage. In addition, people with untreated lung AVMs, loose the capillary ability to filter for impurities (clots, bacteria, air bubbles) from the blood before the blood circulates to the brain. As such, people with lung AVMs are at risk of stroke and brain abscess, which can be debilitating and life-threatening. Lung AVMs can be effectively treated with a procedure called transcatheter embolization. People with lung AVMs may be short of breath and easily fatigued and suffer from migraine headaches, but sometimes they have no symptoms before developing stroke or hemorrhage.

Brain AVMs are present in approximately 10% of people with HHT. They can hemorrhage and cause stroke and/or death, or can lead to seizures. Brain AVMs can be treated, but expert care is required. Spinal AVMs are very rare but can also hemorrhage. These can be treated similarly to brain AVMs.

Liver AVMs are present in 75% of HHT patients, but only cause symptoms in about 7% of people with HHT. They are unlikely to rupture, and most do not require treatment. When they are large and numerous, they can cause heart and liver failure, usually later in life.

It is unlikely that a person with HHT will have all of the symptoms and AVMs described. One of the characteristics of HHT is its variability, even within a family. One cannot predict how likely someone is to have one of the hidden, internal AVMs based on how many nosebleeds or skin telangiectases one has. Additionally, some people will have mild disease while others, even within the same family, may have severe bleeding in internal organs which can be life threatening.


Who gets Hereditary Hemorrhagic Telangiectasia?

HHT occurs in children and adults, men and women and affects all ethnicities.


What causes Hereditary Hemorrhagic Telangiectasia?

HHT is caused by defects in at least 3 genes, but only one abnormal gene is the cause in one family. The abnormal gene found on Chromosome 9 is called endoglin and causes HHT1. The abnormal gene on Chromosome 12 is called activin-like kinase 1 (ALK1) and causes HHT 2. Endolgin and Alk1 are through to cause most of the HHT cases. The third gene, MADH4, causes symptoms in HHT and multiple colon polyps at an early age. Most people with MADH4 mutation have combined HHT and Juvenile Polyposis. It is thought that two other abnormal genes, found on Chromosome 5 and 7 can cause HHT: the genes have yet to be discovered. HHT is considered an autosomal dominant disorder, which means that each child born of an HHT affected parent will have a 50% chance of inheriting the abnormal gene.


How is Hereditary Hemorrhagic Telangiectasia diagnosed?

HHT can be diagnosed through genetic testing and/or by clinical criteria (the Curacao Criteria). These criteria include:

  • Nosebleeds that are spontaneous and recurrent that can be mild or severe
  • Multiple telangiectases on the skin or in the mucous membranes. The telangiectases are small red spots that blanch under pressure located on the lips, oral cavity, fingers, palm of the hands and nose.
  • Arteriovenous malformations (AVMs) or telangiectases in one or more of the internal organs, including the lungs, brain, liver, intestines, stomach, and spinal cord. A first-degree relative (brother, sister, parent or child) with HHT, based on these diagnostic criteria.

A diagnosis is considered definite when 3 or more of the criteria are present, possible or suspected when 2 findings are present, and unlikely with fewer than 2 findings.

Learn more about diagnosis of HHT in the International HHT Guidelines.


What is the treatment for Hereditary Hemorrhagic Telangiectasia?

Treatment of a person’s HHT depends on which parts of the body are affected. Some aspects (nosebleeds) are treated symptomatically, whereas others are treated preventatively (lung and brain AVMs).

Treatments for nosebleeds can range from lubrication of the nasal mucosa, laser therapy and septal dermoplasty for severe transfusion dependent patients. Telangiectases of the skin can be treated with laser therapy.

Lung and brain AVMs should be treated before they cause complications. Lung AVMs can almost always be treated completely with embolization, a high-tech low-risk procedure. Brain AVMs are treated in different ways depending on the size, structure and location in the brain. Surgery, embolization and stereotactic radio surgery can all be used, separately or in combination to successfully treat brain AVMs.

Bleeding from the stomach or intestines is generally treated only if it causes anemia (low blood count). Iron replacement therapy is the first line of defense. If iron therapy does not control the anemia, transfusion and endoscopic treatments using a heater probe, APC or laser are options. Hormonal therapy, and other medical therapies to control bleeding, are also helpful in some people.

Liver AVMs are currently treated only if a person shows signs of liver or heart failure as a result of a liver VM. Decisions regarding treatment of liver VMs are made on a case-by-case basis and should be managed by a physician very familiar with the liver manifestations of HHT.

The recommended treatment for a telangiectasia or AVM depends on its size and location in the body.

Learn more about management of HHT in the International HHT Guidelines.

Frequently Asked Questions about HHT

Yes, but it is expensive, more complex than most genetic testing and generally helpful after HHT has first been confirmed in a family based on symptoms. In order to decide whether genetic testing will be helpful in your family, and if so who should be tested and in what order, it is usually necessary to be seen either at an HHT Center or a genetics clinic/department in your area.
The genetics of HHT works as follows: We each inherit two copies of each gene, one from our mother and one from our father. People with HHT have one functioning copy of the gene for HHT and one copy that is altered so that it does not function normally. Each time someone with HHT makes an egg or sperm, only one of these two genes will be included. It is completely random when each egg or sperm is formed as to whether the "altered"/HHT causing gene or the perfectly normal gene gets included. So, there is a 50% chance of passing on the altered copy with every pregnancy, but also a 50% chance to pass on only the normal gene.
No, but sometimes it can look like it did. At the genetic level, you either have HHT or you don’t. There is no such thing as being a carrier of HHT (that term is reserved for genetic disorders that are recessive, not dominant like HHT). If a grandparent and grandchild both have HHT, it can safely be assumed that the "parent" in between the two also has HHT. However, remember that HHT can be EXTREMELY variable in its severity even within the same family. For example, some people with HHT get multiple nosebleeds per day and some only a couple per year. So occasionally is might look like HHT skipped a generation because the "parent" had such mild manifestations of HHT that they were not obvious.
As long as the lung and brain malformations are treated, on average, the life expectancy of people with HHT is not significantly altered.
In the last decade much new information has been learned and published in medical journals about the treatment of AVMs in internal organs of individuals with HHT. Unfortunately, the majority of physicians aren’t yet familiar with the most current treatment options and recommendations. If you have been told you have a "spot", a nodule or AVM from an x-ray, CT scan or MRI, you and/or your local physician should immediately contact one of the HHT Treatment Centers. The medical professionals at the HHT Treatment Centers are glad to talk to patients and physicians from around the world about when and how an AVM should be treated.
Many do not, but they can. Our best information about this is from observation of lung AVMs. They have been known to increase in size over time. The growth is usually quite slow, but can occasionally be more rapid such as during puberty or pregnancy, or when combined with certain heart valve problems.
Not necessarily. About 30-50% of people with HHT will have at least one AVM in the lungs and about 5-20% will have an AVM in the brain. There doesn't seem to be a correlation between the severity of the nosebleeds and what's "inside" the body. Since there is no way to predict who will have an AVM of the lung or brain, routine screening for everyone with HHT –regardless of the severity of nosebleeds- is the only way to detect their presence.
We recommend that you call, or have your physician call, the nearest HHT multi-disciplinary treatment center, for recommendations about the most appropriate screening tests for your situation. Depending upon your insurance, history and preference, you can work with your family physician to get the screening done locally. Alternatively, the screening tests can be done at one of the HHT Clinics/Centers.
It’s often easier than you think. Each of these Centers has someone who helps with referrals, insurance authorization, logistics and scheduling. Since HHT is a rare disorder, there will never be expertise in all cities and medical centers. Most of the patients seen at the Treatment Centers have made arrangements to travel from out of state because they believe it is a valuable use of time and money. Often it is not necessary to have more than one visit to an HHT Center. The evaluation and screening can usually be done in one day. After the Center has seen you for evaluation and/or treatment, they are able to advise your local doctor about your long-term care needs. There is simply no substitute for being evaluated at least once in your life by physicians who specialize in your disorder.
Some people with HHT have abnormalities in the liver that can actually either cause or contribute to heart failure. The possibility of liver AVMs should be considered in a patient with HHT and high output heart failure, particularly if the heart failure occurs at a relatively young age. Currently, most of the treatments that have been successful in treating the telangiectasia and AVMs elsewhere in the body have proven dangerous when done on the liver. It is particularly important for someone with HHT not to have any treatments involving their liver without contacting an HHT Treatment Center first.
HHT is an "equal opportunity" disorder. It is not limited to, or found predominantly in, people of a particular ethnic background, as are some other genetic disorders. HHT has been found on every continent. The HHT Foundation has had requests for information from China, Greece, India, Japan, Peru, Russia, Norway, South Africa, to name just a few. Treatment centers have been formed in many countries.
Yes, as long as their hemoglobin or hematocrit is at an acceptable level.
There are currently no standard guidelines for the screening and treatment of lung AVMs in children. Based on the fact that some children have had complications from lung AVMs, we do advocate screening for all children of a parent with HHT. This screening should start as a baby with pulse oximetry every two or three years. Though oximetry will not detect mildly or moderately decreased oxygen levels, it will detect severely decreased oxygen levels. It seems to be the children who have severely decreased oxygen levels who are at risk for complications. Also, if a child is complaining of shortness of breath when exercising, or is having a hard time keeping up in sports, they should additional testing for lung AVMs depending on the age. At the age of 12, all children with HHT should have the same screening for lung AVMs recommended for adults. Children can be safely treated with embolization.
Unexplained anemia or low blood count, traces of blood in the stool, (although people with nosebleeds may also have blood in the stool), black (like tar) stool in the absence of iron therapy, and in extreme cases, eliminating or vomiting blood. But they rarely cause pain.
Yes. There are very few instances in which someone with HHT needs to limit their activity. Scuba diving is probably the one sport that individuals with HHT should avoid. Small lung AVMs may be present and cause "the bends".
Yes, as long as the pregnant woman has no untreated lung AVMs. We strongly recommend that all women known or suspected to have HHT be screened for lung and brain AVM prior to becoming pregnant, or during the early second trimester of pregnancy if a pregnancy is already in process. Serious complications- such as life threatening bleeding and strokes - have occurred in pregnant women with HHT who had undetected and thus untreated lung AVMs. Otherwise, serious HHT-related complications for the mother or baby are rare. Some women report that new skin telangiectases developed during their pregnancy and that their nosebleeds worsen. However, some women actually report an improvement in nosebleeds while pregnant.
Follow-up evaluation at an HHT Treatment Center at regular intervals is recommended. Small AVMs in the lung, which were too small to embolize originally, may reach a size where they need to be blocked off (embolized).
In the circulatory system, arteries take blood from the heart and distribute it to the tissues of the body via capillaries. Then the "used" blood is taken back to the heart via the veins. In HHT, some blood vessels are missing the capillaries, or the capillaries are a dilated and tangled jumble. This results in an artery and vein having a direct connection, which is not normal. These blood vessels that have missing or abnormal capillaries (telangiectases) can be fragile and rupture more easily than a normal blood vessel. Fortunately, most of the blood vessels in someone with HHT are perfectly normal.

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