Angioma Alliance

The best information I have found on Cavernous Angiomas is the website Angioma Alliance. This site contains a wealth of information on the disease, and also has links to helpful resources for the newly diagnosed patient.

The following is copied directly from the AngiomaAlliance.org

About Cavernous Angioma

Cavernous angiomas are vascular lesions comprised of clusters of abnormally dilated blood vessels.  These lesions can be found in the brain, spinal cord, and, rarely, in other areas of the body including the skin and retina. Multiple names refer to this condition:

• cavernous angioma 
• cavernous hemangioma 
• cerebral cavernous malformation (CCM) 
• cavernoma

Cavernous angiomas are typically described as having a raspberry-like appearance due to their composition of multiple bubble-like structures called caverns.   Each cavern is filled with blood and lined by a specialized cell layer called the endothelium.  Endothelial cells are the basic building blocks that work in conjunction with other cell types to form blood vessels.  In the case of cavernous angioma, the bubble-like caverns are grossly dilated vessels that leak due to defects in the endothelial cells and due to the loss of other structural components that are required for normal vessel walls.  Patients may present with a single or multiple cavernous angioma lesions.  Lesion size is variable, ranging from microscopic to a few inches in diameter and the lesions may cause a wide variety of symptoms including seizures, stroke symptoms, hemorrhages, and headaches.

Incidence

Cavernous angiomas are estimated to occur in approximately one out of every 500-600 people, that is approximately 0.2% of the general population.  While presentation of cavernous angioma is not uncommon in children, individuals often show the first sign of symptoms in their 20’s or 30’s.  Cavernous angiomas can continue to form later in life; therefore incidence rates and number of angiomas per person are higher among adults.  Generally, more than 30% of those with cavernous angioma eventually will develop symptoms.

Familial Cavernous Angioma

For at least 20% of those with the illness, cavernous angioma is hereditary. This form of the illness is often associated with multiple cavernous angiomas.  While familial cavernous angioma can happen in any family, it occurs at a higher rate among Hispanic-American families who trace their heritage to New Mexico.  This prevalence in Southwestern Hispanic-American families is due to a specific genetic mutation which has been passed through as many as 17 generations within this cultural group. 

Each child of someone with the familial form has a 50% chance of inheriting the illness.  Recent research has shown that there are at least three genes that cause the familial form of cavernous angioma; inheritance of a causative mutation or deletion in any one of these genes can lead to the illness.

Sporadic Cavernous Angioma

In addition to the familial form, cavernous angioma may arise sporadically.  Under this condition, there is no associated inherited genetic mutation.  The sporadic form typically presents as a solitary cavernous angioma that may be present at birth or may develop later in life.  Because sporadic lesions do not arise following the same genetic inheritance as with familial cases, related family members will not have a predisposition for the condition.  Additionally, children of those with sporadic cavernous angioma may have no greater chance of having cavernous angioma than anyone else in the general public (one out of 500-600 individuals).

Associated Venous Angioma

Up to 40% of solitary cavernous angiomas may develop in the vicinity of another vascular anomaly called a venous angioma. The venous angioma, also known as venous malformation or developmental venous anomaly, usually does not create problems unless it is associated with a cavernous angioma. It may make surgery more difficult; the goal is not to disturb the venous angioma while removing the cavernous angioma.In some people, a venous angioma may lead to the development of more than one cavernous angioma.

Other Vascular Malformations

The cavernous angioma is part of a spectrum of lesions known as "angiographically occult vascular malformations" related to the fact that they are not visible on an angiogram. Cavernous angiomas can not be seen on angiogram because they are low-flow anomalies in which blood flows through the lesion slowly. This is one quality that makes cavernous angiomas different from arteriovenous malformations which are high blood flow lesions that are readily visible on angiogram.

Symptoms  

Cavernous angioma symptoms are highly variable among individuals; in some cases no symptoms may be present.  However, when symptoms do manifest they often depend on the location of the angioma and on the strength of the angioma walls and their propensity for bleeding.  Cavernous angiomas can cause seizures.  A person who suffers from seizures is said to have epilepsy. There are many types of seizure including mild absence seizures and dramatic tonic-clonic seizures.  Seizures tend to worsen with age and frequency. Most cases of epilepsy can be well controlled with medications.  The type of seizure a person experiences depends, in part, on the location of the cavernous angioma. If a person has seizures and more than one cavernous angioma, it may be difficult to pinpoint which cavernous angioma is the cause of the seizures.

In addition to seizures, cavernous angiomas can cause neurological deficits such as weaknesses in arms or legs, vision problems, balance problems, and/or memory and attention problems. As with seizure, the type of deficit is associated with which part of the brain or spinal cord the cavernous angioma is located. Symptoms may come and go as the cavernous angioma changes in size with bleeding and reabsorption of blood.

Cavernous angiomas can bleed in a number of different ways:

• Angiomas can bleed slowly within the walls of the angioma and remain quite small.  A small hemorrhage may not require surgery and may be reabsorbed by the body.  However, continued small hemorrhages in the same cavernous angioma often cause deterioration in function.
• Angiomas can bleed more profusely within the walls of the angioma. This can cause them to increase in size and to put pressure on the surrounding brain tissue.
• Finally, angiomas may bleed through a weak spot in the angioma wall into the surrounding brain tissue. This is called an overt hemorrhage.

The risk of hemorrhage is dependent on the number of angiomas.  The higher the number, the greater the chance of one or more hemorrhages occurring sometime over a lifetime.  On average, cavernous angiomas that have bled in the past are those that are the most likely to bleed again, particularly in the first two years after their initial bleed.  It is also important to note that a hemorrhage in a cavernous angioma in the brain stem can be life-threatening, as the brainstem is responsible for regulating critical life processes including breathing and heartbeat.

Finally, those with cavernous angioma may experience headache. This seems to be true particularly when a lesion has undergone recent bleed activity.

Cavernous Angioma Statistics

1. 1 in 500-600 people have at least one cavernous angioma.
2. At least 30% of those with a cavernous angioma eventually will develop symptoms.
3. At least 20% of those with cavernous angioma have the familial form of the illness.
4. Up to 40% of solitary cavernous angiomas may have an associated venous angioma.
5. Age at first diagnosis:

Under 20: 25-30%

Age 20-40: 60%

Over 40: 10-15%

1. Primary symptom:

• Seizure – 30%
• Neurological deficit – 25%
• Hemorrhage – 15%
• Headache – 5%

1. Odds of your child having cavernous angioma:

• If you have sporadic cavernous angioma, your child is at no greater risk for developing a cavernous angioma than anyone in the general population; that is a one in 500 chance (0.2%).
• If you have familial cavernous angioma, your child may have a 1 in 2 chance (50%) of inheriting the causative gene change and developing cavernous angioma. 

Diagnosis and Treatment

Cavernous angiomas are diagnosed most often when they become symptomatic. Although cavernous angiomas have been known since the 1930’s, they have not been reliably diagnosed until the advent of the MRI (magnetic resonance imaging) in the 1980’s. Previously, the illness may have been misdiagnosed as multiple sclerosis or as a seizure disorder with no known cause. Cavernous angiomas are not visible on angiogram and were only inconsistently visible on CAT scans. An MRI scan, with and without contrast and with gradient echo sequences or susceptibility weighted imaging, read by an experienced physician remains the best means of diagnosing this illness. The MRI scan may need to be repeated to assess change in the size of a cavernous angioma, recent bleeding, or the appearance of new lesions.

Most cavernous angiomas are observed for change in appearance, recent hemorrhage or clinical symptoms. Medications are available to treat seizures and headaches caused by cavernous angiomas. Surgery is advocated for cavernous angiomas with recent hemorrhage, those which are expanding in size, and in some cases, those which are causing seizures. Radiosurgery, by gamma knife, linear accelerator or new shaped beam techniques, is a controversial treatment that has been used on cavernous angiomas too dangerous to reach through traditional surgery.

For familial cases of cavernous angioma, genetic testing is another option for diagnosis.

Surgery

Cerebral cavernous angiomas are surgically removed (resected) using a craniotomy, or opening the skull. This is usually performed under general anesthesia, except in cases where mapping of the brain while awake is needed. Cavernous angiomas in the spine are removed using laminectomy or unroofing of the vertebrae.

Surgery for cavernous angioma has been made safer using the operating microscope (microsurgery) and image guided surgical navigation (also known as computer-assisted or frameless stereotaxy) to reach the cavernous angioma with as little disruption to normal brain or spinal cord as possible.

Risks of any surgery, including cavernous angioma, include stroke, paralysis, coma or death, although these complications are rare with modern surgery performed by expert neurosurgeons. Surgery on cavernous angioma in the brain stem and spinal cord is more risky, but these cavernous angiomas are more dangerous if left alone. While recovery is different for everyone, many patients leave the hospital within a few days and resume normal life within a few weeks of surgery. However, people with neurological deficits may require a prolonged period of rehabilitation.

What We Don't Know about Cavernous Angioma

While researchers continue to make discoveries about cavernous angioma every day, many important research questions remain.

• Genetic researchers and a growing number of other researchers are working to determine the cause of the illness and the mechanisms by which the defective blood vessels are formed.
  
   
• We don't know most of the factors that lead to angioma bleeding and re-bleeding. Efforts to uncover what causes a particular cavernous angioma to bleed will help us to be able to reduce the risk of bleeding.
  
   
• We don't know how to remove a cavernous angioma without brain surgery or how to prevent them from becoming symptomatic. Less intrusive treatment methods may allow for control of more angiomas before they become problematic.