Cavernous malformations

What causes cavernous malformations?

The exact cause of a cavernous malformation is not well understood, though genetics may play a role.  In patients seen by physicians at Boston Children's Hospital, there was a strong family history in 25 percent of patients.  If multiple family members have seizure disorders or associated blood vessel abnormalities on the skin, other family members may be at higher risk of a cavernous malformation.  

The malformation results when small blood vessels (capillaries) within the brain mass or its coverings aggregate into enlarged or irregular masses. Compared to other blood vessels, capillaries have thin walls and lack supportive and stretchy tissue.  Thus, when they stretch out or malform from excessive blood flow, they often cannot return to their normal size.

Researchers have found some evidence that radiation treatments for leukemia and other brain tumors may lead to lesions similar to cavernous malformations. 

What are the symptoms of a cavernous malformation?

Symptoms are caused by an accumulation of blood in and around the cavernous malformation when it spontaneously bleeds. The bleeding from such a blood vessel malformation can be slow and intermittent (referred to as subacute) or it can be rapid, causing a sudden onset of symptoms.

Each child may experience symptoms differently, however, the following are some common symptoms that may be associated with a bleeding cavernous malformations:

• Gradual or rapid onset of a neurologic deficit of some type such as weakness or sensation changes in an arm or leg
• Seizures
• Headaches
• Irritability, or personality changes in personality

Children with multiple cavernous malformations in their brains usually lead normal active lives. It's not clear what makes a malformation bleed although head trauma may increase the risk. Thus, physicians recommend that children with cavernous malformations avoid activities with a high likelihood of severe head trauma, such as organized football. Otherwise, your child's activity does not need to be restricted.