Cavernous Malformations

Diagnosis

MRI scan of cavernous malformation

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Cavernous malformations generally are discovered during an MRI. This imaging may have been performed to investigate seizures, paralysis, numbness, vision changes or other neurological problems or as part of an evaluation for other diseases. Most commonly, cavernous malformations near the cortex are discovered while investigating the cause of seizures.

Some patients experience life-threatening hemorrhages from cavernous malformations, although these are uncommon. The risk of a hemorrhage is between 1 and 4 percent per year. Hemorrhages are the second most common way that a cavernous malformation is identified.

In rare instances, the condition is diagnosed after a patient experiences a gradual decline in function because of repeated small hemorrhages.

An MRI is the best technique for detecting cavernous malformations. These malformations usually have a very characteristic appearance that almost always leads to diagnosis. For detecting small cavernous malformations, however, it is important to have an MRI scan with a gradient echo sequence. This is a very sensitive type of MRI scan used to detect blood products. Small cavernous malformations may not be discovered if gradient echo sequences are not obtained.

Prenatal Screening

Genetic counseling and testing are available at Mayo Clinic and may be considered for people with more than one cavernous malformation or those with a family history of the condition. Prenatal testing to screen for the condition also is available for selected patients with familial cavernous malformations.