Cerebral cavernous malformations are usually diagnosed by computerized axial tomography (CAT) scan or, more accurately, a magnetic resonance imaging (MRI) scan with gradient echo sequencing.

Most familial cerebral cavernous malformations are present at birth (congenital). They are thought to arise between three and eight weeks of gestation, although the exact mechanism of CCM formation is not understood.

Symptoms include seizures , dizziness , stroke, vomiting, uncontrollable hiccups, periodic weakness, irritability and/or changes in personality, headaches , difficulty speaking, vision problems or, rarely, brain hemorrhage.

Cavernous malformations occur in people of all races and both sexes. The male-female ratio is about equal. Family history may be predictive, especially in patients of Hispanic descent.

Vascular malformations can potentially occur many years after radiation therapy to the brain. Additionally, it is also assumed that severe or repeated head trauma can cause cerebral capillaries to bleed.