Brain cystic malformations

**Definition:** A disease caused by expansion of the roof plate of the brain vesicle, or by extraaxial structures such as an arachnoid membrane or migrating ependymal cells. This disease is characterised by the presence of fluid filled cysts in the brain. This disease may present with asymmetry of the skull, brain compression, raised intracranial pressure, hydrocephalus, bleeding or seizures. This disease may also be asymptomatic. Confirmation is through observation of intracerebral cysts by imaging.

**Exclusions:** - Dandy-Walker malformation with hydrocephalus - Acquired porencephalic cysts - Dandy-Walker malformation without hydrocephalus