Presentation
Increased head circumference (?hydrocephalus).
Patient Data
MRI sequences demonstrate:
enlarged posterior pericerebellar space communicating with cystic dilatation of the 4th ventricle through vermian hypoplasia with a moderate anterolateral displacement of the cerebellar hemispheres.
dilated of the 3rd/lateral ventricles with patent cerebral aqueduct (of Sylvius)
dysgenesis of the corpus callosum.
extra-axial cysts of CSF signal in the middle cerebral fossae (arachnoid cysts)
Case Discussion
MRI features of a Dandy-Walker malformation with associated hydrocephalus, callosal dysgenesis, and arachnoid cysts of the middle cranial fossae type I according to the Galassi classification of middle cranial fossa arachnoid cysts.