Dandy-Walker syndrome

Dandy-Walker Syndrome is a rare congenital abnormality in which there is usually an absence of the foramina of Magendie and Luschka.

It is characterised by:

• cystic dilatation of the fourth ventricle due usually to absence of the foramina
• dilatation of the third and lateral ventricles - but to a lesser extent than the fourth
• enlargement of the posterior fossa with a high tentorium cerebelli and transverse sinuses
• wide separation of the cerebellar hemispheres with a small vermis, displaced laterally
• various other developmental abnormalities in 65% of patients