Dandy-Walker malformation
A congenital brain malformation characterized by hypoplasia of the cerebellar vermis and cystic enlargement of the fourth ventricle.
Full Definition
Dandy-Walker malformation is a complex congenital abnormality affecting the posterior fossa, characterized by complete or partial absence of the cerebellar vermis, cystic dilatation of the fourth ventricle, and enlarged posterior fossa with upward displacement of the tentorium and torcular herophili. Associated hydrocephalus is common, occurring in approximately 80% of cases. Prenatal ultrasound and fetal MRI can detect this condition, while postnatal imaging helps assess the degree of vermian hypoplasia and associated anomalies.
Usage
Usage note: Distinguish from other posterior fossa cystic lesions; specify the degree of vermian involvement.
In Context
- "Fetal MRI confirmed Dandy-Walker malformation with complete vermian agenesis and fourth ventricular cyst." — Prenatal diagnosis report