DANDY-WALKER MALFORMATION

Dandy-Walker malformation (DWM) is a complex developmental abnormality of the posterior fossa visualized as a large posterior fossa (cyst), which communicates with the fourth ventricle. The size of the cyst and defect in the cerebellar vermis is variable.

ULTRASOUND – TRIAD OF FINDINGS:

• Retrocerebellar cyst (of variable size) communicating with a dilated 4th ventricle.
• Complete/partial agenesis of the cerebellar vermis.
• Enlarged posterior fossa with displacement of the tentorium, torcula and lateral sinus.
• Hydrocephalus, classically considered essential for the diagnosis of DWM may not be present at birth (develops in the first few months of life).

1. Classification

2. Associated Abnormalities

3. Ultrasound

4. Prognosis