Dandy-Walker variant

Case contributed by Dr Mohammad A. ElBeialy

Diagnosis almost certain

Presentation

Large head size with convulsions. Prenatal U/S shows hydrocephalus.

Patient Data

Age: 1 month

Gender: Female

From the case: Dandy-Walker variant

Axial non-contrast

moderate supratentorial dilatation of the ventricular system. The bodies of the lateral ventricles are widely separated and parallel with high-riding 3rd ventricle.
mega cisterna magna with retro-cerebellar cystic lesion of CSF density communicating with the 4th ventricle.
hypoplasia of the cerebellar vermis.
no mass lesion or parenchymal area of abnormal attenuation.
normal cortical sulci.
no extra-axial collection.

Diagnosis:
Dandy-Walker variant with moderate supratentorial hydrocephalus and mega cisterna magna as well as retro-cerebellar cyst communicating with the 4th ventricle through hypoplastic vermis. Associated agenesis of the corpus callosum.

Case Discussion

Dandy-Walker variant is associated with variable degrees of vermian hypoplasia. A retrocerebellar cyst is seen communicating with the 4th ventricle with supratentorial hydrocephalus. Association with agenesis of the corpus callosum is common. DW variant is more common than DW malformation.