IMPORTANT: We currently have a number of bugs related to image cropping and are actively trying to resolve them. In the meantime, we have disabled cropping. Apologies for any inconvenience. Stay informed: radiopaedia.org/chat

Dandy-Walker variant

Case contributed by Aditya Shetty
Diagnosis certain

Presentation

One episode of generalized tonic-clonic seizure; large head size.

Patient Data

Age: 2 years
Gender: Male
ct

A cystic area of CSF density is noted in the posterior fossa, with a "keyhole" appearance. 

This cystic area is in continuation with the fourth ventricle.

Vermian hypoplasia is also noted with gross hydrocephalus.

Annotated image

The "keyhole connection sign" (white dashes) refers to the abnormal connection of the cisterna magna and the posterior aspect of the fourth ventricle. 

Case Discussion

A case of Dandy-Walker variant (less severe type as part of the Dandy-Walker continuum) with gross hydrocephalus. A 'keyhole' appearance is formed due to vermian hypoplasia and the cystic area extending into the 4th ventricle

How to use cases

You can use Radiopaedia cases in a variety of ways to help you learn and teach.

Creating your own cases is easy.

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.