Presentation
One episode of generalized tonic-clonic seizure; large head size.
Patient Data
Age: 2 years
Gender: Male
From the case:
Dandy-Walker variant
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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.
From the case:
Dandy-Walker variant
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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