Presentation
Headache
Patient Data
The dilated fourth ventricle is seen freely communicating with infracerebellar posterior fossa cyst. The cerebellar vermis is upward displaced with no hypoplasia. Preserved T2 hypointense signal void flow at aqueduct showing normal bidirectional flow. Normal bidirectional flow of CSF at the craniocervical junction and cervical subarachnoid spaces is detected.
These findings are compatible with Blake's pouch cyst.
Case Discussion
Tetraventricular moderate arrested "compensated" hydrocephalus, with hyperdynamic CSF flow across patent aqueduct and suggested persistent Blake's pouch cyst.
Blake's pouch cyst is a posterior fossa developmental cyst that represents posterior ballooning of inferior medullary velum into cisterna magna, below and posterior to the vermis. It communicates with an open 4th ventricle.
Unable to process the form. Check for errors and try again.