Case contributed by Assoc Prof Frank Gaillard


Developmental delay.

Patient Data

Age: Child

MRI brain


MRI of the posterior fossa demonstrates absence of the cerebellar vermis with complete fusion of the cerebellar hemispheres across the midline. Characteristic transverse folia inferiorly can be clearly seen crossing the midline. The fourth ventricle is abnormal in shape, elongated in the AP direction. Features are consistent with rhomboencephalosynapsis.

Additionally the corpus callosum is dysplastic and there is fusion of the cerebral hemispheres across the midline consistent with coexisting syntelencephaly. 

Case Discussion

This is a very unusual case comprising two rare abnormalities: rhomboencephalosynapsis and syntelecephaly, not known to be associated. It does however highlight the need to carefully examine the whole brain when one abnormality is found as others are often present. 

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.