Dysgenesis of the corpus callosum, can be of varying extents from pure agenesis as in this case.
Classical features demonstrated;
- racing car appearance of ventricles
- viking's helmet/moosehead appearance of ventricles
- widely spaced lateral ventricles
- high riding 3rd ventricle
In addition a common associated of hippocampal atrophy, with very lateral temporal horns of the lateral ventricle as a result of this. These measure 22 mm versus a normal of 2 mm.