What broader group of conditions is septo-optic dysplasia related to, and which of these is the closest differential diagnosis?
Holoprosencephaly spectrum ranges from septo-optic dysplasia to alobar holoprosencephaly. Lobar holoprosencephaly is the closest differential.
What features are helpful in distinguishing lobar holoprosencephaly from septo-optic dysplasia?
An important finding in helping distinguish septo-optic dysplasia from lobar holoprosencephaly is unfused fornices in the former.
Selected images from the MRI of a child demonstrates absence of the septum pellucidum and an optic chiasm that is markedly reduced in size. Also note the azygous anterior cerebral artery.