Go Back Brain/18. More than one of above/Normal, Technique, Anomaly/18.1 - Septo-optic dysplasia/ Go to Index

Described by deMorsier in 1956

Consists of optic nerve hypoplasia and deficiency of the septum pellucidum

Considered as mildest form in the spectrum of holoprosencephaly.

Septum pellucidum

Absent 64%

Partially absent 36%

Usually anterior portion remains

Additional findings/associations:

Agenesis of corpus callosum

White matter hypoplasia with ventriculomegaly

Gray matter heterotopia

Olfactory agenesis/hypoplasia.

Clinical findings:

Visual symptoms ranging from normal vision to nystagmus and blindness

Hypothalamic-pituitary dysfunction

Growth retardation secondary to insufficient growth hormone and TSH

Seizures (50%).

Schizencephaly in 50% of patients

When schizencephaly present:

More likely to have normal-sized ventricles

Portions of septum pellucidum spared.

When schizencephaly absent:

White matter hypoplasia with ventriculomegaly more likely

Complete absence of septum pellucidum

Worse hypothalamic-pituitary dysfunction.