Septooptic Dysplasia

KEY FACTS

TERMINOLOGY

• Septooptic dysplasia (SOD)

• De Morsier syndrome

IMAGING

• Absent septum pellucidum, small optic chiasm

• Optic nerves, pituitary gland, septum pellucidum

• Coronal imaging shows

○ Flat-roofed ventricles

○ Downward-pointing anterior horns

• 3 orthogonal planes crucial to identify all findings

○ Absent septum pellucidum, flat roof of frontal horns,

small optic chiasm

CLINICAL ISSUES

• Newborns: Hypoglycemic seizures, apnea, cyanosis,

hypotonia, prolonged conjugated jaundice, and (in boys)

microphallus

• Abnormal endocrine function (60%): Look for multiple

pituitary deficiencies

• Normal endocrine function (40%): Often have

schizencephaly, seizures

• Child with short stature, endocrine dysfunction

• Normal or color blindness, visual loss, nystagmus,

strabismus

• ± mental retardation, spasticity, microcephaly, anosmia

• 75-90% have brain abnormalities; 45% have pituitary

insufficiency

• Bilateral optic nerve hypoplasia (70%)

DIAGNOSTIC CHECKLIST

• SOD in small-stature pediatric patient with absent septum

pellucidum

• Small optic nerves, with ectopic posterior pituitary lobe,

with absent septum pellucidum

(Left) Coronal graphic depicts

flat-roofed anterior horns and

the absence of a midline

septum pellucidum. The

anterior horns are draped

inferiorly around the fornices

﬊, and the optic chiasm ſt is

small. (Right) Funduscopic

photograph in a patient with

absent septum pellucidum,

bilateral optic nerve

hypoplasia, and ectopic

posterior pituitary gland

shows a hypoplastic optic disc

﬈.

(Left) Coronal T2WI FSE MR

shows the absence of septum

pellucidum and pointing ﬈ of

the inferior margins of the

frontal horns draped over

fornices. Note that the optic

chiasm ﬊ is normal in size, as

is often the case in septooptic

dysplasia. (Right) Coronal

T2WI FSE MR in the same

patient at the level of the

intraorbital optic nerves shows

unilateral optic nerve

hypoplasia. The right optic

nerve ﬈ is tiny, running

through a small optic nerve

sheath. The left optic nerve ﬉

is normal.

Brain: Pathology-Based Diagnoses: Malformations,

Trauma, and Stroke

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