Septo-optic dysplasia (SOD) is a condition characterised by optic nerve hypoplasia and absence of septum pellucidum and, in two thirds of patients hypothalamic-pituitary dysfunction. It is best thought of as being part of the holoprosencephaly spectrum (see classification system for midline malformations).
Septo-optic dysplasia has an estimated prevalence of ~ 1:50,000. There is no recognised gender predilection.
A number of risk factors have being identified, including 8:
- maternal diabetes
- quinidine ingestion
- illicit drugs
- cytomegalovirus infection
Clinical presentation of septo-optic dysplasia is varied, and largely dependent of whether or not it is associated with schizencephaly (~ 50% of cases). This association is used to define two forms of the condition 1,8:
- not associated with schizencephaly
- visual apparatus more severely affected
- hypothalamic-pituitary dysfunction present in 60-80% of patients 6,8
- may present as hypoglycaemia in the neonatal period 6
- ectopic posterior pituitary may be present
- olfactory bulbs may be absent (Kallmann syndrome) 8
- associated wtih schizencephaly
- optic apparatus less severely affected
- may be etiologically different 8
- sometimes referred to as septo-optic dysplasia plus 8
In addition, a number of other associations are recognised including:
All imaging modalities which can visualise the septum pellucidum (ultrasound, CT and MRI) will detect its absence in septo-optic dysplasia. Some additional modality dependent features may also be visible.
In addition to enlarged lateral ventricles with an absent septum pellucidum, CT may demonstrate small optic apparatus (best seen with volumetric scanning and coronal reformats) and associated small bony optic foramina.
MRI is the modality of choice for assessing septo-optic dysplasia.
- may show a "point down" appearance of the lateral ventricular frontal horns on coronal images
- absent septum pellucidum
- hypoplastic pituitary stalk
- hypoplastic optic chiasm/optic nerves and globes
History and etymology
Septo-optic dysplasia was first described by George de Morsier (1894-1982), Swiss neurologist in 1956 6, 7.
- 1. Sener RN. Septo-optic dysplasia associated with cerebral cortical dysplasia (cortico-septo-optic dysplasia). J Neuroradiol. 1996;23 (4): 245-7. - Pubmed citation
- 2. Tien RD, Felsberg GJ, Krishnan R et-al. MR imaging of diseases of the limbic system. AJR Am J Roentgenol. 1994;163 (3): 657-65. AJR Am J Roentgenol (citation) - Pubmed citation
- 3. Barkovich AJ, Fram EK, Norman D. Septo-optic dysplasia: MR imaging. Radiology. 1989;171 (1): 189-92. Radiology (abstract) - Pubmed citation
- 4. Levine LM, Bhatti MT, Mancuso AA. Septo-optic dysplasia with olfactory tract and bulb hypoplasia. J AAPOS. 2001;5 (6): 398-9. doi:10.1067/mpa.2001.118869 - Pubmed citation
- 5. Osborn RE. Schizencephaly and septo-optic dysplasia: separate entities. Pediatr Radiol. 1989;20 (1-2): 137. - Pubmed citation
- 6. Sarnat HB. Malformations of the nervous system. Elsevier Science Health Science div. (2008) ISBN:0444518967. Read it at Google Books - Find it at Amazon
- 7. from whonamedit.com, the dictionary of medical eponyms.
- 8. Castillo M. Neuroradiology companion, methods, guidelines, and imaging fundamentals. Lippincott Williams & Wilkins. (2006) ISBN:0781779499. Read it at Google Books - Find it at Amazon
Synonyms & Alternative Spellings
|Synonyms or Alternative Spelling||Include in Listings?|
|De Morsier disease||✗|
|De Morsier's disease||✗|
|Septooptic dysplasia (SOD)||✗|
|De Morsier syndrome||✓|