Updated: Sep 4, 2023
“I See so much confusion between the terms ONH, SOD and De Morsier Syndrome so I wanted to post this from Children’s Hospital Las Angeles ONH research group… the label “SOD” is not accurate and is being abandoned by most medical professionals.” – Rachel Nawla 8/6/22
“We’ve posted this before, but here’s a good refresher on ONH vs. SOD:
We urge doctors and parents to abandon the term “septo-optic dysplasia” and use “optic nerve hypoplasia” instead. To understand why, we need a little history lesson:
The term SOD was coined by Georges de Morsier in the mid-20th century. He used the term to describe cases where patients were missing their septum pellucidum and also had some type of ophthalmological abnormality. Interestingly, de Morsier NEVER saw a case of optic nerve hypoplasia! He never intended the term SOD to be associated with small optic nerves.
Later in 1970, Dr. William Hoyt wrote a paper describing the association of ONH and hypopituitarism, but he mistakenly thought a missing septum pellucidum had something to do with it. Looking through the literature, he credited de Morsier with discovering the connection between ONH and a missing septum pellucidum – even though de Morsier never made this connection! Hoyt’s paper popularized the term “septo-optic dysplasia,” which doctors still use today.
Why is SOD wrong? Because the septum pellucidum has no importance. And what is the septum pellucidum anyways? It’s the very thin membrane separating the right and left ventricles in the brain, but it really has no purpose. It’s a little like the appendix; you don’t need it, and if it’s gone, it doesn’t cause any problems.
In recent years, the term SOD has been expanded to include other brain abnormalities. So some doctors will diagnose a child with SOD if they have small optic nerves and ANY other malformation of the brain. Lots of doctors interpret the diagnosis of SOD differently. The fact that the term SOD is so inconsistent and so “loosey-goosey” makes it really confusing, right?
Studies have shown that missing the septum pellucidum DOES NOT put kids at any greater risk for hormone problems. ALL CHILDREN WITH ONH ARE AT RISK FOR HORMONE PROBLEMS – NO MATTER WHAT BRAIN ABNORMALITIES THEY HAVE. Whether or not they have a normal or absent septum pellucidum, or any other brain abnormality, makes no difference. The practical lesson is: our kids need to be monitored for hormone problems no matter what their MRI shows.
The term SOD puts too much importance on the septum pellucidum, which we know has no significance. The term ONH may not be perfect, but it is more clear. It means your child has small optic nerves and is at risk for hormone, developmental and neurological problems.”This is how it was classified.
In order to have SOD- you needed two of the three
- Optic nerve hypoplasia
- Endocrine dysfunction
- Absence of the septum pellucidum
Many children with ONH were not being tested for endocrine issues and as we know that can be fatal. Dr. Borchert would like us and the medical community to use the following:
- ONH
- ONH with endocrine dysfunction
- ONH with brain abnormalities
- ONH with endocrine dysfunction and brain abnormalities