What is Sagittal Craniosynostosis?
In our previous post, we explained the difference between craniosynostosis and deformational plagiocephaly. There are four major sutures of the human skull – sagittal, metopic, coronal (paired), and lambdoid (paired). The sagittal suture runs down the middle of the skull dividing it into the right and left sides. This suture normally fuses in a person’s 20’s.
When this suture fuses early, it restricts growth of the skull out to the sides causing a characteristic long narrow head shape with frontal bossing.
Why does Sagittal Craniosynostosis need to be treated?
In the first year of life, a baby’s brain grows very rapidly and the skull bones are very thin and moldable. When the sagittal suture fuses too early, there is a restriction of growth of the skull out to the sides however the brain continues to grow in the front and back resulting in a long narrow head shape.
As the child gets older, the skull bones become harder and less moldable; however the brain still continues to grow until around 8 years old. If the skull bones can not accommodate the growing brain, then this causes abnormal pressure on the brain. This can manifest as developmental delays, headaches, behavioral problems, and visual problems. A brain MRI on a patient with sagittal craniosynostosis demonstrates sulcal effacement and narrowing of the ventricles, which means the space inside the skull is too tight for the brain.
An MRI of the same patient after cranial vault remodeling shows improvement of ventricular narrowing and sulcal effacement.
The goal of early (before 12 months of age) surgical treatment of sagittal craniosynostosis is to allow the brain to grow without restriction in order to avoid problems with development, behavior, and vision in the future.