Isolated (Non-Syndromic) Craniosynostosis
Craniosynostosis can occur at any of the sutures in the skull. The six major skull sutures affected are the metopic, the two coronal sutures, the sagittal suture, and the two lambdoid sutures. The most common kind of craniosynostosis is when only one suture closes. It is called non-syndromic (sin-DRŌ-mic) craniosynostosis, or isolated craniosynostosis. These babies usually do not have other health problems at birth.
A different and rare form is caused by one or more sutures closing too soon. Also, these babies are born with other medical problems. This is called syndromic craniosynostosis.
We treat syndromic craniosynostosis very differently from non-syndromic craniosynostosis. We discuss the care of patients with syndromic craniosynostosis in detail here.
Isolated craniosynostosis occurs in about one in 2,500 births. The most common type is closure of the sagittal suture. This makes up about half of all cases.The metopic suture is the only cranial suture that normally closes before adulthood. It usually closes at about 8 months of age. All remaining sutures should remain open until adulthood, long after the brain has stopped growing.
The two biggest concerns related to craniosynostosis are:
- The risk of increased pressure on the brain
- Emotional or psychological effects of skull deformity
Very high pressure in the skull can cause learning delays and blindness. There is a 15% risk for increased pressure developing in the skull when a single suture is closed.
When to treat isolated craniosynostosis
Some kind of surgery is needed to treat isolated craniosynostosis. Most patients with single suture craniosynostosis do not develop increased pressure on the brain in the first year of life. There are few urgent reasons to operate during the first year of life. However, the timing and scope of the surgery depend on:
- What suture or sutures are closed
- The age at diagnosis
- How badly misshapen the skull has become
For reshaping the skull, it is best to perform surgery before 1 year of age. This is best because:
- The skull bones are softer in infants younger than 1 year of age. This allows for easier and more effective shaping.
- The gaps in the bone that are created from making the skull bigger will heal along with new bone if performed at younger than 1 year of age.
- There is evidence that performing surgery before one year of age protects the brain
The goal of treatment is to balance the remaining growth at the open sutures with the lack of growth at the closed suture(s) to achieve as normal a head shape as possible. This usually requires an overcorrection of the headshape that the patient grows into over time.
What else determines care for isolated craniosynostosis?
The types of surgery we use depend on what suture is closed. (For more information about specific concerns related to types of sutures closed, please see “Craniosynostosis–Suture Specific Concerns”) Early diagnosis of elevated pressure inside the skull can prevent partial or total blindness and learning delays. This makes the diagnosis and prevention of elevated pressure in the skull our priority as we treat patients with craniosynostosis.
A team of many experts will examine your child to determine what treatment we will recommend. Each patient is seen by a plastic surgeon who specializes in reconstruction of the skull and face (craniofacial), pediatric brain surgeon (neurosurgeon) and a pediatric eye doctor (ophthalmologist).
We use head imaging scans such as CT and MRI, to view a baby’s skull to create a surgical plan. We also examine a baby’s eyes to watch for signs of pressure on the brain and eye problems.
We also can directly monitor the pressure inside the skull. This remains the most reliable tool for measuring the pressure, but it requires admission to the hospital. It also requires us to place a device inside the patient’s skull. So, we use this only for patients we suspect have increased pressure but are not sure that surgery is indicated, which is rare. Unfortunately, there are no reliable ways to use scans (radiology) to find increased pressure on the brain. A yearly eye exam is given to patients without symptoms of pressure. This tests looks for bulging of the optic disc at the back of the eye, which may be present if there is increased pressure inside the skull.