Craniosynostosis – Symptoms and Causes
Overview
Craniosynostosis occurs when a baby’s skull bones close too early. These bones normally stay flexible as an infant’s brain grows. When they fuse prematurely, the skull cannot expand properly, causing the head to develop an unusual shape.
The skull has several soft spots (fontanels) where sutures meet. The largest is on top of the head behind the forehead (anterior fontanel), with another significant one at the back (posterior fontanel).
Smaller fontanels appear on each side of the skull.
Types of craniosynostosis include:
- Single suture (most common)
- Multiple suture (affecting more than one joint)
- Syndromic (linked to genetic disorders)
Without intervention, severe cases may lead to:
- Increased pressure inside the skull
- Potential brain development issues
- Visible facial and head asymmetry
Signs of Abnormal Skull Growth
Babies born with fused skull joints show certain signs. The shape of the baby’s head often looks unusual at birth or within the first few months.
How severe these signs are depends on how many joints have fused and when this happened during brain growth. Signs include an oddly shaped skull and hard ridges you can feel along the fused joints.
Several types of fused skull joints exist. Most cases involve just one joint, but complex cases can affect multiple joints. When multiple joints fuse and relate to genetic conditions, doctors call this syndromic craniosynostosis.
The types are named based on which joints are affected:
Sagittal Fusion: Most common type where the joint running from front to back at the top of the head fuses. This makes the head grow long and narrow, called scaphocephaly.
Coronal Fusion: When one side joint (running from ear to skull top) fuses, the forehead flattens on that side and bulges on the other. The nose turns and the eye socket on the affected side rises. If both sides fuse, the head looks short and wide with the forehead tilted forward.
Metopic Fusion: When the joint running from the nose bridge up the middle of the forehead fuses, it creates a triangular forehead and a wider back of the head (trigonocephaly).
Lambdoid Fusion: This rare type affects the joint at the back of the head. It can make one side of the baby’s head appear flat, cause uneven ear heights, and tilt the head to one side.
Other Causes of Head Shape Changes
Not all unusual head shapes mean fused skull joints. For example, if your baby’s head looks flat on one side, it might simply be from lying too much on that side. This can be fixed by:
- Changing your baby’s position regularly
- Using special helmet therapy if needed
When To Contact Your Doctor
Doctors will check your baby’s head growth during regular checkups. You should talk to your doctor if you notice:
- Unusual head shape
- Hard ridges on your baby’s skull
- One side of the head looking flatter than the other
- Uneven ear placement
- Forehead bulging
Early detection is important because treatment works best when started early. Your doctor can determine if the head shape is normal or if further testing is needed.
Causes
The exact cause of craniosynostosis often remains unknown. Doctors classify this condition into two main types:
- Nonsyndromic craniosynostosis is the most common form. While doctors haven’t identified a specific cause, they believe it results from a mix of genetic factors and environmental influences during development.
-
Syndromic craniosynostosis stems from specific genetic conditions. These include:
- Apert Syndrome
- Pfeiffer Syndrome
- Crouzon Syndrome
These genetic syndromes affect skull formation and typically cause additional physical features and health issues beyond the skull abnormalities.
Risks Without Treatment
Untreated craniosynostosis can lead to several serious problems. The head and face may remain permanently misshapen, which can affect a child’s self-esteem and social interactions with others.
When surgical correction isn’t performed, some children face increased pressure inside the skull. Children with syndromes related to craniosynostosis face a higher risk of increased skull pressure than those with simple cases.
Untreated increased skull pressure can lead to various consequences, such as learning and development delays, reduced cognitive abilities, vision loss, seizure disorders, and persistent headaches.
Children with syndromic craniosynostosis need careful monitoring. This is because their skulls may not expand properly to accommodate brain growth.
