Craniosynostosis is quite a rare condition that affects how the bones in the skull grow. ‘Cranio’ means head; ‘synostosis’ means fusion. There are different types of craniosynostosis. They all affect the shape of the head.
In most cases it’s just head shape that’s affected. But in complex cases the bones in the face – and sometimes hands and feet – are also affected and fuse together too early.
What is craniosynostosis?
At birth, a baby‘s skull is made up of bony ‘plates’ separated by ‘seams’ or ‘sutures’ similar to those in clothing.
The sutures are there to help with moulding of the head during delivery, and play a role in shaping the head as it grows. The sutures eventually fuse, forming a protective ‘helmet’ for the brain – the skull.
But with craniosynostosis, a single suture or a number of sutures fuse much earlier than they are supposed to – even weeks or months before a baby is born.
This can restrict the growth and development of the brain, as well as the shape of the head.
What causes craniosynostosis?
For children with a single suture synostosis the cause is currently unknown.
When craniosynostosis affects multiple sutures, it is often associated with a particular syndrome.
There are in fact a number of genetic conditions linked with craniosynostosis. These include:
Muenke (P250A) syndrome
All of these conditions are the result of a problem with a particular gene. This affected gene is passed from parent to child.
What are the signs and symptoms of craniosynostosis?
For children with single suture synostosis, one suture in the skull is affected. This can be called either saiggtal, metopic or unicoronal synostosis. Rarely but occasionally there is a single suture called lambdoid synostosis which can also be fused. The fusion of a particular single suture gives rise to an unusual headshape. For example a sagittal synostosis affects the suture that runs across the top of the head and gives rise to a “rugby ball” shaped-head.
It is usually an aesthetic operation to have it corrected. Some children with sagittal synostosis can have problems with speech and language delay and there is a possible increased incidence of raised intracranial pressure. Whether you have surgery or not does not change these potential issues.
More complex forms of craniosynostosis are ususally be associated with other problems.
For example, if the bones of the upper jaw don’t grow forwards normally, this can affect a child’s breathing. Also if the bones above and below the eye sockets don’t grow properly, the eyes are exposed and this can affect how they open and close, and will mean that they are not adequately protected.
Another possible complication is raised pressure inside the head. This is called raised intracranial pressure (ICP). It can happen because the bones of the skull can’t expand enough for the growing brain. Or because the breathing is very obstructed and noisy.
Some people also have an obstruction in the flow of their ‘brain water’, called cerebrospinal fluid (CSF), which normally circulates throughout the brain.
Any obstruction can lead to a build-up of CSF – a condition called hydrocephalus.
Finally, raised ICP can be due to congestion of the blood vessels within the head.
How is craniosynostosis diagnosed?
Someone with craniosynostosis will be referred to their nearest specialist team; there are four across the UK.
The team will do a number of tests including X-rays and CT scans. They will assess if there are any problems that need immediate attention – for instance, raised intracranial pressure or difficulty breathing.
How is craniosynostosis treated?
If a patient doesn’t need any early intervention, the specialist team keeps an eye on them over time.
For people who have just one suture fused, decisions about surgery are made on cosmetic grounds. The timing of surgery varies from patient to patient, and depends on the exact nature of their condition.
For complex cases, surgery is carried out as and when needed to help with any of the problems that have been discussed.
It’s often best to leave it until later in childhood when facial growth is slowing down – the earlier surgery is carried out, the more likely it is that some or all of it may need to be repeated. But this is not always possible due to problems inside the head or with the eyes or jaw.
Also children who look different may be bullied at school, so there are often good reasons for operating earlier.
This is discussed carefully with every family, to decide when the best time for surgery might be.
What happens next?
The majority of people born with single suture fusion will, after surgery, have a natural looking head shape.
In most cases the condition does not affect brain development in any way. They can progress at school to the best of their ability, and can look forward to a healthy future.
It may be a little different for people with complex craniosynostosis. The condition is more severe and, even with surgery, facial appearance is not always exactly like everyone else.
The condition can affect how some people learn and they may grow up with different learning abilities.
It’s possible that a person with the condition may have problems with bullying or self-esteem.
There are people to talk to like psychologists and nurse specialists who will help and can offer suggestions of how to cope.
They can also liaise with schools and talk to teachers about any bullying or teasing issues.