Craniosynostosis: Definition, Types, Causes, Symptoms, Diagnosis, Treatment and Overview

When you look at a skull it looks like a solid piece, but in reality, it is several bones that are attached to each other.

The skull of a newborn is made up of seven main plates of bone.

In baby skulls, these bones have not yet come together. Instead, they are connected by fibrous tissue called the suture, which are the narrow spaces between the plates.

The sutures represent the area where much of the growth of the skull occurs during childhood .

As the individual ages, these sutures close. When the plates of bone fuse together, they form a solid piece of bone.

Eventually all sutures close, however most sutures take years to close. Some sutures are not closed until the individual is in their early 20s.

These sutures allow movement of the bones, this allows the bones to overlap as the baby moves through the birth canal, facilitating delivery.

But more importantly, it allows the baby’s brain and head to grow.

Craniosynostosis is a condition in which one or more of the sutures close earlier than expected.

Craniosynostosis means the bones of the skull together (skull related to the skull, syn means with or together (synergy) and osteo means bone).

When this happens, the growth of the skull in the closed suture slows or stops, but the brain continues to grow, which causes an increase in the growth of other areas where the sutures are open, causing deformations and there may even be an increase of the pressure inside the head.

Therefore, a predominant characteristic in this condition are changes in the shape of the skull or facial bones causing an atypical shape such as a cone or a flat head on one side, among others.

Even in some children, craniosynostosis can affect brain growth and development.

Causes of craniosynostosis

Craniosynostosis occurs in about 1 in 2,500 newborn babies and affects males slightly more often than females.

There is up to a 4% chance that a sibling born after a child with craniosynostosis will also have the disease. There is a similar risk for children of parents with craniosynostosis.

Craniosynostosis occurs in babies with and without a family history of the condition.

Sometimes it occurs as part of a genetic disorder or syndrome. There are more than 150 genetic syndromes known to cause craniosynostosis.

Some examples of genetic conditions with characteristic craniosynostosis are Crouzan syndrome, Pfeiffer syndrome, and Apert syndrome.

A geneticist can help the family understand the cause and future risks associated with a diagnosis of craniosynostosis.

When craniosynostosis is not part of a syndrome, non-syndromic or sporadic craniosynostosis, it is not inherited, which means it is not passed from parent to child.

Research suggests it could be caused by the position of the baby in the womb, medications taken during pregnancy, hormonal problems, but the truth is that no one knows for sure.

Types of craniosynostosis

Syndromic and nonsyndromic craniosynostosis is one way of classifying craniosynostosis (by cause).

Craniosynostosis can also be written by how many and which sutures are closed.

When describing the type of craniosynostosis, the number of sutures involved is chosen first (single, double, or complex multisuture) and then the name of the involved suture (metopic, sagittal, coronal, or lambdoidal) is chosen.

There are numerous types of craniosynostosis and depending on the suture or sutures involved, they include the following types:

Plagiocephaly

Plagiocephaly involves fusion of the right or left side of the coronal suture that extends from ear to ear. This is called coronal synostosis.

Characteristics of unicoronal craniosynostosis (anterior plagiocephaly) T5:

  • One eye appears narrower than the other.
  • One side of the forehead appears more prominent, while the other is flattened.
  • There is a slight curvature to the nose.
  • The ridge that runs from the top of the head down one side toward the ear.
  • It is more common in girls than boys.
Characteristics of Unilateral Lambdoid Craniosynostosis (Posterior Plagiocephaly)
  • Occiput flat (back of head) on one side. One ear may be further back and down, relative to the other ear.
  • A less common type of craniosynostosis that involves only one suture and is not caused by a known syndrome.
Characteristics of positional plagiocephaly

Positional plagiocephaly refers to an asymmetric misshapen head, due to repeated pressure on the same area of ​​the head.

This type of plagiocephaly is not a synostosis and is generally caused when the occipital bone flattens due to pressure, such as when the baby always sleeps on that part of the skull.

Scaphocephaly

Scaphocephaly comes from the word scapho refers to ‘boat’ and cephal refers to ‘head’, thus scaphocephaly means a boat-shaped head.

The sagittal suture is closed between the two soft points (the anterior and posterior fontanelles).

Again, the bones cannot move from side to side so the only way the head can grow is forward to back and the middle or back of the baby’s head will be long and narrow.

Characteristics of sagittal craniosynostosis (scaphocephaly)
  • Long and narrow head.
  • Prominent forehead and occiput (back of head).
  • Crest that runs from front to back along the top of the head.
  • Most common type of craniosynostosis.
  • More common in boys than girls.

Trigonocephaly

The metopic suture joins the bones on the left and right side of the skull between the bridge of the nose and the soft area (technically called the anterior fontanelle).

The closure of this suture means that the front of the skull cannot expand from side to side, only from front to back.

Babies with metopic suture synostosis will therefore have a ridge running down the middle of their forehead. The crest can make the forehead look almost triangular and the eyes very close.

Characteristics of metopic craniosynostosis (trigonocephaly)
  • The crest can make the forehead look almost triangular and the eyes close together.
  • Crest that rises and falls in the middle of the forehead.
  • More common in boys than girls.

Signs and symptoms of craniosynostosis

This condition causes changes in the shape of the head and face in babies. Synostosis can cause increased pressure within the skull, usually when there is a premature fusion of several sutures.

Some symptoms that occur with increased pressure in the skull include:

  • Bulging fontanelle
  • Drowsiness.
  • Very noticeable head veins
  • Irritability.
  • The baby screams a lot.
  • Lack of appetite
  • Vomiting
  • Increase in the circumference of the baby’s head.
  • You may have seizures.
  • Bulging eyes
  • The child has trouble looking up.
  • Developmental delays.

Diagnosis of craniosynostosis

A difference in the shape of the head does not always mean that a child has craniosynostosis, it can be a condition called deformational plagiocephaly, which is related to their sleeping position. Or, the child may simply have a normal variation in the shape of the head.

Early closure of its soft spot or a ridge on the skull does not always mean that the child has craniosynostosis. In some children, the soft spot closes early, and in others the skull has a ridge or two.

As some children with craniosynostosis grow older, it may take longer to reach milestones in their intellectual and physical development. Sometimes a child may have problems with eye movements and, rarely, with vision itself.

Diagnosis is made after a physical examination and review of the prenatal and birth history, with a review of the family history of craniosynostosis or other abnormalities and developmental milestones.

Your doctor may recommend additional tests. These diagnostic tests include:

  • X-ray images, MRI, CT scans form a clear view of the brain.
  • Genetic testing allows specialists to check for related syndromes.
  • “3D” photography helps specialists to make various measurements of the child’s head.

Treatment of craniosynostosis

The specialists collect all the information from the medical history, physical examination and images requested to provide an accurate diagnosis and formulate a treatment plan, taking into account the following:

  • The child’s age, general health, and medical history.
  • The type and extent of the condition.
  • The response and tolerance to certain medications, therapies or procedures.
  • The expectations of the condition for each individual.

Treatment for craniosynostosis may include:

  • Monitoring by surgeons.
  • Surgery.
  • Wearing a helmet.
  • Physical, speech, or occupational therapy if needed.

Craniosynostosis Surgery

Surgery is usually the recommended treatment, to reduce pressure on the head, provide space for the brain to grow and develop, and to correct bone deformities of the face and skull.

Surgery should preferably be done before the child is 1 year old. Most procedures are done between 3 and 8 months of age, because the bones are still soft, the sutures have not disappeared, and they have not fused with other bones.

However, surgery may be necessary much earlier, which will depend on the severity of the condition.

Because blood loss can be a problem with this type of surgery, surgery is often delayed in very young children to allow for some growth and development and increased blood volume.

Types of surgery
Endoscopic craniosynostosis surgery

The surgeon may recommend minimally invasive endoscopic surgery when your baby is between two and four months old and has only one closed suture.

The recommended age depends on the type of craniosynostosis the baby has. Endoscopic surgery may not work as well in older babies or when more than one suture has been closed prematurely.

Surgeons perform minimally invasive surgery through small incisions large enough for surgical instruments to enter.

Then a thin tube with a video camera and other instruments is inserted through the incisions. The camera allows surgeons to see inside the child’s head while performing surgery.

Once the camera and instruments are inserted, surgeons remove a narrow strip of bone along the closed suture, which opens the suture. Sometimes additional cuts are made in the skull without removing any bones, this helps reshape the skull.

After surgery, your baby may need to wear a special helmet to help mold the shape of his head. This helmet can be worn anywhere from a few months to a year or more.

Traditional open craniosynostosis surgery

Open surgery is the traditional surgical method to treat craniosynostosis. Surgeons may recommend open surgery if your baby is over four to six months old or has more than one closed suture.

Typically, surgeons recommend that babies with sagittal craniosynostosis undergo open surgery between three and twelve months of age.

Babies with coronal or metopic craniosynostosis have surgery between four and nine months of age.

However, surgeons can perform open surgery even when the baby is over a year old.

Surgeons create a wavy incision in the scalp. The position of the incision depends on where in the skull surgeons need to work.

Once the skull is exposed, surgeons can remove a strip of bone along the closed suture, which opens the suture.

When this is done, additional cuts can be made in the skull without removing any bones; This helps reshape the skull.

Or, surgeons do not remove a strip of bone and can instead make many cuts in the skull and reshape it extensively.

Babies who have open surgery generally do not wear a helmet to help reshape the skull.

However, older infants who are already beginning to walk usually wear a protective helmet for several weeks until the reshaped skull bone is strong enough that this protection is not necessary.

Problems after surgery can occur suddenly or over a period of time, experiencing the following:

  • Fever.
  • Vomiting
  • Headache.
  • Present irritability.
  • Swelling and redness in the areas where the incisions were made.
  • Present a decrease in alertness.
  • Present fatigue.

The appearance of any of these problems requires immediate medical attention.

Complications

Surgery can prevent complications from craniosynostosis. If the condition is not treated, the baby’s head can become permanently deformed and further complications can arise.

The skull will continue to grow in an unusual way, and this can affect other functions.

As the baby’s brain grows, pressure can build up inside the skull and without treatment, increased intracranial pressure can lead to additional complications, such as brain damage, slow mental development, blindness, and seizures.

If the craniosynostosis is mild, it may not be noticed until a later stage.

Panorama

The key to treating craniosynostosis is early detection and treatment.

Experts note that with proper treatment, most children with craniosynostosis will lead normal lives, especially if they do not have an associated genetic syndrome.

However, additional support may be necessary for those who:

  • They have other symptoms or changes that affect, for example, brain development.
  • They have an unusual head shape, even after surgery, as this can lead to problems with self-esteem

Most children who have surgery will have a normally shaped head and will not experience any cognitive delays or other complications.