The Types, Causes, and Treatment of Craniosynostosis

In today's article, we'll tell you about the types, causes, and treatment of craniosynostosis, a congenital medical condition characterized by deformities in the cranial vault.

Written and verified by the doctor Diego Pereira.

Last update: 27 May, 2022

If you want to know more about the types, causes, and treatment of craniosynostosis, keep reading.

Craniosynostosis is a congenital medical condition characterized by deformities in the cranial vault.

The cause is the premature closure of the cranial sutures. These sutures have the function of joining the bones of the skull and facilitating their movement during birth. So, after birth, these sutures close as the weeks go by.

This disease can cause severe complications if it doesn’t receive proper treatment.

Let’s take a closer look.

The types of craniosynostosis

Since there are several sutures in the skull, craniosynostosis is classified according to the one that’s closed prematurely. The greater the impediment to brain growth, the greater the severity. Here are some of the types:

1. Scaphocephaly

When the sagittal suture (which joins the two parietal bones) closes prematurely, a case of scaphocephaly occurs. It’s the most common, according to a publication by the Centers for Disease Control and Prevention (CDC). Patients have a wedge-shaped skull, making it more elongated in the anteroposterior axis.

2. Plagiocephaly

In this case, the suture involved is the coronal suture. This extends from the lateral part of the skull to the sagittal suture. Although this structure is found on each side, plagiocephaly refers only to unilateral closure. This case involves a flattening of the forehead on the corresponding side.

3. Trigonocephaly

From a clinical point of view, it involves a flattening in the shape of a triangle with a lower vertex on the patient’s forehead. It’s rare and is due to premature closure of the metopic suture. This extends from the upper portion of the nose to the sagittal suture.

4. Brachycephaly

Remember how in plagiocephaly, one of the two coronal sutures closes? In some cases, the defect may be bilateral. In this case, brachycephaly occurs. The malformation consists of a reduction of the anteroposterior diameter, therefore elongating the head upwards.

5. Oxycephaly

This term is ambiguous, as it can mean either premature closure of all sutures or a combination of the coronal suture and any other suture. Due to the important limitations for brain growth, it’s the most severe type. It often occurs along with other congenital defects, such as the fusion of two or more fingers (syndactyly).

Causes of craniosynostosis

In most cases, the exact cause of this group of diseases is unknown. There are several syndromes associated with genetic mutations in which the incidence of craniosynostosis is higher. Some of them are Apert syndrome and Crouzon syndrome, both characterized by multiple facial malformations.

As for environmental factors, several risk factors have been identified. These are conditions that increase the probability of a child being born with this condition. Some of them, whose exposure occurs during pregnancy, are the following:

• Tobacco use
• Thyroid illness in the mother
• Use of clomiphene citrate

Symptoms of craniosynostosis

The clinical manifestations depend on the severity of the malformations. Of course, these are worse in the case of syndromic craniosynostosis, which is associated with other genetic diseases.

Many of the symptoms are difficult to determine in the first months of life. So, patients may present constant crying and irritability. In addition to the obvious skull malformation, some of the most important symptoms are the following:

• Headache
• Decreased visual acuity
• Delayed psychomotor development
• Abnormal development of head circumference

Possible complications

Complications arise when treatment doesn’t begin promptly, something that can happen due to a delay in diagnosis. Some of these clinical conditions can be life-threatening, while others compromise the patient’s future quality of life. The most frequent are the following:

• Endocranial hypertension syndrome: When there’s a constant restriction of brain growth, the existing pressure may exceed the bearable limits. The characteristics of this syndrome include constant vomiting, severe headache, and loss of visual acuity.
• Mental retardation: If the malformation is very complex or doesn’t receive treatment, it may compromise cognitive development.
• Optic atrophy and blindness: As a consequence of the increased pressure inside the skull, the optic nerve may suffer irreparable damage over the months.
• Seizures: This is also a consequence of brain growth restriction and increased pressure in the cavity.
• Self-esteem problems: In the case of an unresolved deformity, it can lead to serious bullying problems. This and other psychological problems are frequent in these patients.

The diagnosis of craniosynostosis

If there’s adequate prenatal monitoring, especially in those mothers with risk factors, it’s possible to make the diagnosis during intrauterine development. This can be using a morphological ultrasonogram, which usually takes place from 20 weeks of gestation onwards.

After birth, the diagnosis is usually immediately evident. However, in mild cases, doctors may miss it. Since, in normal cases, all sutures must be permeable for the fetus to pass through the birth canal, small deformities may become visible in the first few hours of life, causing the craniosynostosis to be overlooked.
Over time, these malformations become more evident. At this time, the diagnosis can occur during a pediatric evaluation, in which the physician notices the absence of the anterior fontanel.

This is a space located at the front of the skull, just at the point of communication of several sutures. It usually closes spontaneously before the age of two years.

The treatment of craniosynostosis

Neurosurgery is the definitive treatment of craniosynostosis. However, it only takes place in cases with certain conditions.

In fact, mild cases may not require intervention. Over time, the development of the skull usually normalizes. In some cases, doctors can even prescribe special helmets to shape its development.

When a child requires surgery, its purpose is to reduce the deformity and promote proper growth of the skull. Subsequently, these patients often require ongoing medical consultations. That’s because many cases of craniosynostosis have to do with genetic syndromes. Also, it’s because there may be complications related to neurodevelopmental defects.

What to remember about craniosynostosis

Craniosynostosis is a common deformity that requires medical evaluation in all cases.

If someone close to you has a suspected case that hasn’t yet been diagnosed, it’s important to see a pediatrician. The professional will perform an initial evaluation and may refer the patient to a neurosurgeon.