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Craniosynostosis

Conditions

The word “craniosynostosis” is derived from the Greek and refers to a congenital premature fusion (closure) of one or more sutures on a baby’s skull.  Sutures are seams that connect individual skull bones. When these seams are open they allow the skull to expand in an even fashion when the brain grows in infancy. When a suture has closed too early, the skull cannot expand in a uniform fashion.  In some cases, this may lead to increased pressure on the brain (elevated intracranial pressure), which can produce signs and symptoms such as headache, inconsolability, visual changes and developmental delay.  Elevated intracranial pressure occurs approximately 13% of the time when a single suture is affected and up to 42% of the time when multiple sutures have fused early.

Patients can be seen by Texas Children's experts in Craniofacial Program.

Causes & Risk Factors

The cause of craniosynostosis is unknown. Genes may play a role. However, there is usually no family history that seems to lead to the condition.

One type that is passed down through families (inherited) can occur with other health problems, such as seizures, decreased intelligence, and blindness. Genetic disorders commonly linked to craniosynostosis include Crouzon, Apert, Carpenter, Chotzen and Pfeiffer syndromes.

However, most children with craniosynostosis are otherwise healthy and have normal intelligence.

Symptoms & Types

Symptoms depend on the type of craniosynostosis. They may include:

  • No "soft spot" (fontanelle) on the newborn's skull
  • A raised hard ridge along the affected sutures
  • Unusual head shape
  • Slow or no increase in the head size over time as the baby grows

Types of craniosynostosis:

  • Sagittal synostosis (scaphocephaly) is the most common type. It affects the main suture on the very top of the head. The early closing forces the head to grow long and narrow, instead of wide. Babies with this type tend to have a broad forehead. It is more common in boys than girls. 
  • Frontal plagiocephaly is the next most common type. It affects the suture that runs from ear to ear on the top of the head. It is more common in girls.

Metopic synostosis is a rare form that affects the suture close to the forehead. The child's head shape may be described as trigonocephaly (a triangular shaped forehead). It may range from mild to severe.

Diagnosis & Tests

Craniosynostosis is usually diagnosed by a specialist experienced in examining a child’s head shape, like a neurosurgeon or plastic surgeon.  The diagnosis is often made clinically; special x-ray tests, such as a CT scan, confirm the diagnosis by showing the fused suture. 

Craniosynostosis should be distinguished from plagiocephaly, a term that refers to a crooked head shape without a fused suture.  This distinction is critical to make, as craniosynostosis is usually addressed by surgery, whereas plagiocephaly is addressed by nonsurgical therapy.

Treatment & Care

If surgery is recommended for your child by our specialists, then a detailed discussion of the treatment options will be presented to you.  Typically, surgery is performed in infancy (3-9 months of age), depending upon the technique.  Our priority at Texas Children’s is to perform surgery when it is safe for your child and to minimize surgical and postsurgical risks.

1.  Modified Strip Craniectomy

This surgery involves removing the affected suture as a strip and making special cuts on the bones of the skull to allow the skull to reshape itself.  The surgery may involve a conventional open technique with a bicoronal (above one ear to above the other ear) incision or an endoscopic technique (see below), which is performed through 2 limited incisions.  The advantage of this technique is that the surgery requires less time than the calvarial vault reshaping technique (see below), which results in less bleeding and a shorter hospital stay.  The disadvantage is that the modified strip craniectomy may only be effective for certain types of craniosynostosis (e.g., sagittal type) and may result in relapse of the deformity, requiring more extensive surgery in the future.  In order for this operation to be effective, the surgery should be performed no later than 3 months of age. After surgery, patients must wear a helmet to help mold the head for a period of months after the surgery.

2.  Calvarial Vault Remodeling

Remodeling the skull bones involves temporarily removing them (craniotomy), reshaping them, and replacing them to form the skull in a new shape and arrangement.  The reshaped bones are secured using either synthetic plates and screws (which dissolve in a year’s time) or these plates and screws as well as dissolving sutures.  A clear advantage of this type of reconstruction is that it is the most versatile, allowing the surgeon exposure, access, and the ability to precisely reshape an area of or the entire skull.  Also, the bones are reshaped in one surgery and no helmet is required after surgery.  In general, the disadvantage of this approach is that it requires a bicoronal incision, more operative time, more blood loss, and a longer hospital stay.  This surgery is usually performed after 6 months of age, when a child’s skull bones have grown relatively thicker.  

3. Endoscopic Surgery

In this variation of surgery, a special “telescope” (endoscope) is used to assist the surgeon with visualization of the operative field.  It can be combined with a strip craniectomy technique, but not with the remodeling technique (see above).  This allows the surgeon to make one or two small incisions in the scalp, thereby avoiding the larger bicoronal scar.  This is the main advantage of this technique. Because of the smaller incision, endoscopic assisted surgery may compromise precision and access to bleeding areas of the skull.  Like the open modified strip craniectomy technique variation, endoscopic craniectomy has a similar hospital stay and requires a helmet after surgery and should be performed even earlier, by 3 months of age.  Lastly, the long-term outcomes of the aesthetic result from this type of surgery, compared to more traditional techniques such as cranial vault reshaping, is not as well-studied, though early results are very good

Living & Managing

The doctor may recommend for your child to wear a protective helmet after the surgery for a period of time.

Children with this condition who have surgery usually do well, especially when the condition is not associated with a genetic syndrome.

Related Topics

References & Sources

http://www.nlm.nih.gov/medlineplus/ency/article/001590.htm