Craniosynostosis is a condition which affects a baby’s skull. It changes the baby’s appearance and can potentially lead to blindness, brain damage or seizures.
A newborn’s skull consists of plates of bone which are separated by flexible, fibrous joints called sutures. Normally, these sutures become fused bone at around two years of age. If the skull plates join together too early, it is called “synostosis.” This can occur at one, two or multiple suture lines in the skull.
Based upon the sutures involved, different patterns of a misshapen head occur. These include:
- Sagittal suture This suture runs down the center of the head between the two soft spots. Early closure of the sagittal suture results in scaphocephaly (skaf-ə-ˈsef-ə-lē). The head appears long and narrow with a prominent forehead. It is the most common form of craniosynostosis.
- Coronal suture, one side This suture starts above and in front of the ear to the soft spot (fontanelle) in the front. Early closure flattens the forehead on that side, raises the eye socket up, and pulls the nose toward that side. It is called anterior plagiocephaly (plā-jē-ō-ˈsef-ə-lē).
- Coronal suture, both sides The head is broad and short. It is called brachycephaly (bra-ki-ˈse-fə-lē).
- Lambdoid suture, one side This suture is on the back of the skull. It runs from behind the ear to the smaller soft spot on the back of the head. Early closure flattens the back of the head and pulls the ear back and down on that side. It is called posterior plagiocephaly (plā-jē-ō-ˈsef-ə-lē).
- Metopic suture This suture runs in the middle of the forehead up to the front soft spot. Early closure makes the head look triangular in shape when viewed from above. It is called trigonocephaly (trigənōˈsefəlē).
Signs and Symptoms
The most common sign of craniosynostosis is a misshaped skull at birth or in infancy. A soft spot (fontanelle) may disappear early. A raised ridge may be felt in place of the edges along the suture line. Over time, the baby’s head size (head circumference) will not grow as it should and the baby’s head and face may not look normal. Depending on which sutures are involved and the age, the skull may restrict growth of the brain causing increased pressure. This can lead to things like developmental delay, seizures or blindness. In older children, the deformities of the face and head can result in poor self esteem and social isolation.
The cause of craniosynostosis is not known. Issues with the genes and the mother’s environment, food, drink and medications may play a role. The use of some fertility medicines (e.g. clomiphene) and maternal thyroid disease have been associated with an increased chance for craniosynostosis. It is also seen in some genetic syndromes.
The diagnosis of craniosynostosis is essentially made on the physical examination. Common tests include: computed tomography ( CT ), magnetic resonance imaging ( MRI ) or cranial ultrasound (especially in the evaluation of newborns). Genetic testing may be used, especially if there are concerns over craniosynostosis being related to a genetic syndrome.
In general, surgery during the first year of life is the treatment for craniosynostosis. In some instances, when the problem is mild and covered by hair, it may not be necessary.
When surgery is performed within the first six months of life, an endoscopic approach may be possible in some instances. The baby will then need to wear a helmet through the first year of life.
Standard open surgery is done by a pediatric neurosurgeon along with a craniofacial or plastic surgeon in most cases. It may take several hours, depending on the type of repair needed. The incisions are usually hidden behind the hairline. The surgeons work together to reshape the skull (and facial bones if needed) to create a more normal appearance and relieve pressure on the brain. The bones are then held together by very small plates and screws that resorb (breakdown and disappear) on their own. A helmet is not needed after open surgery. The baby is usually in the hospital for a few days.