About Craniosynostosis

A baby’s skull serves as durable armor that protects one of the most sensitive organs in the known universe—the human brain—and yet must remain flexible enough to expand quickly in three dimensions, doubling in volume in a few short months.

The eight bones that make up a newborn’s cranium are connected by flexible strips of fibrous material called sutures. A baby’s brain grows quickly, and the sutures allow the bony parts of the skull to expand evenly to make room for it. Sometimes, though, those sutures fuse together sooner than they should and parts of the skull can no longer expand to accommodate brain growth. Increased pressure in the skull and a misshapen head may result. The premature fusion of one or more of the sutures is called craniosynostosis, a condition which afflicts about 1 in every 2,000 babies. Craniosynostosis can usually be corrected and controlled when treated at top centers such as Lucile Packard Children’s Hospital Stanford, and children who have been successfully treated typically go on to lead otherwise healthy and normal lives. 

Once potentially lethal and disabling, today craniosynostosisis a treatable condition. At Packard Children’s, we successfully care for dozens of cases of craniosynostosis patients every year. Packard Children’s and other leading research centers have both improved the prognosis for young patients and eased the experience of treatment. Today, most cases are resolved without complication.

Types of Craniosynostosis

The different types of of craniosynostosis are largely defined by which sutures and cranial bones are involved in the premature fusion. About half of all cases of craniosynostosis are sagittal synostosis, which occurs when the parietal bones that make up the back part of the top and sides of the skull fuse along the sagittal suture, which runs along the middle of the head from front to the back. When this occurs, the growing brain can no longer widen normally, and so the skull and the brain within it elongate.

The second most common type of craniosynostosis is called coronal synostosis, which occurs when one or both of the two frontal bones fuse to one or both of the parietal bones along the coronal suture, which runs across the middle of the head, roughly from ear-to-ear. If this happens on both sides, it is called bilateral coronal synostosis. In this condition, the head typically has trouble growing upward or forward, which results in a sloping and flattening of the forehead. If the fusion occurs on only one side, the head may grow asymmetrically, often with one ear shifting further forward and one side of the forehead protruding more than the other. Together, sagittal and coronal craniosynostosis make up 60 to 70 percent of craniosynostosis cases.

The third most common type of craniosynostosis is called metopic synostosis, which occurs when the frontal bones fuse along the metopic suture. This can result in a protruding ridge forming along the middle of the forehead.

The cause of the premature fusion also differentiates the major types of craniosynostosis. If a case is caused by an isolated malfunction in the sutures themselves, it is called primary craniosynostosis. Essentially, a defect in the suture’s programming instructs it to fuse before the time is right.

However, many cases are labeled as secondary craniosynostosis, which results from syndromic conditions typically caused by genetic abnormalities. These genetic differences can also cause symptoms elsewhere in the body, including ear abnormalities, limb defects or cardiovascular malformations.

Some forms of craniosynostosis have genetic causes that can be identified by laboratory analysis. Once unveiled, a hereditary form can be watched closely for secondary conditions, which may not present until much later in life.

Diagnosis and symptoms of craniosynostosis

Sometimes, ultrasound imaging reveals craniosynostosis when a baby is still in utero. More typically, though, craniosynostosis is discovered by a pediatrician who notices abnormal head or face growth in the first few weeks or months after birth. Elongation or asymmetry of the head and distorted facial features are all strong clues.

On the other hand, if multiple sutures fuse early (known as complex craniosynostosis), it leaves no room for the brain to grow. Pressure build-up inside the skull can cause a bulging of the fontanelle, along with sleepiness, prominent veins on the scalp, irritability, high-pitched crying, difficulty feeding, projectile vomiting, altered head growth rates, seizures, bulging eyes and developmental delays. Of course, many of these symptoms could have other causes. If in doubt, promptly consult a pediatrician.

Early diagnosis is better

The great majority of children who receive treatment for craniosynostosis are able to lead happy and healthy lives. However, if intracranial pressure becomes too great or persists too long, brain damage can result. Craniosynostosis stemming from underlying neurologic or developmental problems may also be more difficult to treat. In general, though, the earlier treatment begins, the more successful it will be and the easier it will be for a child patient. Even in the most straightforward cases of primary craniosynostosis, early detection increases the likelihood that minimally invasive surgical approaches will be effective.  Any child with craniosynostosis will need frequent medical evaluations after treatment to ensure that their skull, facial bones and brain all continue developing normally.

Multidisciplinary approach

Our multidisciplinary medical team works closely with every patient’s family to provide continuing education and guidance in order to ensure the best possible outcome and maximize the overall health and well-being of our young patients.