What is Craniosynostosis?

Craniosynostosis is defect at birth where one or many joints between the bones of an infant’s skull close up prematurely before the brain forms completely. When a baby has Craniosynostosis, their brain cannot develop to its natural shape, leaving a misshapen head.  As the brain of an infant develops and grows, it will exert an evenly spaced amount of pressure the bones of the skull. If problems happen, brain growth cannot happen evenly resulting in the misshapen head.

Types of Craniosynostosis

  • Sagittal synostosis:   This is the most commonly diagnosed craniosynostosis caused by the premature fusing of the part of the skull that runs front to back right through the middle.  It separates the left and right sides of skull.
  • Unilateral or bilateral coronal synostosis: This is another commonly diagnosed form of craniosynostosis. It’s caused by the fusing of part of the skull which runs crosswise on the top of the skull from one ear to the other.
  • Lambdoid synostosis: This is caused through fusing of part of the skull located on the back shaped in an inverted V.  Normally with Lambdoid synostosis, one side of the skull fuses, but occasionally both sides end up fused together.
  • Metopic synostosis: This is far less common, and is caused by fusing of the part of the skull running from the top down through forehead all the way to the nose.

What are the Symptoms of Craniosynostosis?

Symptoms of this defect include:

  • Misshapen skull
  • Intracranial pressure within the skull
  • An abnormal or disappearing soft section of the baby’s skull
  • Minimal to no growth of the head
  • Development of a hard ridge along affected areas

Craniosynostosis Causes

Genetics and congenital factors are dominating attributes when it comes to the causes of craniosynostosis. Babies born into families with high rates of craniosynostosis have a tendency to develop the suture fusion characteristic of the disease. Fetal head strain during pregnancy seems to be a major factor. Increased head stress can lower the expression of the IHH (Indian Hedgehog) protein, a protein important in the development of the skull. The genes most often associated with craniosynostosis are TWIST and FGFR. These genes are involved in the production of the fibers needed for the skull to produce its proper shape.

Although most of the factors affecting craniosynostosis are biological, there are certain environmental factors at work. Maternal smoking appears to have a strong correlation to craniosynostosis. Additionally, exposure to certain amine-containing drugs appears to have a strong connection to the development of craniosynostosis. These factors may explain at least one-third of the variation in craniosynostosis rates.

How is Craniosynostosis Treated?

Surgery is the only treatment option available to correct Craniosynostosis. A paediatric neurosurgeon and craniofacial plastic surgeon may work together to come up with the most effective surgical options. Surgery for Craniosynostosis will usually be scheduled within the first year or two of the child’s life, or possibly for later on in childhood depending on the seriousness of the condition.

Craniosynostosis Prevention

Due to the hereditary nature of craniosynostosis, most prevention will rely on preventing the births of babies with the condition. Genetic screening can help women identify any issues prior to birth in order to make sure they are not giving birth to a baby at risk. These methods are highly effective, but there are environmental factors that must be addressed to prevent craniosynostosis as well. Cranial stress in the womb is absolutely a major factor in the formation of the head and it can be severely harmed if doctors do not take steps to monitor it. With good care, poor suture formation is highly avoidable. A new development to prevent craniosynostosis is to give women supplements and medication in order to counteract the effects of environmental and congenital factors. Vitamin D levels, essential to bone development, and vitamin A levels, which are essential to gene expression, play a central role in this.

Last Reviewed:
September 19, 2016
Last Updated:
December 11, 2017