Craniosynostosis: Symptoms and Causes | Tampa General Hospital


Craniosynostosis is a birth defect in which the bones in a baby’s skull join together too early. 

A typical baby’s skull has spaces between the bones (sutures) filled with flexible material. During infancy, the sutures remain flexible to provide space for the brain to grow. In a baby with craniosynostosis, one or more of the sutures close prematurely before the brain is fully formed. This can limit or slow the growth of the brain. Researchers estimate that about 1 in every 2,500 babies is born with craniosynostosis in the United States.

Causes of Craniosynostosis

The causes of craniosynostosis in most infants are unknown. However, many cases of craniosynostosis are thought to be related to a genetic disorder.

Other risk factors associated with craniosynostosis include:

  • A deficiency in the mother’s diet
  • Certain medications taken during pregnancy
  • Maternal thyroid disease

Symptoms of Craniosynostosis

The signs of craniosynostosis are usually noticeable at birth and become more apparent during the first few months of the baby's life. The symptoms and severity can vary depending on how many sutures are fused and the level of brain development at the time the fusion occurs.

General symptoms can include:

  • A misshapen skull, with the shape depending on which of the sutures are affected
  • An abnormal feeling or disappearing fontanel on the baby's skull
  • Development of a raised, hard ridge along affected sutures
  • Slow or no growth of the head as the baby grows

Diagnosis of Craniosynostosis

Craniosynostosis is usually diagnosed soon after a baby is born. Doctors can often identify craniosynostosis during a physical exam by feeling the baby’s head for hard edges along the sutures and unusual soft spots as well as examining the shape of the baby’s face. If a doctor suspects that a baby has craniosynostosis, the doctor will typically request one or more tests to help confirm the diagnosis, such as:

  • A special X-ray
  • A CT or CAT scan
  • An MRI

Treatments for Craniosynostosis

Babies with very mild craniosynostosis might not need surgery. As the baby gets older and grows hair, the shape of the skull can become less noticeable. Sometimes, special medical helmets can be used to help mold the baby’s skull into a more regular shape. Many types of craniosynostosis, however, end up requiring surgery.