An infant’s skull is comprised of boney plates separated by sutures. Cranial sutures are strong, fibrous tissues that hold the bones together and they intersect in large soft spots known as fontanelles. The infant’s skull does not completely fuse until the age of two thereby granting the brain time to grow. Once the bones fuse, the sutures no longer remain flexible.
Craniosynostosis is due to premature fusion of one or more cranial sutures. It affects 1 in every 2000 to 2500 births worldwide. Premature closure of sutures restricts the growth of the skull perpendicular to the affected suture. To accommodate, the growing brain, the skull grows parallel to the affected suture resulting in a skull deformity. Craniosynostosis can involve one or multiple sutures; however, the sagittal suture is the most common. There is an increased incidence of craniosynostosis in multiple pregnancies and in presence of uterine abnormalities; however, craniosynostosis involving multiple sutures is often a product of a genetic syndrome such as Apert’s and Crouzon syndrome.
The different types of craniosynostosis are sagittal synostosis, frontal plagiocephaly, and metopic synostosis. Symptoms depend on the type of craniosynostosis but they may include no “soft spot” on the newborn skull, a raised hard ridge along the affected sutures, unusual head shape, and slow or no increase in head size over time as the infant grows. The diagnosis of craniosynostosis is based upon physical exam and radiographic studies such as X-ray and CT which can further illustrate structural abnormalities. Complications associated with craniosynostosis include increased intracranial pressure; inhibition of brain growth; impairment in cognition and neurodevelopment such as global development delay and poor feeding; and poor self-esteem and social isolation due to aesthetic abnormalities.
Management for this condition begins with a primary care provider recognizing an abnormal head shape and referring to a craniofacial team for evaluation, preferably within the first few weeks of life. The craniofacial team develops a treatment plan, coordinates future care, and monitors the patient’s progress. The intervention involves surgical repair of craniosynostosis to prevent intracranial hypertension. Signs of intracranial hypertension include papilledema, a beaten copper appearance on skull radiograph, or increased measured ICP requiring urgent decompression.
The timing of surgery depends upon the severity of the condition and the child’s health. Sometimes, surgery is performed at 8-12 months of age because the intracranial volume is sufficiently large and the child may better endure the stress of surgery. Also, the calvarium is thicker allowing more stable fixation. The different classifications of craniosynostosis require different surgical plans. Prognosis depends on how many sutures are involved and the child’s overall health. Individuals with this condition who undergo surgery generally improve and do well, especially when it is not associated with a genetic syndrome.