Craniosynostosis (Skull Anomalies)
Craniosynostosis is the premature fusion of the bones of the skull, which are normally separate during pregnancy and remain open after birth. Early closure produces an abnormal shape to the head and may result in increased pressure within the skull. Craniosynostosis may be an isolated finding or may be seen in conjunction with other syndromes affecting the head and neck, as well as other organ systems. Craniosynostosis is seen in roughly 1 in 1,700 to 1,900 births.
Craniosynostosis can appear in different forms, which include the following four major types:
- Coronal synostosis: This occurs when one or both of the normal thin spaces that lie at the side of the skull prematurely fuse and separate the frontal and parietal bones. When this occurs, it appears as a short skull from front to back. When one side is involved, the face – especially around the eye sockets – is asymmetric. When both sides are involved, the skull is shallow and wide.
- Lambdoid synostosis: Infants with a lambdoid synostosis present with notable changes to the face, such as asymmetry or curvature. In addition, the bone in the back of the skull behind the ear is prominent and larger than the opposite side.
- Metopic synostosis: This type of craniosynostosis impacts the forehead and happens when two halves of the forehead prematurely fuse together. A child with this may have a pinched skull from the front that is triangular-shaped from above. A ridge may be pronounced down the middle of the forehead.
- Sagittal synostosis: The premature fusion of the normal thin space that lies at the top of the skull and separates the two parietal bones. A child with premature fusion of the sagittal suture presents with a long skull from front to back and a narrow skull from side to side. A ridge may be palpable at the top of the head.
Diagnosing a Craniosynostosis
The diagnosis of craniosynostosis may be made before birth on ultrasound or amniocentesis or after delivery by a physician. Examination will usually reveal the outward signs and/or symptoms. Confirmation of the diagnosis may be made by a number of imaging tests, including an ultrasound or a CT scan.
Cranial vault reconstruction is the treatment of choice for significantly pronounced craniosynostosis or when this condition causes increased pressure inside the skull. This surgical procedure is usually performed in the first year of life depending on the severity of the condition. It involves removing, reshaping, and replacing of the affected bones. The surgery usually takes several hours and patients stay in the hospital about a week prior to discharge. Follow-up is then in the office.