The skull is made up of several flat bones that fit together like the pieces of a jigsaw puzzle. The joints between these bones usually remain loose and open during growth and development to allow the brain to grow and expand. These joints are called “sutures.” Craniosynostosis is the condition in which these sutures grow together or become fused prematurely. When that happens, the skull can no longer stretch and expand to accommodate the growing brain in the area where the sutures have fused. In some cases, the result is increased pressure on the growing brain.
Is this condition painful?
In general, craniosynostosis is not a painful condition. However, if there is increased pressure upon the brain, this can cause headaches, irritability, nausea, and vomiting.
What are the different types craniosynostosis?
There are multiple different cranial sutures. There can be fusion of one suture or multiple sutures. Each type of suture fusion is associated with a particular type of head shape. Fusion of the metopic suture causes a triangular forehead shape, or trigonocephaly. Fusion of the sagittal suture causes a long, narrow head shape, or scaphocephaly. Coronal suture fusion causes flattening of the forehead on the affected side, called anterior plagiocephaly. When both coronal sutures are fused, the skull becomes tall and short from front-to-back; this is called brachycephaly, or turribrachycephaly. Fusion of the lambdoid sutures is causes flattening of the back of the head on the side of the affected suture; this is caused by posterior plagiocephaly.
Lots of babies have slightly abnormal head shapes; how do I know when it is something to worry about?
Abnormal head shapes in babies are quite common. In general, abnormal head shapes can be caused by either craniosynostosis, which is described above, or by external forces that push on the skull to deform it. The latter condition is much more common and is called deformational plagiocephaly. Deformational plagiocephaly does not cause any increased pressure on the brain and is not associated with any danger to the neural development of the child. The most common form of deformational plagiocephaly is flattening of the back of the head, caused by repetitive sleep positioning.
If your baby has an abnormal head shape, you should raise this concern with your pediatrician. Often the pediatrician will be able to distinguish whether your child has the much more common deformational plagiocephaly or the much less common craniosynostosis. If the pediatrician in unsure, then you should be referred to see a craniofacial surgeon, who can usually make the diagnosis by physical exam.
Who gets craniosynostosis?
Craniosynostosis can occur in any newborn infant. Some cases are “sporadic,” meaning that there is no family history. However, other cases may have a family history or be part of a syndrome (see below). Metopic and sagittal synostosis are more common in boys than in girls.
What causes craniosynostosis?
There are three main theories that have been proposed to explain craniosynostosis. Most likely, as with many other congenital anomalies, multiple factors can contribute to this condition. Craniosynostosis can be caused by a genetic mutation, as in some syndromes like Apert’s syndrome. Alternatively, there is evidence that mechanical forces can create suture fusion; for example, when the brain is very small and is not expanding or growing normally, the cranial sutures can fuse prematurely because there is no force from the brain keeping them open. Finally, there is the theory that there is some intrinsic biochemical abnormality of the sutures themselves that causes them to fuse prematurely.
What are the main issues related to craniosynostosis?
The most important issue related to craniosynostosis is the potential for increased pressure on the brain. When there is excessive pressure on the brain, problems with neural development, including visual problems can occur. These may be subtle or mild, such as learning disabilities, or more severe, such as mental retardation and loss of vision. Most children never develop such severe symptoms. However, because we cannot predict which children will have these problems, treatment of the craniosynostosis is recommended to prevent the possible increased intracranial pressure.
Are there other problems that occur commonly with craniosynostosis?
Some types of craniosynostosis occur as part of a syndrome, or a collection of abnormalities that affect different parts of the body. Most commonly, these other abnormalities affect the face and hands. Specifically, the face may not grow forward normally, and appear retruded, flat, or dish-like. In addition, the hands may have webbed fingers (syndactyly), extra digits (thumbs usually), small thumbs, large thumbs, and other types of abnormalities. Most of these syndromes have a genetic basis, and some of these genetic abnormalities can now be identified by testing.
What is the treatment for babies with craniosynostosis?
While every patient is treated individually, with treatment plans made specifically for him or her, some generalizations are possible. Treatment for craniosynostosis is surgical. Babies with craniosynostosis are examined early in life by members of the craniofacial treatment team: a pediatrician who specializes in treating infants with craniofacial anomalies, a geneticist, a craniofacial surgeon, a neurosurgeon, and an ophthalmologist. Depending on the particular case, other specialists may be involved also. A computerized tomography scan (CT scan)—a special type of x-ray—is performed to study the bones of the skull and the brain. If there are no signs of increased intracranial pressure by physical examination or by CT scan, then most children will have their surgery at approximately one year of age. If there is increased intracranial pressure, then surgery is performed sooner; also, patients with sagittal synostosis usually are treated at an earlier age.
The surgery is performed jointly by the craniofacial surgeon and the neurosurgeon. The skull is enlarged, or expanded, by removing and reshaping the bones of the skull to give the brain room to grow and also to correct the abnormal shapes that occur as a result of the various types of craniosynostosis. While this is a very specialized and complex surgical procedure, it is now performed safely and effectively with modern anesthetic and surgical techniques.
In some selected cases, another surgical method may be an option. This is a less invasive procedure that involves removing a large strip of bone containing the fused suture through small incisions, sometimes using an endoscope to allow better visualization (“Endoscopic Strip Craniectomy”). After the surgery, a custom-made molding helmet is used to reshape the skull. The success of this procedure depends upon the use of a molding helmet for many months after surgery. Dr. Muzaffar will discuss with you whether your child is a candidate for this type of surgery at your initial consultation.
What is done between the time my baby is born and the surgery?
After their initial Craniofacial Team evaluation, described above, the child is evaluated periodically to ensure that he or she is growing and developing normally and that there is no sign of increased intracranial pressure. The CT scan may be repeated at some point before the surgery. Your surgeons will meet with you several times to examine your baby and to ensure that all of your questions about the surgery are answered and that you feel comfortable with the whole process.
What sorts of specialists will be involved in my baby’s care?
The optimal treatment of children with craniosynostosis is achieved in a multidisciplinary setting. As noted above, these children may have a number of other medical issues that must be addressed, especially if they have a syndrome. Usually, the specialists involved include the craniofacial surgeon (a plastic surgeon who has done additional specialized training), a neurosurgeon, a pediatric ophthalmologist, a developmental pediatrician, a geneticist, the pediatric plastic surgery nurse, and an orthodontist.
Will we get to know our surgeon?
Because children with craniosynostosis are followed closely before, during, and after their surgery, you will become very familiar with your surgeons. Treatment is not finished after the surgery, because it is important for us to continue to monitor your child’s growth and development over the long term. This long-term surveillance involves physical examinations and periodic CT scans to ensure that there are no signs of any problems. Your surgeons will guide you and help you through the surgery and postoperative period.