Single Suture Craniosynostoses: Physical Traits

Problems caused by sutural fusion:
Does a single sutural synostosis affect a child’s development or intelligence? This is a difficult question to answer. At the current time, we believe it either does not effect a child’s mental development, or if it does, it cannot be measured by current testing. There are a number of studies that have been published, which examine the possibility that there may be raised pressure inside of the skull of children born with craniosynostosis. The concern is that if the growing brain is kept from enlarging inside the skull because a suture has closed prematurely, then as the space inside the skull gets more crowded, pressure can build up. Studies suggest that a small percentage of children born with a single fused suture will have raised intracranial (inside the skull) pressure, and when these children with craniosynostosis were studied with I.Q. testing, it was noted that the children with the highest pressure had lower I.Q.s. The problem is that these were not well-designed studies. To begin with, no one is sure what the normal pressure is inside an infant’s skull, so it is hard to determine exactly what level of pressure is necessary to cause lasting problems. In addition, we know that pressure inside the skull normally varies up and down and does not stay constant. Furthermore, in some of the studies showing that children with raised intracranial pressure have lower IQ’s, it turns out that those children with the lowest IQ’s had syndromes that are known to have an abnormal brain structure (we know that the brain may not be wired normally in some syndromes). Finally, the I.Q. test examines only one form of intelligence; there are no good tests for measuring creative intelligence, artistic intelligence, musical intelligence, social intelligence, “common sense”, and other types of intelligence. Nevertheless, there are some on-going studies that raise the possibility that over the course of a number of years, untreated single sutural craniosynostosis might lead to higher intracranial pressures.

There are also some studies that suggest that children with single sutural synostosis may have a higher rate of experiencing some minor developmental or behavioral problems. Once again, it is not clear that these studies are good ones.  One of the many criticisms of these studies is that they do not compare their test results to children who are otherwise similar to those with craniosynostosis. There is always the possibility that the two groups (those with synostoses versus those without) may differ in home environments, parental influences, etc. It is known that if one performs developmental testing (or looks for behavioral issues) on a large group of children without craniosynostosis, about 20% of children will normally show some problems. Currently, we cannot be sure if single sutural craniosynostosis is more likely to cause developmental or behavioral issues. We also do not know the answers to a number of other good questions such as: does surgery help to prevent developmental problems?  Are there different problems specific to the different fused sutures?  Is the brain less affected in those cases where the skull is less affected?  It has been our experience that the vast majority of children with a single sutural synostosis are normal children who just have early closure of one of their sutures.

Other common features of all single sutural synostoses:
Skull | Fusion of the Suture
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