Intracranial volume measurement of sagittal craniosynostosis.

We report 41 cases of non-syndromic isolated sagittal synostosis in which evaluation of intracranial volumes was undertaken. Twenty-six were male and fifteen were female. The measured intracranial volumes were then compared with normal age-corrected values. We have found that intracranial volumes were significantly larger than the normal population intracranial volumes in both sexes. However the statistical significance of this finding was much greater in females, (p<0.00002), than males (p<0.040), which was only of borderline significance. The results confirm smaller, earlier studies that intracranial volumes in sagittal synostosis patients are larger than average for age-corrected normal values. Analysis of a sub-set of six patients with sagittal synostosis who were found to have a common polymorphism 294C>T (Asn294Asn) in FGFR3 (fibroblast growth factor Receptor 3) on genetic testing were compared to age and sex matched cases of non-syndromic sagittal synostosis (without an underlying mutation) which confirmed that there were no discernable differences in intracranial volumes between the two groups. We conclude that this investigation supports the role of cranial re-shaping to improve cosmesis as the primary aim of surgical correction in this condition, in the absence of raised intracranial pressure.