Intracranial volume in patients with nonsyndromal craniosynostosis.

OBJECT: In recent years, comparisons between intracranial volumes (ICVs) in patients with craniosynostosis and healthy patients have given variable results, leading to questions regarding the validity of the normal reference material and the comparability of the measurement techniques. In this study, ICVs in patients with nonsyndromal craniosynostosis without previous surgical intervention were compared with the ICVs of a normal population of European descent determined using the same method for each group.
METHODS: Determination of ICV was based on measuring the area of intersection in each computerized tomography slice. For comparisons the ICV measurements for each patient were standardized with regard to age and sex by expressing them in terms of the standard deviation score. Only the group of boys with metopic synostosis had a tendency toward smaller ICV than did healthy boys (p = 0.04). Partitioning the male metopic data into age groups younger and older than 7 months of age revealed that the younger children had normal ICVs, whereas the older children had, on average, smaller ICVs (p = 0.02). Both the female sagittal synostosis and the male unilateral coronal synostosis groups had larger than normal ICVs, both with a probability value less than 0.001.
CONCLUSIONS: No evidence was found that the ICVs of patients with nonsyndromal craniosynostosis are smaller than those of normal children, except for boys older than 7 months of age with metopic synostosis. This finding may have implications for the timing of surgical intervention for these patients. The indications are that interventions should be focused less on ICV and more on normalizing craniofacial shape and promoting normal development.