Positional skull deformities in children: skull deformation without synostosis.

BACKGROUND: Patients with craniosynostosis are readily diagnosed by clinical and neuroimaging findings. Surgical treatment is indicated for preventing neurological deficits and for correcting esthetically unacceptable head deformities. In recent years, we have witnessed a progressive number of neurosurgical consultations for abnormal head shapes unrelated to premature fusion of the cranial sutures, especially of positional plagiocephaly. There have been descriptions of abnormalities in the cerebrospinal fluid (CSF) spaces in children with craniosynostosis.
OBJECTIVES: The aim of the present study was to investigate the role of the changes of the CSF spaces in the development of positional skull deformities in children. PATIENTS AND METHODS: The authors reviewed demographic, clinical, and neuroimaging data of 23 patients assessed for some form of nonsynostotic skull deformity (group A). The results were compared with those of a simultaneous group of nine infants diagnosed with benign extracerebral collections of fluid (group B).
RESULTS: The study group was composed of 11 boys and 12 girls, aged 3 years or younger. Seventeen children had plagiocephaly, four scaphocephaly, and two brachycephaly. Sixteen children (15 with plagiocephaly and 1 with brachycephaly) exhibited enlarged subarachnoid CSF spaces. In group B, the boy/girl ratio was of 7:2. Infants in group A presented at an older age (mean 12.7 months) than group B (mean age at presentation of 7.17 months). Children with benign extracerebral fluid collections were born with a head circumference (HC) greater than infants with positional skull deformities (p=0.005). The percentile of the children's HC at consultation was also larger for children of group B (p=0.03). The form of clinical presentation differed between the two groups. Most infants of group A were seen because of a type of head deformity, and children in group B were studied for macrocephaly. Long-term follow-up assessment showed better outcomes for patients in group B than for children of group A in regard to regression of initial symptoms (p=0.03).
CONCLUSIONS: Most positional head deformities appear to be related with the children's positioning for sleeping. We have not confirmed macrocephaly as a contributing factor for positional deformities. The distribution of extracerebral CSF and the presence of abnormal collections of fluid in children with positional head deformities do not seem to be related with the findings of pericerebral CSF encountered in children with benign extracerebral collections of fluid. In our view, brain pulsations, transmitted to these accumulations of CSF, play an important part in the development of the infants' skull deformities (p=0.02). The findings of enlarged CSF spaces in children with nonsynostotic skull deformation constituted an age-related event, as these collections tended to disappear as the children grew older (p=0.04).