Morphometric comparison of foramen magnum in non-syndromic craniosynostosis patients with or without Chiari I malformation.

ABSTRACT

BACKGROUND: In order to compare the morphometry of foramen magnum (FM) in a matched-pair study, in children with non-syndromic craniosynostosis with and without Chiari I malformation (CMI), both brain magnetic resonance (MRI) and multidetector computed tomography (MDCT) images were utilized. METHODS: Brain MR images were retrieved from the Helsinki University Hospital Picture Archiving and Communications System to identify patients with CMI during 1.1.2004 to 31.3.2009. Age-, gender-, and craniosynostosis-matched controls were retrieved from the same cohort. Morphometric analysis of FM was carried out. RESULTS: Seven patients with non-syndromic craniosynostosis with CMI were recorded. In CMI patients, the absolute anteroposterior length was 33.4 mm as compared to 36.7 mm in controls (p = 0.023). The mean width was 28.1 and 29.9 mm (p = 0.29), and the cross-sectional area was 654.1 and 764.9 mm(2) (p = 0.11) in CMI and controls, respectively. In CMI patients, the relative anteroposterior length of the FM was, on average, 91 % of the control's measurements. On average, the width was 95 % and the cross-sectional area was 88 % of the control's results. CONCLUSIONS: In pediatric non-syndromic craniosynostosis patients, a statistically significant reduced anteroposterior diameter of the FM is found in patients with an adjacent CMI as compared to their age-, gender-, and type-matched controls of craniosynostosis.