Severity of Unilateral Coronal Synostosis Linked to Intracranial Volume.

Severity of unilateral coronal synostosis (UCS) varies and can affect intracranial volume (ICV), and intracranial pressure. Correlation between ICV and severity according to Utrecht Cranial Shape Quantifier and presence of papilledema as sign of raised intracranial pressure is determined. The authors included patients with UCS (≤18 months). Intracranial volume was calculated on preoperative CT scans by manual segmentation (OsiriX [Fondation OsiriX, Geneva, Switzerland]). Calculated ICV was compared to Lichtenberg normative data for control patients. When present, papilledema was noted. Utrecht Cranial Shape Quantifier was used to quantify severity using the variables: asymmetry ratio of frontal peak and ratio of frontal peak gradient. Severity of UCS was correlated to ICV using Pearson correlation coefficient. Mean age at CT scan of patients with UCS was 7 months (1-18 months). Mean calculated ICV was 870.96 mL (617.31-1264.46 mL). All patients had ICV between ± 2 SD curves of Lichtenberg; 10 had an ICV between -1 SD and +1 SD. Majority of ICV in girls was at or larger than normative mean, in boys ICV was mostly lower than normative mean. Pearson correlation coefficient between severity of UCS and ICV was negligible (r = -0.28). Preoperative papilledema during fundoscopy was found in 4.5% (1/22; ICV 1003.88 mL; severe UCS). Therefore, severity of UCS does not correlate to ICV. Despite varying severity of UCS, ICV remains within normal ranges.