WPI-13 Lack of association of cranial lacunae with intracranial hypertension in children with crouzon syndrome and apert syndrome: a 3D morphometric quantitative analysis

Objectives Cranial lacunae on CT is equivalent to the plain X-ray ‘copper beating’ seen in craniosynostosis. Copper beating has not been shown to correlate to intracranial hypertension (IH). However it is a purely quantitative assessment – can qualitative measurement of CT cranial lacunae more accurately predict IH in children with craniosynostosis? Design Retrospective cohort study. Subjects 18 consecutive children with Crouzon and 17 with Apert syndrome were identified. Methods Patients were divided into IH and non-IH groups defined on an intention to treat basis. 3D software was used to analyse% of calvarial lacunae. Results Mean age at CT scan was 380 days (range 6–1778). Of the 35 children, 21 required surgery for raised ICP (17 posterior vault expansion 2 ventriculo-peritoneal shunts (VPS), 1 spring-assisted cranioplasty and 1 fronto-orbital advancement) at mean age of 512 days (range 38–1710). Of the 21 children with raised ICP, 15 had lacunae with mean lacuna/calvarium percentage of 3% (0%–28%). Of the 14 non-raised ICP children, 8 had lacunae with mean lacuna/calvarium percentage of 2% (0%–8%). T-test demonstrated no significant difference between the 2 groups. For both groups, parietal bones were most likely to show lacunae (IH 14/21, non-IH 9/14), followed by occipital (IH 8/21, non-IH 3/14), followed by frontal (IH 6/21, non-IH 2/14). Conclusions Results suggest that cranial lacunae, measured using quantitative 3D methods, do not predict IH, in agreement with evidence from qualitative plain skull radiograph studies.