Background and aims Children with syndromic or complex craniosynostosis have a prevalence of 68% of obstructive sleep apnea (OSA), which has been associated with an increased risk for developing elevated intracranial pressure (ICP). The objective of this study was to evaluate how often and to what extend OSA increases the risk of elevated ICP in patients with syndromic and complex craniosynostosis and to prospectively evaluate our current clinical treatment protocol.

Methods A prospective observational cohort study of patients with syndromic or complex craniosynostosis treated at the Sophia Children’s Hospital, started in January 1st 2007. All patients received repeated sleep studies and fundoscopy (to evaluate papilledema as proxy for elevated ICP), according to a standardised protocol.

Results Sixty-two patients underwent full analysis, with a mean age at time of latest follow-up of 6.0 years. Mean age at first presentation of papilledema was 1.9 years (range 0.4–6.0). Twenty-three of 62 patients (37.1%) had papilledema, of whom 13 (21.0%) pre-operative. Thirty-nine of 62 (62.9%) patients had OSA. Compared to patients without OSA, papilledema was not more frequently present in patients with mild or moderate OSA. However, patients with severe OSA had pre-operatively significantly more often papilledema (p = 0.015).

Conclusions Children with syndromic craniosynostosis are at risk of elevated ICP due to a complex interaction of risk factors. The relationship between mild and moderate OSA and elevated ICP is weak, however in individual patients OSA may be the decisive factor. Severe OSA significantly increases the risk of elevated ICP.