Incidence of increased intracranial pressure after early surgical treatment of syndromic craniosynostosis

The late development of intracranial hypertension after an aesthetically successful cranial vault expansion has been noted anecdotally in children with syndromic synostosis. If untreated, this process can lead to neurological and visual deterioration; however, the frequency of this problem is uncertain. In an attempt to detect this process before the onset of irreversible impairment, the authors have since 1991 incorporated routine ophthalmological evaluations into the multidisciplinary follow-up protocol for all patients with complex cranio-synostosis. These examinations were performed at initial evaluation and at 6-month intervals thereafter. The present report focuses on the results in 22 consecutive infants with syndromic synostosis who underwent initial surgery between 1991 and 1994. All but 4 children underwent initial cranial reconstruction at 6-18 months of age. Four patients had papilledema preoperatively which in each instance resolved postoperatively. During the follow-up period, 8 children manifested evidence of late intracranial hypertension at a median of 16.5 months after initial operation(s): 4 developed asymptomatic papilledema, 1 had progressive proptosis, and 3 had other subtle clinical signs of increased intracranial pressure (ICP). Further evaluation disclosed a Chiari 1 malformation in 2 children; 4 had a 'beaten copper' appearance on skull radiographs, and 4 underwent lumbar puncture, which in each case demonstrated an opening pressure above 20 cm H2O. Only 3 children exhibited symptoms from the ICP elevation. Six children with a head size less than or equal to the 25th percentile underwent a repeat cranial expansion; after the cranial vault expansion, one child who initially had slit-like ventricles developed ventriculomegaly and, because of persistent papilledema, underwent insertion of ventriculoperitoneal (VP) shunt. Two other patients with a head circumference above the 50th percentile and the development of moderate ventriculomegaly underwent VP shunt insertion alone. All children have had complete resolution of papilledema as well as other symptoms and signs of increased ICP without evidence of optic atrophy or neurological sequelae. This study indicates that the incidence of delayed, asymptomatic increases in ICP among children with complex craniosynostosis is higher than previously estimated. The pathophysiologic bases for this process are discussed. Because the detection of this problem at a presymptomatic stage should optimize the likelihood of a good functional outcome, we strongly recommend close ophthalmological and clinical follow-up as a part of the comprehensive care of all young children with complex craniosynostosis, even after a cosmetically successful cranial expansion.