Chiari malformation in nonsyndromal single craniosynostosis—Much Ado about Nothing?

Abstract

The significance of Chiari malformation in nonsyndromal-isolated craniosynostosis is still not well documented. Hence, in the present study we investigated the incidence of Chiari malformation in a larger series of patients with nonsyndromic-isolated single-suture craniosynostosis over a 9-year period using preoperative magnetic resonance imaging (MRI). Of 215 children who had undergone surgery for nonsyndromic-isolated craniosynostosis, 89 cases (41.4 %) had MRI prior to surgery. All MRIs were screened for Chiari malformation. Only one patient (1.1 %) with isolated lambdoid synostosis showed Chiari malformation preoperatively, which was defined as a cerebellar tonsillar descent greater than 5 mm below the foramen magnum. However, no clinical symptoms were associated with Chiari malformation in this patient. As Chiari malformation is more likely to be associated with syndromic craniosynostosis, nonsyndromic bilateral coronal synostosis, or synostosis of the lambdoid suture, a general use of MRI as a screening tool for Chiari malformation should not be recommended for patients with nonsyndromic-isolated craniosynostosis who lack clinical symptoms.