Hydrocephalus and Chiari malformation pathophysiology in FGFR2-related faciocraniosynostosis: A review

Patients with syndromic faciocraniosynostosis due to the mutation of the fibroblast growth factor receptor (FGFR) 2 gene present premature fusion of the coronal sutures and of the cranial base synchondrosis. Cerebrospinal fluid (CSF) circulation disorders and cerebellar tonsil prolapse are frequent findings in faciocraniosynostosis.

We reviewed the medical literature on the pathophysiological mechanisms of CSF disorders such as hydrocephalus and of cerebellar tonsil prolapse in FGFR2-related faciocraniosynostosis.

Different pathophysiological theories have been proposed, but none elucidated all the symptoms present in Apert, Crouzon and Pfeiffer syndromes. The first theory that addressed CSF circulation disruption was the constrictive theory (cephalocranial disproportion): cerebellum and brain stem are constricted by the small volume of the posterior fossa. The second theory proposed venous hyperpressure due to jugular foramens stenosis. The most recent theory proposed a pressure differential between CSF in the posterior fossa and in the vertebral canal, due to foramen magnum stenosis.