Orbital and nasal meningoencephaloceles secondary to chronic hydrocephalus: A rare cause of bilateral proptosis.

Introduction Orbital meningoencephalocele formation is primarily a result of congenital defects in the pediatric population and trauma of the anterior cranial fossa in adults. We present a unique case of nontraumatic nasal and orbital meningoencephaloceles presenting as bilateral proptosis with exotropia secondary to chronic hydrocephalus. Clinical presentation A 20-year-old male with a history of tuberous sclerosis, X-linked intellectual disability, and epilepsy presented to the emergency department with two days of nausea, emesis, seizures, and two months of progressive proptosis. Initial radiographs of the skull showed a "copper beaten" appearance, indicating chronically elevated intracranial pressure. Computed tomography imaging of the head demonstrated bilateral defects in the cribriform plate and anterior cranial fossa. Magnetic resonance imaging of the brain revealed triventricular hydrocephalus with meningoencephalocele extension into the nasal cavity and frontal horn herniation into the extraconal space of the orbits. The hydrocephalus was managed with ventriculoperitoneal shunt placement with rapid and complete resolution of the proptosis. Conclusion No reports have described bilateral proptosis as the presenting finding of orbital and nasal meningoencephaloceles in the absence of trauma or congenital defect. This case study demonstrates the management of meningoencephalocele formation secondary to chronic hydrocephalus.