Pneumocephalus associated with aqueductal stenosis: three-dimensional computed tomographic demonstration of skull-base defects

Ventriculoperitoneal (VP) shunt placement in patients with aqueductal stenosis has recently been reported as a cause of pneumocephalus. We report on a patient with pneumocephalus associated with aqueductal stenosis treated by VP shunting. A 29-year-old woman who had undergone a shunt operation for aqueductal stenosis 7 years previously sustained a whiplash injury in a minor traffic accident. Computed tomography (CT) revealed massive subdural pneumocephalus, and three-dimensional reconstructions of CT images clearly demonstrated defects in the skull base overlying the ethmoid sinuses. Both endoscopic III ventriculostomy and placement of external ventricular drainage were performed. After temporary external ventricular drainage for 7 days, a VP shunt was placed using a programmable valve system. The patient became free of symptoms and rhinorrhea ceased. Three-dimensionally reconstructed CT images were useful in detecting the extent of the patient’s skull base defect. III Ventriculostomy was not effective in this case. Direct closure of the skull base by craniotomy was not necessary, and a programmable valve system was effective in preventing recurrence of either pneumocephalus or rhinorrhea.