Delayed otogenic pneumocephalus complicating ventriculoperitoneal shunt.

Tension pneumocephalus complicating ventriculoperitoneal shunt is extremely rare. We report an elderly male who developed delayed tension pneumocephalus 12 months after ventriculoperitoneal shunt for hydrocephalus complicating aneurysmal subarachnoid hemorrhage. Fine-cut reformatted computer tomography scan revealed a large pneumatocele on the petrous apex associated with tegmen tympani defect. The shunt valve pressure was temporarily raised from 120 mm H 2 O to 200 mm H 2 O, and the patient underwent successful subtemporal extradural repair of the bony defect in the temporal bone. Although extremely rare, otogenic tension pneumocephalus is a potentially life-threatening condition, and urgent surgical repair of the bony defect in the temporal bone reduces the risk of both the morbidity and mortality.