Delayed isolated tension intraventricular pneumocephalus after ventriculoperitoneal shunt

Objective and importance. - Delayed and isolated tension intraventricular pneumocephalus without air in the pericerebral subarachnoid spaces is an exceptional complication of a ventriculoperitoneal (VP) shunt. We purpose an explanation for the development of such delayed pneumocephalus. Clinical presentation. -A 14-year-old boy developed headaches and right-side hearing loss three months after surgical resection of a cerebellar medulloblastoma and insertion of a VP shunt. CT-scan showed isolated intraventricular pneumocephalus without air in the pericerebral subarachnoid spaces. A petrous bone defect was discovered and surgically repaired with clinical and radiographic resolution of pneumocephalus. Conclusion. - We presume that the brain tissue plugging the bony defect retracted following the placement of the shunt and eventually there was rupture through the pia-mater into the lateral ventricle. This could explain why isolated intraventricular occurred, as opposed to air in the subarachnoid spaces.