Vestibular schwannoma causing normal pressure hydrocephalus.

Vestibular schwannoma is a common benign tumour that may cause local complications. However, vestibular schwannoma has a known association with communicating hydrocephalus presenting with symptoms of normal pressure hydrocephalus and requiring treatment by ventricular shunting or tumour resection. We report a 79-year-old woman who presented with subacute gait apraxia, cognitive impairment and urinary incontinence. CT and MR imaging identified a 20 mm vestibular schwannoma and communicating hydrocephalus; her cerebrospinal fluid (CSF) protein was elevated. Her symptoms improved following ventriculoperitoneal shunt insertion. The mechanism by which non-obstructing vestibular schwannoma causes hydrocephalus is unclear, but hyperproteinorrachia is probably important, likely by impeding CSF resorption.