Vertebrobasilar artery ectasia presenting as hydrocephalus.

Symptomatic hydrocephalus in association with basilar artery ectasia is a rare occurrence. We report an 81-year-old woman with progressive dementia, gait disturbance, and sphincter incontinence. Brain computed tomography (CT) and magnetic resonance imaging (MRI) scans showed obstructive hydrocephalus with compression of the fourth ventricle by a large ectatic basilar artery. After ventriculoperitoneal shunting, the patient showed rapid resolution of symptoms. This case illustrates that ventricular obstruction due to basilar artery ectasia can mimic the classical triad of normal pressure hydrocephalus.