Vertebrobasilar Dolichoectasia Causing Symptomatic Hydrocephalus Due to Third Ventricular Compression

Vertebrobasilar dolichoectasia sometimes presents with symptoms related to mass effect like cranial nerve palsies, or with ischemia or hemorrhage. Symptomatic hydrocephalus as a complication of vertebrobasilar dolichoectasia is extremely uncommon. Furthermore, there are few cases of vertebrobasilar dolichoectasia, in which cerebrospinal fluid flow disorder mechanisms are clearly demonstrated in neuroimaging findings. Here, we describe a patient with vertebrobasilar dolichoectasia who presented with symptomatic hydrocephalus due to direct compression against the third ventricle, which was immediately relieved by ventriculoperitoneal shunt. This patient exhibited a progressive clinical course of acute hydrocephalus; however, a subclinical ventricular dilatation may have been present before the onset. Therefore, a careful follow-up is warranted to treat symptomatic hydrocephalus that may develop in patients with vertebrobasilar dolichoectasia.