Giant cerebral arteriovenous malformation producing a noncommunicating hydrocephalus

The case of a woman with a large, mixed, cerebral arteriovenous malformation mainly involving the posterior fossa and producing a noncommunicating hypertensive hydrocephalus is reported. Relief of ventricular enlargement by means of a cerebrospinal fluid shunt unexpectedly resulted in stupor and Parinauds' syndrome. These complications were completely relieved by ligating the shunt. The vascular and mechanical factors involved in the production of hydrocephalus in this patient are discussed.