Intraventricular hemorrhage from a dural arteriovenous fistula

Noncontrast head CT showing acute intraventricular and subarachnoid hemorrhage (A) in the premedullary cistern (arrow) and foramen magnum (dashed arrow) subsequently determined to be caused by an upper cervical dural arteriovenous fistula. Reflux of cisternal blood through the foramina of Luschka and Magendie result in intraventricular blood (asterisks) in the fourth ventricle (B) and third ventricle (C).