Posterior fossa hemorrhage caused by dural arteriovenous fistula: case reports.

Background: Relatively few reports are available on dural arteriovenous fistulas (AVFs) accompanied by posterior fossa hemorrhage. We now report upon two such cases and discuss the differential diagnosis and imaging findings.

Case Description: A 36-year-old man was admitted after experiencing sudden headache. Computerized tomography (CT) showed vermian and fourth ventricular hematoma, and magnetic resonance imaging (MRI) revealed an abnormal signal void. Angiography demonstrated a dural AVF in the region of foramen magnum. The second case, a 57-year-old man, was also admitted for the evaluation of headache. CT scan revealed tentorial subdural, subarachnoid and vermian hemorrhage. MRI showed vermian hematoma and an abnormal signal void below the tentorium. Angiography demonstrated a dural AVF in the tentorium. The first case underwent transarterial embolization, after which the dural AVF disappeared completely. The second case underwent craniotomy immediately after failure of endovascular therapy. Postoperative angiography demonstrated no remaining dural AVF.

Conclusions: Dural AVF should be considered as a causative lesion in cases with posterior fossa hemorrhage with no other definitive cause.