Dural arteriovenous fistula presenting with acute subdural haematoma showing impending cerebral herniation.

A dural arteriovenous fistula (DAVF) presenting with acute subdural haematoma (ASDH), which were not related to head injury, is rare. A 61-year-old woman was transported by ambulance because of deterioration of consciousness. On admission, she was comatose with anisocoria. Emergent CT demonstrated a severe midline shift associated with a left ASDH and an additional left occipital intracerebral haematoma, both of which had no continuity with each other. MRI showed flow void signs in the left occipital lobe. Because of the impending cerebral herniation, an emergent evacuation of the ASDH and external decompression was performed. Subsequent evaluation revealed a DAVF at the left occipital convexity near the confluence with retrograde leptomeningeal venous reflux and venous ectasia (Cognard type III DAVF). The patient underwent endovascular treatment for the DAVF involving transarterial embolisation using coils and N-butyl cyanoacrylate with complete obliteration. Her further clinical course was uneventful and discharged after cranioplasty.