Dural arteriovenous fistulas are abnormal connections of dural artery to dural veins or venous sinuses originating from within the dural leaflets. They are usually located near or within the wall of a dural venous sinus that is frequently obstructed or stenosed. The dural fistula sac is contained within the dural leaflets, and drainage can be via a dural sinus or retrograde through cortical veins (leptomeningeal drainage).

Dural arteriovenous malformations in the anterior cranial fossa are rare and are especially prone to haemorrhage ¹⁾. . Dural arteriovenous fistulas can occur at any dural sinus but are found most frequently at the cavernous or transverse sinus.

Non-traumatic subdural hematoma (SDH) caused by dural arteriovenous fistula (DAVF) is rare and is usually accompanied by intracerebral hemorrhage (ICH) and/or subarachnoid hemorrhage (SAH).

Dural arteriovenous fistula (AVF) presenting with subdural hematoma is relatively rare.

A 56-year-old man presented with disturbance of consciousness. Computed tomography demonstrated a right ASDH and a small right occipital subcortical hematoma. Cerebral angiography showed a dural AVF on the occipital convexity draining into the cortical veins. Emergent endovascular embolization was immediately performed and the shunt flow disappeared. Hematoma removal and external decompression were safely conducted. Combined therapy successfully recovered the patient's consciousness level. This rare case of dural AVF presenting with ASDH was treated with combined treatments of endovascular and open surgery ²⁾.

A male patient who showed pure acute subdural hematoma aSDH and was diagnosed as having dural arteriovenous fistula AVF on the convexity near the superior sagittal sinus (SSS), based on angiographic findings. A 27-year-old man was admitted to the hospital due to headache with acute onset. The patient did not have a history of head trauma or injury. Head CT showed an abnormal high-density area on the surface of the cerebral hemisphere on the left side, indicating acute SDH. Angiography during the arterial phase demonstrated that an abnormal artery originating from the left occipital artery was connected with a dural vein and a diploic vein on the convexity near the SSS. They concude that a dural AVF existed at this area, and that the dural AVF had caused the acute SDH. Dural AVF/AVM which causes non-traumatic SDH is usually accompanied by intracerebral hemorrhage (ICH) and/or subarachnoid hemorrhage (SAH). In contrast, non-traumatic dural AVF/AVM presenting with pure SDH is rare, and this patient represents such a rare case. We should consider dural AVF/AVM and perform angiography if necessary when we encounter a patient showing non-traumatic SDH without ICH and/or SAH ³⁾.

A patient presented with a sudden-onset severe headache, and was diagnosed with acute SDH by computed tomography. Cerebral angiography showed a DAVF on the left convexity adjacent to the superior sagittal sinus (SSS). This DAVF drained to the SSS and to the pterygoid venous plexus via the left middle fossa without retrograde flow (Type I according to the Cognard classification). The SDH was thickest at the lower convexity, which suggested that the draining vein of the DAVF was responsible for the bleeding.

The SDH slowly progressed for two weeks. The DAVF was successfully treated with transarterial embolization using N-butyl 2-cyanoacrylate. The SDH was resolved via burr-hole drainage surgery.

This is the first reported case of DAVF that caused non-traumatic progression to SDH. As DAVF can be the cause of acute and chronic SDH, cerebral angiography is recommended for non-traumatic acute SDH as well as for intractable chronic SDH ⁴⁾.