title: Dural arteriovenous fistula presenting as an acute subdural hemorrhage that subsequently progressed to a chronic subdural hemorrhage: case report.
abstract: OBJECTIVE
  Non-traumatic subdural hemorrhage (SDH) caused by dural arteriovenous fistula (DAVF) is rare and is usually accompanied by intracerebral hemorrhage (ICH) and/or subarachnoid hemorrhage (SAH). This report describes a very rare case of DAVF that caused non-traumatic acute SDH without ICH or SAH, which subsequently progressed into chronic SDH.
  
  
  METHODS
  The 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.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Division of Endovascular Neurosurgery, Stroke Center, International Medical Center, Saitama Medical University, Hidaka, Saitama, Japan. skohyama@saitama-med.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Kohyama
authors.forename: S
authors.initials: S
authors.lastname: Ishihara
authors.forename: F
authors.initials: F
authors.lastname: Yamane
authors.forename: R
authors.initials: R
authors.lastname: Kanazawa
authors.forename: H
authors.initials: H
authors.lastname: Ishihara
mesh_terms: D000208:Acute Disease; D020785:Central Nervous System Vascular Malformations / Q000150:complications* / Q000175:diagnosis* / Q000628:therapy; D002533:Cerebral Angiography; D002908:Chronic Disease; D018450:Disease Progression; D004621:Embolization, Therapeutic; D006408:Hematoma, Subdural / Q000175:diagnosis* / Q000209:etiology* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures