title: Perimesencephalic nonaneurysmal subarachnoid hemorrhage caused by jugular venous occlusion: case report.
abstract: OBJECTIVE
  The cause of perimesencephalic nonaneurysmal subarachnoid hemorrhage remains unknown. We describe a patient in whom jugular venous occlusion preceded the occurrence of perimesencephalic nonaneurysmal subarachnoid hemorrhage. This finding supports the theory that the source of the hemorrhage is venous in origin.
  
  
  METHODS
  A 25-year-old man presented with sudden onset of headache after his head was held in a headlock during a playful fight 48 hours before the ictus. His computed tomographic (CT) scan on admission demonstrated a perimesencephalic pattern of subarachnoid hemorrhage. CT angiography excluded the presence of an underlying aneurysm or vascular malformation but showed bilateral jugular venous obstruction with hematoma surrounding the right internal jugular vein. Magnetic resonance imaging and a 4-vessel cerebral angiogram confirmed the CT angiographic findings.
  
  
  METHODS
  The patient was observed as an inpatient and had no complication of his hemorrhage. Follow-up at 5 months with CT angiography showed resolution of his neck hematoma and reopening of his internal jugular veins.
  
  
  CONCLUSIONS
  The presence of acute jugular venous occlusion as a cause of perimesencephalic nonaneurysmal subarachnoid hemorrhage supports a venous origin of hemorrhage.
authors.affiliation: Department of Neurosurgery, Southern General Hospital, Glasgow, Scotland. rsangra@doctors.org.uk
authors.forename: Meharpal S
authors.initials: MS
authors.lastname: Sangra
authors.forename: Evelyn
authors.initials: E
authors.lastname: Teasdale
authors.forename: Mohammed A
authors.initials: MA
authors.lastname: Siddiqui
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Lindsay
mesh_terms: D000328:Adult; D000792:Angiography / Q000379:methods*; D006801:Humans; D002532:Intracranial Aneurysm / Q000209:etiology; D007601:Jugular Veins / Q000000981:diagnostic imaging*; D008297:Male; D008636:Mesencephalon / Q000098:blood supply / Q000000981:diagnostic imaging*; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging* / Q000209:etiology*; D014652:Vascular Diseases / Q000150:complications* / Q000000981:diagnostic imaging*