title: Extracranial vertebral artery pseudoaneurysm presenting as subarachnoid hemorrhage.
abstract: OBJECTIVE
  True aneurysms of the extracranial vertebral artery are rare. The usual pathogenesis of aneurysms in this location is either penetrating or blunt trauma with resultant pseudoaneurysm formation. We report a postpartum patient with a presumed traumatic pseudoaneurysm of the extracranial vertebral artery presenting with subarachnoid hemorrhage.
  
  
  METHODS
  A 41-year-old woman had three episodes of neck stiffness 1 month after an uncomplicated vaginal delivery. The last episode, 3 days before admission, was accompanied by intense neck and head pain and paresthesias that extended into the left arm, thumb, and forefinger.
  
  
  RESULTS
  Lumbar puncture showed subarachnoid hemorrhage. Angiography revealed a left vertebral artery dissection from C6-7 to C3 with pseudoaneurysm at C5-6. Computed tomography demonstrated impingement of the C6 root at the foramen by this lesion. The lesion was successfully treated by balloon occlusion of the vertebral artery.
  
  
  CONCLUSIONS
  We present a patient with an extracranial vertebral pseudoaneurysm with subarachnoid hemorrhage and cervical root impingement. To our knowledge, this is the first case of such a lesion presenting as subarachnoid hemorrhage. The lesion was successfully treated using endovascular techniques.
authors.affiliation: Neurosurgical Service, Massachusetts General Hospital, Boston 02114.
authors.forename: S S
authors.initials: SS
authors.lastname: Kaplan
authors.forename: C S
authors.initials: CS
authors.lastname: Ogilvy
authors.forename: R
authors.initials: R
authors.lastname: Gonzalez
authors.forename: D
authors.initials: D
authors.lastname: Gress
authors.forename: J
authors.initials: J
authors.lastname: Pile-Spellman
mesh_terms: D000328:Adult; D000783:Aneurysm / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D011859:Radiography; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis*; D014711:Vertebral Artery