title: Evaluation of patients with spontaneous subarachnoid hemorrhage and negative angiography.
abstract: OBJECTIVE
  The evaluation of patients with subarachnoid hemorrhage (SAH) with negative initial catheter-based angiography is a diagnostic challenge. Better diagnostic strategies based on hemorrhage patterns are needed.
  
  
  METHODS
  We retrospectively investigated the yield of focused history taking, magnetic resonance imaging of the brain and cervical spine, follow-up vascular imaging, laboratory investigations, and craniotomy for vessel exploration in 100 patients with SAH and negative initial catheter-based angiography.
  
  
  RESULTS
  The most common distribution of hemorrhage was in a "classic" aneurysmal pattern filling the basal cisterns or posterior fossa (44 patients). A cause was determined in 13 patients (13%), the most common of which was aneurysm (7 patients). Repeat angiography was the most useful diagnostic modality, detecting seven lesions. The yield of the second angiogram was best in patients with a classic hemorrhage pattern (10%) and worse in patients with a negative computed tomographic scan and positive lumbar puncture (0%). The most common reason that a lesion was not detected on initial angiography was aneurysmal thrombosis (five patients). Magnetic resonance imaging of the brain and cervical spine detected one cervical ependymoma. Factors that may contribute to SAH, such as antiplatelet agent use and drug use, were found in 13 patients (13%). Adjunctive laboratory studies alerted practitioners to modifiable risk factors.
  
  
  CONCLUSIONS
  These data suggest useful modifications to current diagnostic paradigms for patients with angiographically negative spontaneous SAH.
authors.affiliation: Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA.
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Little
authors.forename: Mark
authors.initials: M
authors.lastname: Garrett
authors.forename: Rasha
authors.initials: R
authors.lastname: Germain
authors.forename: Nabeel
authors.initials: N
authors.lastname: Farhataziz
authors.forename: Felipe C
authors.initials: FC
authors.lastname: Albuquerque
authors.forename: Cameron G
authors.initials: CG
authors.lastname: McDougall
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Zabramski
authors.forename: Peter
authors.initials: P
authors.lastname: Nakaji
authors.forename: Robert F
authors.initials: RF
authors.lastname: Spetzler
mesh_terms: D002533:Cerebral Angiography / Q000379:methods*; D005069:Evaluation Studies as Topic; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D012189:Retrospective Studies; D013129:Spinal Puncture / Q000379:methods; D013345:Subarachnoid Hemorrhage / Q000145:classification / Q000175:diagnosis* / Q000209:etiology; D014057:Tomography, X-Ray Computed / Q000379:methods