title: Perimesencephalic nonaneurysmal subarachnoid hemorrhage: review of the literature.
abstract: OBJECTIVE
  A critical review of the literature on the incidence, presentation, diagnosis, and prognosis of perimesencephalic nonaneurysmal subarachnoid hemorrhage.
  
  
  METHODS
  Review of the relevant literature.
  
  
  CONCLUSIONS
  The importance of early computed tomography (< 3 d), anatomy of the perimesencephalic and neighboring cisterns, and adequate four-vessel angiography are discussed. Treatment strategies, including the avoidance of repeated angiographic studies and surgical exploration, are presented.
authors.affiliation: Department of Neurological Surgery, Neurological Institute of New York, Columbia-Presbyterian Medical Center, New York, USA.
authors.forename: T H
authors.initials: TH
authors.lastname: Schwartz
authors.forename: R A
authors.initials: RA
authors.lastname: Solomon
mesh_terms: D002533:Cerebral Angiography; D003937:Diagnosis, Differential; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery; D008636:Mesencephalon / Q000000981:diagnostic imaging / Q000601:surgery*; D011379:Prognosis; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D014057:Tomography, X-Ray Computed