title: Quadrigeminal perimesencephalic subarachnoid hemorrhage.
abstract: OBJECTIVE
  A variant of perimesencephalic subarachnoid hemorrhage (PSAH) has been described characterized by blood centered in the quadrigeminal cistern and limited to the superior vermian and perimesencephalic cisterns. Herein, three cases of quadrigeminal PSAH are presented.
  
  
  METHODS
  Medical records of all patients who underwent digital subtraction angiography for evaluation of non-traumatic SAH between July 2002 and April 2012 were reviewed. Patients with anterior circulation aneurysms were excluded. Two blinded reviewers identified admission noncontrast CT scans with pretruncal and quadrigeminal patterns of PSAH.
  
  
  RESULTS
  The total cohort included 106 patients: 53% (56/106) with one or more negative digital subtraction angiograms and 47% (50/106) with posterior circulation or posterior communicating artery aneurysms. Three patients with quadrigeminal PSAH were identified, two with nonaneurysmal SAH and one with a posterior circulation aneurysm. Seventeen patients (16%; 17/106) with pretruncal PSAH were identified, none of whom were found to have an aneurysm. The quadrigeminal pattern comprised 11% (2/19) of cases of pretruncal or quadrigeminal nonaneurysmal PSAH.
  
  
  CONCLUSIONS
  A small subset of patients with nonaneurysmal PSAH present with blood centered in the quadrigeminal cistern, and the etiology of this pattern may be similar to that of the classic pretruncal variant. However, patients with quadrigeminal PSAH must still undergo thorough vascular imaging, including at least two digital subtraction angiograms, to exclude a ruptured aneurysm.
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, Saint Louis, MO 63110, United States. Electronic address: wallacea@mir.wustl.edu.
authors.forename: Adam N
authors.initials: AN
authors.lastname: Wallace
authors.affiliation: Washington University School of Medicine, Saint Louis, MO, United States.
authors.forename: Ross
authors.initials: R
authors.lastname: Vyhmeister
authors.affiliation: Sharp Grossmont Hospital, San Diego, CA, United States.
authors.forename: Ryan
authors.initials: R
authors.lastname: Viets
authors.affiliation: Texas Radiology Associates, Plano, TX, United States.
authors.forename: Justin T
authors.initials: JT
authors.lastname: Whisenant
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, Saint Louis, MO 63110, United States.
authors.forename: Arindam R
authors.initials: AR
authors.lastname: Chatterjee
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, Saint Louis, MO 63110, United States.
authors.forename: Akash P
authors.initials: AP
authors.lastname: Kansagra
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, Saint Louis, MO 63110, United States.
authors.forename: DeWitte T
authors.initials: DT
authors.lastname: Cross
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, Saint Louis, MO 63110, United States.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Moran
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, Saint Louis, MO 63110, United States.
authors.forename: Colin P
authors.initials: CP
authors.lastname: Derdeyn
mesh_terms: D000328:Adult; D017542:Aneurysm, Ruptured / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000601:surgery*; D015901:Angiography, Digital Subtraction / Q000379:methods; D001921:Brain / Q000000981:diagnostic imaging; D002533:Cerebral Angiography / Q000379:methods; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000601:surgery*; D013346:Subarachnoid Space / Q000000981:diagnostic imaging
keywords: Aneurysm; Computed tomography angiography; Digital subtraction angiography; Nonaneurysmal subarachnoid hemorrhage; Perimesencephalic subarachnoid hemorrhage; Quadrigeminal perimesencephalic subarachnoid hemorrhage