title: An analysis of 88 patients with diffuse and "benign" perimesencephalic subarachnoid hemorrhage.
abstract: OBJECTIVE
  Perimesencephalic subarachnoid hemorrhage (PMSAH) was previously defined as a variant of subarachnoid hemorrhage (SAH) associated with a relatively benign clinical presentation and better outcomes than aneurysmal SAH. However, several prior studies have shown complications associated with PMSAH including vasospasm and hydrocephalus, and the need for follow-up imaging. We therefore reviewed our experience to further characterize the clinical consequences of PMSAH.
  
  
  METHODS
  Eighty-eight consecutive patients who sustained spontaneous intracranial SAH and whose cerebral angiograms did not show any obvious source for SAH were retrospectively studied to characterize their prognosis and outcome based on SAH pattern. Glasgow Coma Scale and Hunt-Hess scores on admission, the incidence of vasospasm or hydrocephalus, the need for an external ventricular drain, and shunt dependence, along with Glasgow outcome score (GOS) at discharge and follow-up, were used to draw comparisons between perimesencephalic and diffuse SAH patient populations.
  
  
  RESULTS
  Patients with perimesencephalic SAH differed statistically (p < 0.05) from patients with diffuse SAH in regard to age, Hunt-Hess score on presentation, hospital length of stay, GOS at discharge, and incidence of hydrocephalus, angiographic vasospasm, and clinical vasospasm.
  
  
  CONCLUSIONS
  Our data demonstrate that although the patients with perimesencephalic SAH fared better than those with diffuse SAH, their outcomes were worse than those of similar patients with PMSAH who have been previously reported in the literature.
authors.affiliation: Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana, United States.
authors.forename: Neal B
authors.initials: NB
authors.lastname: Patel
authors.affiliation: Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana, United States.
authors.forename: Amrita D
authors.initials: AD
authors.lastname: Patel
authors.affiliation: Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana, United States.
authors.forename: Jared
authors.initials: J
authors.lastname: Wilkinson
authors.affiliation: Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana, United States.
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Gianaris
authors.affiliation: Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana, United States.
authors.forename: Troy D
authors.initials: TD
authors.lastname: Payner
authors.affiliation: Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana, United States.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Leipzig
authors.affiliation: Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana, United States.
authors.forename: Shaheryar
authors.initials: S
authors.lastname: Ansari
authors.affiliation: Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana, United States.
authors.forename: Aaron A
authors.initials: AA
authors.lastname: Cohen-Gadol
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002533:Cerebral Angiography; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000000981:diagnostic imaging / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D013345:Subarachnoid Hemorrhage / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery; D020301:Vasospasm, Intracranial / Q000000981:diagnostic imaging / Q000209:etiology*