title: Definition of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage as an outcome event in clinical trials and observational studies: proposal of a multidisciplinary research group.
abstract: OBJECTIVE
  In clinical trials and observational studies there is considerable inconsistency in the use of definitions to describe delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage. A major cause for this inconsistency is the combining of radiographic evidence of vasospasm with clinical features of cerebral ischemia, although multiple factors may contribute to DCI. The second issue is the variability and overlap of terms used to describe each phenomenon. This makes comparisons among studies difficult.
  
  
  METHODS
  An international ad hoc panel of experts involved in subarachnoid hemorrhage research developed and proposed a definition of DCI to be used as an outcome measure in clinical trials and observational studies. We used a consensus-building approach.
  
  
  RESULTS
  It is proposed that in observational studies and clinical trials aiming to investigate strategies to prevent DCI, the 2 main outcome measures should be: (1) cerebral infarction identified on CT or MRI or proven at autopsy, after exclusion of procedure-related infarctions; and (2) functional outcome. Secondary outcome measure should be clinical deterioration caused by DCI, after exclusion of other potential causes of clinical deterioration. Vasospasm on angiography or transcranial Doppler can also be used as an outcome measure to investigate proof of concept but should be interpreted in conjunction with DCI or functional outcome.
  
  
  CONCLUSIONS
  The proposed measures reflect the most relevant morphological and clinical features of DCI without regard to pathogenesis to be used as an outcome measure in clinical trials and observational studies.
authors.affiliation: Department of Neurology, Academic Medical Center, Amsterdam, the Netherlands. m.d.vergouwen@amc.uva.nl
authors.forename: Mervyn D I
authors.initials: MD
authors.lastname: Vergouwen
authors.forename: Marinus
authors.initials: M
authors.lastname: Vermeulen
authors.forename: Jan
authors.initials: J
authors.lastname: van Gijn
authors.forename: Gabriel J E
authors.initials: GJ
authors.lastname: Rinkel
authors.forename: Eelco F
authors.initials: EF
authors.lastname: Wijdicks
authors.forename: J Paul
authors.initials: JP
authors.lastname: Muizelaar
authors.forename: A David
authors.initials: AD
authors.lastname: Mendelow
authors.forename: Seppo
authors.initials: S
authors.lastname: Juvela
authors.forename: Howard
authors.initials: H
authors.lastname: Yonas
authors.forename: Karel G
authors.initials: KG
authors.lastname: Terbrugge
authors.forename: R Loch
authors.initials: RL
authors.lastname: Macdonald
authors.forename: Michael N
authors.initials: MN
authors.lastname: Diringer
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Broderick
authors.forename: Jens P
authors.initials: JP
authors.lastname: Dreier
authors.forename: Yvo B W E M
authors.initials: YB
authors.lastname: Roos
mesh_terms: D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000209:etiology*; D002986:Clinical Trials as Topic; D006801:Humans; D017063:Outcome Assessment, Health Care; D011859:Radiography; D013345:Subarachnoid Hemorrhage / Q000150:complications* / Q000000981:diagnostic imaging; D016896:Treatment Outcome