DEFINITION:
Delayed Cerebral Ischemia:
Focal (hemiparesis, aphasia, hemianopia, or neglect) or global (2 points decrease on GCS) neurological impairment lasting for at least 1 hour and/or cerebral infarction, which:
▪ Is not apparent immediately after aneurysm occlusion
▪ Is attributable to ischemia
▪ Is not attributed to other causes (i.e. surgical complication, metabolic derangements) after appropriate clinical, imaging, and laboratory evaluation
Cerebral infarction:
Presence of cerebral infarction on CT or MR scan of the brain within 6 weeks after SAH, or on the latest CT or MR scan made before death within 6 weeks, or proven at autopsy; that is:
▪ Not present on the CT or MR scan between 24 and 48 hours after early aneurysm occlusion
▪ Not attributable to other causes such as surgical clipping or endovascular treatment
▪ Not due to a nonischemic lucency related to a ventricular catheter, intraparenchymal hematoma, or brain retraction injury
Reference:
Francoeur, Charles L. and Stephan A. Mayer. “Management Of Delayed Cerebral Ischemia After Subarachnoid Hemorrhage”. Critical Care 20.1 (2016): n. pag. Web.