From: Management of delayed cerebral ischemia after subarachnoid hemorrhage
Delayed cerebral ischemia |
Focal (hemiparesis, aphasia, hemianopia, or neglect) or global (2 points decrease on GCS) neurological impairment lasting for at least 1Â 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 6Â weeks after SAH, or on the latest CT or MR scan made before death within 6Â 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 |