Background: Cerebral infarction is a sequela of vasospasm. Other etiologies for infarction after subarachnoid hemorrhage (SAH), however, have not been well-studied. To determine the incidence and etiologies for infarction after SAH, we reviewed the head CT scans of all SAH patients at our center from 1993-2000.
Methods: From 1993-2000, 679 consecutive patients were admitted with SAH, of which 619 patients underwent surgical or endovascular treatment. Two reviewers examined the head CT scans of all 619 patients for new infarct. Clinical outcome was collected from a prospective database.
Findings: 505 patients were treated with surgical clipping; 114 with endovascular coiling. There were CT findings of new infarct in 189 patients (30%): 140 in the surgical group (28%) and 49 in the endovascular group (43%). The etiologies for infarct in the surgical group were vasospasm 79 (15%), perforator occlusion 40 (8%), large vessel occlusion 14 (3%), elevated intracranial pressure 4 (1%), thromboembolism 2 (0.4%), and systemic hypotension 1 (0.2%). Infarcts in the endovascular group were due to vasospasm 20 (18%), thromboembolism 12 (11%), large vessel occlusion/dissection 9 (8%), elevated intracranial pressure 4 (4%), perforator occlusion 3 (3%), and systemic hypotension 1 (1%). Hunt Hess Grade (P < 0.001), Fisher Score (P < 0.0001), and MGH Grade (P < 0.001) were significantly associated with CT-demonstrated infarct. There was no significant difference in incidence of CT-infarcts when the period 1993-1996 was compared to 1997-2000.
Conclusions: Despite advances in the treatment of SAH, there is still a significant incidence of associated radiographic infarcts. Hunt Hess Grade, Fisher Score, and MGH Grade were significantly associated with CT-demonstrated infarct.