Early cerebral infarction as a risk factor for poor outcome after aneurysmal subarachnoid haemorrhage

Background and purpose: After aneurysmal subarachnoid haemorrhage, severity of bleeding, and occurrence of rebleeding and cerebral infarcts are the main factors predicting outcome. We investigated predictive risk factors for both early and late cerebral infarcts, and whether time of appearance of infarct is associated with outcome. Methods: Previous diseases as well as clinical, laboratory and radiological variables including serial CT scans were recorded for 173 patients admitted within 48 h after bleeding and with ruptured aneurysm occlusion by open surgery within 60 h. Factors predicting occurrence of cerebral infarct and poor outcome at 3 months according to the Glasgow Outcome Scale were tested using multiple logistic regression. Results: Of several potential predictors, poor outcome was independently predicted by patient age, rebleeding, intraventricular haemorrhage, intracerebral haematoma, delayed cerebral ischaemia with fixed symptoms and early new ischaemic lesion on CT scan appearing on the 1st post-operative morning (P < 0.01 for each factor). After adjustment for confounding factors, occurrence of early infarct (odds ratio 12.5; 95% confidence interval 3.2-48.7; P < 0.01), both early and late infarct (6.6; 1.1-40.4; P < 0.05), and late infarct only (2.4; 0.6-9.1) increased risk for poor outcome. Adjusted independent significant risk factors for early infarction were duration of artery occlusion during surgery (1.4/min; 1.1-1.7, P < 0.01) and admission plasma glucose level (1.3 per mM; 1.0-1.6, P < 0.05) and for late infarction amount of subarachnoid blood (4.5; 1.3-14.9, P < 0.05). Conclusion: Early infarction after surgical aneurysm occlusion seems to have different risk factors and worse prognosis than late infarct which is mostly associated with delayed cerebral ischaemia.