Predictors of cerebral infarction in aneurysmal subarachnoid hemorrhage

Background - Clinical and radiologic predictors of cerebral infarction occurrence and location after aneurysmal subarachnoid hemorrhage have been seldom studied. Methods - We evaluated all patients admitted to our hospital with aneurysmal subarachnoid hemorrhage between 1998 and 2000. Cerebral infarction was defined as a new hypodensity located in a vascular distribution on computed tomography (CT) scan. Results - Fifty-seven of 143 patients (40%) developed a cerebral infarction. On univariate analysis, occurrence of cerebral infarction was associated with a worse World Federation of Neurological Surgeons grade (P=0.01), use of ventriculostomy catheter (P=0.01), preoperative vasospasm (P=0.03), surgical clipping (P=0.02), symptomatic vasospasm (P<0.01), and vasospasm on transcranial Doppler ultrasonography (TCD) or repeat angiogram (P<0.01). On multivariable analysis, only presence of symptoms ascribed to vasospasm (P<0.01) and evidence of vasospasm on TCD or angiogram predicted cerebral infarction (P<0.01). TCD and angiogram agreed on the diagnosis of vasospasm in 73% of cases (95% CI, 63% to 81%), but the diagnostic accuracy of this combination of tests was suboptimal for the prediction of cerebral infarction occurrence (sensitivity, 0.72; specificity, 0.68; positive predictive value, 0.67; negative predictive value, 0.72). Location of the cerebral infarction on delayed CT was predicted by neurological symptoms in 74%, by aneurysm location in 77%, and by angiographic vasospasm in 67%. Conclusions - Evidence of vasospasm on TCD and angiogram is predictive of cerebral infarction on CT scan but sensitivity and specificity are suboptimal. Cerebral infarction location cannot be predicted in one quarter to one third of patients by any of the studied clinical or radiological variables.