The use of clinical and routine imaging data to differentiate between aneurysmal and nonaneurysmal subarachnoid hemorrhage prior to angiography

Object. In this study, the authors' goal was to minimize false-negative results in the detection of ruptured cerebral aneurysms. Methods. The authors retrospectively reviewed the clinical and radiological information in consecutive adult patients admitted with acute subarachnoid hemorrhage (SAH) to their hospital between January 1, 2002, and January 1, 2008. Patients were grouped based on the presence or absence of a ruptured aneurysm, which was detected by catheter angiography. Multivariate logistic regression analysis was used to identify factors predicting detection of aneurysmal rupture by angiography. Results. The authors identified 199 patients (121 women [61%]). A ruptured aneurysm was detected in 167 patients (84%). In multivariate analysis, loss of consciousness at the onset of SAH was a strong predictive factor associated with detection of a ruptured aneurysm on subsequent angiography (OR > 100, p = 0.0002). The positive predictive value of loss of consciousness at the onset of SAH for detection of a ruptured aneurysm was 100%. Conclusions. Loss of consciousness at the onset of SAH is highly predictive of aneurysm rupture. A negative CT angiography study in these patients may be a false result, and a high-quality catheter angiography should be performed. (DOI:10.3171/2010.4.JNS091932)