Abstract
BACKGROUND: Subarachnoid hemorrhage (SAH) is most commonly caused by a ruptured vascular lesion. A significant number of patients presenting with SAH have no identifiable cause despite extensive cerebrovascular imaging at presentation. Significant neurological morbidity or mortality can result from misdiagnosis of aneurysm. OBJECTIVE: To generate a model to assist in predicting the risk of aneurysm in this patient population. METHODS: We conducted a retrospective study of all patients aged ≥18 yr admitted to a single center from March 2008 to March 2018 with nontraumatic SAH (n = 550). Patient information was compared between those with and without aneurysm to identify potential predictors. Odds ratios obtained from a logistic regression model were converted into scores which were summed and tested for predictive ability. RESULTS: Female sex, higher modified Fisher or Hijdra score, nonperimesencephalic location, presence of intracerebral hemorrhage, World Federation of Neurosurgical Societies (WFNS) score ≥3, need for cerebrospinal fluid diversion on admission, and history of tobacco use were all entered into multivariable analysis. Greater modified Fisher, greater Hijdra score, WFNS ≥3, and hydrocephalus present on admission were significantly associated with the presence of an aneurysm. A model based on the Hijdra score and SAH location was generated and validated. CONCLUSION: We show for the first time that the Hijdra score, in addition to other factors, may assist in identifying patients at risk for aneurysm on cerebrovascular imaging. A simple scoring tool based on patient sex, SAH location, and SAH burden can assist in predicting the presence of an aneurysm in patients with nontraumatic SAH.