Abstract 3456: Incidence of Vasospasm and Outcomes in Angiography-negative Perimesencephalic Subarachnoid Hemorrhage with and without Ventricular Extension

Abstract

Background: Angiography negative perimesencephalic subarachnoid hemorrhage (SAH) is considered a relatively benign entity compared to aneurysmal SAH. However, some patients with angiography negative perimesencephalic subarachnoid hemorrhage with extension of hemorrhage beyond the perimesencephalic area are at increased risk for vasospasm. Here we present a series of 21 patients with angiography negative perimesencephalic pattern of SAH both with and without ventricular extension and describe their incidence of vasospasm and clinical outcomes. Methods: Retrospective chart review was performed among patients who underwent invasive angiography from 8/2007-6/2010. Inclusion criteria were presenting clinical symptoms typical of SAH, computed tomography (CT) evidence of perimesencephalic SAH with or without ventricular extension, no recent trauma or stroke, and cerebral angiography negative for aneurysm or arteriovenous malformation. 21 patients, 8 men and 13 women, with a mean age of 55.1 years met these criteria. The presenting CTs were examined and a modified Fisher Grade assigned. The patients’ clinical course was reviewed for incidence and treatment of vasospasm. The patients’ discharge summaries were evaluated and each patient given a modified Rankin Scale score. Results: The modified Fisher Scale score derived from the presenting CT was 1 for 29% (n=6), 2 for 5% (n=1), 3 for 19% (n=4), and 4 for 47% (n=10) of the patients. Amongst the 52% (n=11) of patients with intraventricular hemorrhage as defined by a modified Fisher Scale score of 2 or 4, 24% (n=5) developed angiographical evidence of vasospasm. 10% (n=2) of the patients required intra-arterial verapamil. 90% (n=9) of patients without intraventricular extension had good outcomes at discharge as defined by modified Rankin Scale score less than or equal to 2, while only 36% (n=4) of patients with angiography negative SAH with intraventricular extension had good outcomes. Conclusions: Although angiography negative perimesencephalic SAH is considered to have less associated morbidity and mortality than aneurysmal perimesencephalic SAH, patients with extension of hemorrhage into the ventricles are at increased risk for vasospasm and poor functional outcomes.