Many significant advances in the understanding of aSAH-induced vasospasm and DCI have been made since Connolly et al Management of Aneurysmal Subarachnoid Hemorrhage 1723 publication of the previous version of these guidelines, which focused on prevention with oral nimodipine and maintenance of euvolemia, as well as treatment with triple-H therapy (hemodynamic augmentation therapy) and/or endovascular therapy with vasodilators and angioplasty balloons. First, the case for nimodipine is even stronger, with a recent compre- hensive meta-analysis confirming improved neurological out- comes by preventing processes other than large-vessel nar- rowing.209,210 Although there have been sparse new important data on the lack of benefit for prophylactic hypervolemia compared with maintenance of euvolemia, new data show that both prophylactic angioplasty of the basal cerebral arteries and antiplatelet prophylaxis are ineffective in reduc- ing morbidity.211 213 Similarly, the only supportive data for the use of lumbar drainage come from a single case-control although there is ongoing investigation on the value of this intervention to reduce arterial spasm and DCI.214 The data are a bit better for intrathecal thrombolytic infusions, with a recent meta-analysis of 5 randomized, controlled trials suggesting a benefit despite some method- ological weaknesses.215,216 There are also emerging data for several novel methods to reduce the incidence and ischemic consequences of aSAH-induced vasospasm. These new ap- proaches are based on robust experimental data that indicate a critical role for endothelial dysfunction, particularly at the Several recent clinical trials have investigated the utility of statins, endothelin-1 antagonists, and magnesium sulfate.218 Statin agents have been studied in several small, single-center randomized trials with variable results. Although a recent meta-analysis reported no evidence for clinical benefit,219 a larger phase 3 trial (SimvasTatin in Aneurysmal Subarach- noid Hemorrhage [STASH]) is in progress. 