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. Clazosentan, an endothelin-1 receptor antagonist, had been shown to be associated with a dose-dependent reduction in the incidence of angiographic vasospasm in a phase IIb trial (Clazosentan to Overcome Neurological iSChemia and Infarct OccUrring after Subarachnoid hemorrhage [CONSCIOUS-1]).220 A ben- efit for clinical outcomes was not initially apparent but then was judged present when a stricter definition of vasospasm- related stroke was used. However, a subsequent trial (CONSCIOUS-2) that tested the drug in patients treated with aneurysm clipping found no improvement in clinical outcome in the clazosentan group.221 A similar study in patients treated with coiling (CONSCIOUS-3) was then stopped before com- pletion. Magnesium sulfate has been studied in several pilot trials. Although there is some suggestion of reduction in delayed ischemic deficits associated with magnesium infusion, a benefit has not been conclusively shown in a meta-analysis.222 A phase 3 trial (Intravenous Magnesium sulfate for Aneurysmal Subarachnoid Hemorrhage [IMASH]) did not support any clin- ical benefit from magnesium infusion over placebo in aSAH.223 A larger randomized trial is under way. With regard to the diagnosis of DCI, which can often be problematic, it is increasingly clear that although serial neurological examinations are important, they are of limited sensitivity in patients with poor clinical grade. Therefore, the diagnostic approach needs to be tailored to the clinical situation. Various diagnostic tools are commonly used to identify (1) arterial narrowing and/or (2) perfusion abnormal- ities or reduced brain oxygenation. These different tools have advantages and disadvantages. 