1. Patients must be evaluable for WFNS grade prior to the endovascular coiling procedure. Patients who cannot be assessed for WFNS post procedure due to a requirement for uninterrupted sedation (e.g., for high or unstable intracranial pressure [ICP]) may be included in the study provided that a CT scan is performed at least 12 hours post-procedure, but prior to randomization, ruling out any large procedure-related infarct.