1 Division of Neurosciences Critical Care, Department of Anesthesiology and Critical Care Medicine; Department of Neurology; Department of Neurosurgery, Johns Hopkins University School of Medicine; and Department of Neurology, Johns Hopkins Bayview Medical Center, Baltimore, MD Division of Neurosciences Critical Care, Department of Anesthesiology and Critical Care Medicine; Department of Neurology; Department of Neurosurgery; Department of Radiology, Johns Hopkins University School of Medicine; and Department of Neurology, Johns Hopkins Bayview Medical Center, Baltimore, MD; Department of Neurology, Johns Hopkins University School of Medicine; and Department of Neurology, Johns Hopkins Bayview Medical Center, Baltimore, MD.