1 Department of Anesthesiology and Critical Care Medicine, Department of Neurology, and Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD; Department of Anesthesiology and Department of Physical Medicine and Rehabilitation, Uniformed Services University of the Health Sciences, Bethesda, MD. Electronic address: scohen40@jhmi.edu.
2 Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN.