[1] Med Univ S Carolina, Dept Neurol, Neurosci Intens Care Unit, Charleston, SC 29425 USA
[2] Med Univ S Carolina, Dept Neurosurg, Neurosci Intens Care Unit, Charleston, SC 29425 USA
[3] Johns Hopkins Univ, Sch Med, Dept Neurol Surg, Baltimore, MD USA
[4] Johns Hopkins Univ, Sch Med, Dept Anesthesiol Crit Care Med, Baltimore, MD USA
[5] Johns Hopkins Univ, Sch Med, Dept Neurol, Baltimore, MD 21205 USA