[1] Mayo Clin, Coll Med Rochester, Dept Neurol, Rochester, MN 55905 USA
[2] Mayo Clin, Coll Med Rochester, Dept Ophthalmol, Rochester, MN 55905 USA
[3] Johns Hopkins Univ, Sch Med, Dept Neurol & Neurosurg, Baltimore, MD USA
[4] Johns Hopkins Univ, Sch Med, Dept Ophthalmol, Baltimore, MD 21205 USA
[5] Johns Hopkins Univ, Sch Med, Dept Otolaryngol, Baltimore, MD 21205 USA
[6] Johns Hopkins Univ, Sch Med, Dept Emergency Med, Baltimore, MD USA