[1] Mayo Clin, Dept Ophthalmol, 200 First St Southwest, Rochester, MN 55905 USA
[2] Mayo Clin, Dept Neurol, Rochester, MN USA
[3] Mahidol Univ, Fac Med Siriraj Hosp, Dept Med, Div Neurol,Siriraj Hosp, Mahidol, Thailand
[4] Univ Illinois, Illinois Eye & Ear Infirm, Dept Ophthalmol & Visual Sci, Chicago, IL USA