[1] Univ Penn, Hosp Univ Penn, Sch Med, Dept Neurol,Div Neuroophthalmol, Philadelphia, PA 19104 USA
[2] Childrens Hosp Philadelphia, Neuroophthalmol Serv, Philadelphia, PA 19104 USA
[3] Childrens Hosp Philadelphia, Dept Radiol, Philadelphia, PA 19104 USA
[4] Childrens Hosp Philadelphia, Div Neurol, Philadelphia, PA 19104 USA