[1] Ewha Womans Univ, Sch Med, Dept Neurol, Seoul 158710, South Korea
[2] Ewha Med Res Inst, Seoul, South Korea
[3] Ewha Womans Univ, Sch Med, Dept Prevent Med, Seoul 158710, South Korea
[4] Seoul Natl Univ Hosp, Dept Neurol, Seoul 110744, South Korea
[5] Univ Ulsan, Coll Med, Asan Med Ctr, Dept Neurol, Seoul, South Korea
[6] Catholic Univ Korea, Seoul St Marys Hosp, Dept Neurol, Seoul, South Korea
[7] Hallym Univ, Coll Med, Dept Neurol, Seoul, South Korea
[8] Gil Med Ctr, Gachon Med Sch, Dept Neurol, Inchon, South Korea
[9] Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Dept Neurol, Seoul, South Korea