[1] Univ Ulsan, Asan Med Ctr, Dept Neurol, 388-1 Pungnap Dong, Seoul 138736, South Korea
[2] Gachon Univ, Gil Med Ctr, Dept Neurol, Incheon, South Korea
[3] Hanyang Univ, Coll Med, Dept Neurol, Seoul, South Korea
[4] Univ Ulsan, Gangneung Asan Hosp, Dept Neurol, Kangnung, Gangwon Do, South Korea