[1] Hallym Univ, Kangnam Sacred Heart Hosp, Dept Neurol, Coll Med, Seoul, South Korea
[2] Seoul Natl Univ Hosp, Dept Neurosurg, Seoul, South Korea
[3] Gyeongsang Natl Univ, Sch Med, Dept Neurol, Changwon Hosp, Chang Won, South Korea
[4] Ulsan Univ, Dept Neurol, Ulsan Univ Hosp, Coll Med, Ulsan, South Korea
[5] Keimyung Univ, Dept Neurol, Dongsan Med Ctr, Daegu, South Korea
[6] Seoul Natl Univ Hosp, Dept Neurol, 101 Daehak Ro, Seoul 03080, South Korea