[1] Catholic Univ Korea, Kangnam St Mary Hosp, Coll Med, Dept Neurol, Seoul 137701, South Korea
[2] Dong A Univ, Coll Med, Dept Neurol, Pusan, South Korea
[3] Sungkyunkwan Univ, Sch Med, Samsung Med Ctr, Dept Neurol, Seoul, South Korea
[4] Seoul Natl Univ, Coll Med, Dept Neurol, Seoul 110744, South Korea
[5] Catholic Univ Korea, Coll Med, Dept Biostat, Seoul, South Korea