[1] Hallym Univ, Coll Med, Dept Neurol, Sacred Heart Hosp, Anyang, South Korea
[2] Seoul Natl Univ Hosp, Dept Neurol, Seoul, South Korea
[3] Seoul Natl Univ Hosp, Movement Disorders Ctr, Parkinson Study Grp, Seoul, South Korea
[4] Ewha Womans Univ, Dept Neurol, Mokdong Hosp, Seoul, South Korea
[5] Eulji Gen Hosp, Dept Neurol, Seoul, South Korea
[6] Univ Ulsan, Ulsan Univ Hosp, Dept Neurol, Coll Med, Ulsan, South Korea
[7] Seoul Natl Univ, Coll Med, Dept Neurol, Bundang Hosp, Sungnam, South Korea