[1] Univ Ulsan, Ulsan Univ Hosp, Dept Neurol, Coll Med, Ulsan, South Korea
[2] Seonam Univ, Myongji Hosp, Dept Neurol, Coll Med, Goyang, South Korea
[3] Hallym Univ, Coll Med, Sacred Heart Hosp, Dept Neurol, Anyang, South Korea
[4] Ewha Womans Univ, Coll Med, Mokdong Hosp, Dept Neurol, Seoul, South Korea
[5] Eulji Univ, Coll Med, Eulji Gen Hosp, Dept Neurol, Seoul, South Korea
[6] Seoul Natl Univ, Coll Med, Seoul Natl Univ Hosp, Dept Neurol, 101 Daehak Ro, Seoul 110744, South Korea
[7] Seoul Natl Univ Hosp, Parkinsons Dis Study Grp, Seoul, South Korea
[8] Seoul Natl Univ Hosp, Neurosci Res Inst, Seoul, South Korea