[1] Seoul Natl Univ Hosp, Coll Med, Dept Neurol, Seoul 110744, South Korea
[2] Seoul Natl Univ Hosp, Coll Med, Dept Movement Disorder Ctr, Seoul 110744, South Korea
[3] Seoul Natl Univ Hosp, Coll Med, Parkinson Dis Study Grp, Seoul 110744, South Korea
[4] Seoul Natl Univ Hosp, Coll Med, Neurosci Res Inst, BK21, Seoul 110744, South Korea
[5] Seoul Natl Univ, Boramae Hosp, Dept Neurol, Seoul 110744, South Korea
[6] Seoul Natl Univ Hosp, Coll Med, Dept Neurosurg, BK21, Seoul 110744, South Korea