[1] Seoul Natl Univ, Coll Med, Metropolitan Boramae Hosp, Dept Neurol, Seoul 110799, South Korea
[2] Seoul Natl Univ, Seoul Natl Univ Hosp, Coll Med, Dept Lab Med, Seoul 110799, South Korea
[3] Seoul Natl Univ, Neurosci Res Inst, Coll Med, Dept Neurol, Seoul 110799, South Korea
[4] Seoul Natl Univ, Coll Med, CRI, Program BK21, Seoul 110799, South Korea