[1] Yonsei Univ, Med Ctr, Dept Neurol, Coll Med, Seoul 120752, South Korea
[2] Yonsei Univ, Coll Med, Brain Res Inst, Seoul 120752, South Korea
[3] Univ Ulsan, Coll Med, Dept Neurol, Parkinson & Alzheimer Ctr,Asan Med Ctr, Seoul, South Korea
[4] Natl Hlth Insurance Corp Hosp, Dept Neurol, Goyang, South Korea
[5] Yonsei Univ, Coll Med, Brain Korea 21 Project Med Sci, Seoul, South Korea