[1] Inje Univ, Coll Med, Sanggye Paik Hosp, Dept Neurol, Seoul, South Korea
[2] Yonsei Univ, Wonju Coll Med, Seoul 135720, South Korea
[3] Natl Med Ctr, Seoul, South Korea
[4] Yonsei Univ, Coll Med, Seoul 135720, South Korea
[5] Ilsan Hosp, Natl Hlth Insurance Corp, Koyang, South Korea
[6] CHA Univ, Coll Med, Pochon, South Korea
[7] Wonkwang Univ, Coll Med, Sanbon Hosp, Gunpo, South Korea
[8] Ajou Univ, Coll Med, Suwon 441749, South Korea