[1] Ewha Womans Univ, Dept Neurol, Coll Med, Seoul, South Korea
[2] Seoul Natl Univ, Bundang Hosp, Dept Neurol, Seongnam, South Korea
[3] Seoul Natl Univ, Bundang Hosp, Dept Crit Care Med, Seongnam, South Korea
[4] Seoul Natl Univ, Coll Med, Bundang Hosp, Dept Neurol, 82 Gumi Ro 173 Beon Gil, Seongnam 13620, Gyeonggi Do, South Korea