[1] Seoul Natl Univ Hosp, Stroke & Neurol Stem Cell Lab, Clin Res Inst, Dept Neurol, Seoul 110744, South Korea
[2] Korea Ctr Dis Control & Prevent, Dept Dis Invest & Surveillance, Seoul, South Korea
[3] Seoul Natl Univ Hosp, Ctr Alcohol & Drug Addict Res, Seoul 110744, South Korea
[4] Ajou Univ, Brain Dis Res Ctr, Suwon 441749, South Korea
[5] Univ British Columbia, UBC Hosp, Dept Med, Div Neurol, Vancouver, BC V5Z 1M9, Canada