[1] Seoul Natl Univ Hosp, Dept Neurol, Clin Res Inst, Seoul 110744, South Korea
[2] Seoul Natl Univ Hosp, Clin Res Inst, Neurosci Res Ctr, Seoul 110744, South Korea
[3] Ajou Univ, Sch Med, Dept Neurol, Suwon 441749, South Korea
[4] Ajou Univ, Sch Med, Inst Med Sci, Brain Dis Res Ctr, Suwon 441749, South Korea
[5] Seoul Natl Univ Hosp, Dept Neurosurg, Seoul 110744, South Korea
[6] Univ British Columbia, Dept Neurol, Vancouver, BC V5Z 1M9, Canada
[7] Chung Ang Univ, Sch Med, Med Res Inst, Seoul, South Korea