[1] Sungkyunkwan Univ, Samsung Med Ctr, Dept Neurosurg, Sch Med, Seoul, South Korea
[2] Inje Univ, Dept Med Educ, Coll Med, Busan, South Korea
[3] Inje Univ, Inst Med Humanities, Coll Med, Busan, South Korea
[4] Inje Univ, Busan Paik Hosp, Dept Anesthesiol & Pain Med, Coll Med, Busan, South Korea
[5] Inje Univ, Busan Paik Hosp, Dept Pediat, Coll Med, 75 Bokji Ro, Busan 47392, South Korea