[1] Natl Taiwan Univ Hosp, Div Neurosurg, Dept Surg, Taipei, Taiwan
[2] Natl Taiwan Univ Hosp, Spine Tumor Ctr, Taipei, Taiwan
[3] Hallym Univ, Coll Med, Dept Neurosurg, Chunchon, South Korea
[4] Yee Zen Gen Hosp, Dept Neurosurg, Taoyuan, Taiwan
[5] Univ Manchester, Fac Biol Med & Hlth, Sch Hlth Sci, Manchester, England
[6] Yee Zen General Hosp, Dept Neurosurg, 30, Yangshin North Rd Lane 321, Taoyuan, Taiwan