[1] Univ Toronto, Univ Hlth Network, Toronto Western Hosp, Dept Surg,Div Neurosurg, Toronto, ON, Canada
[2] Univ Tartu, Sch Med, Dept Neurosurg, Tartu, Estonia
[3] Univ Louisville, Sch Med, Dept Neurosurg, Louisville, KY USA
[4] Henan Univ, Henan Univ Peoples Hosp, Sch Med, Dept Neurosurg, Zhengzhou, Peoples R China
[5] Univ Toronto, Joint Dept Med Imaging, Toronto, ON, Canada
[6] Shonantobu Gen Hosp, Dept Neurol, Kobe, Japan
[7] Shonan Fujisawa Tokushukai Hosp, Dept Neurol, Fujisawa, Japan
[8] Tokyo Womens Med Univ, Dept Neurosurg, Tokyo, Japan
[9] Krembil Res Inst, Toronto, ON, Canada
[10] Univ Toronto, Univ Hlth Network, Toronto Western Hosp, Div Neurosurg, 399 Bathurst St,WW 4-431, Toronto, ON M5T 2S8, Canada