[1] Univ Michigan, Dept Neurosurg, 5018 BSRB,109 Zina Pitcher Pl, Ann Arbor, MI 48109 USA
[2] Gifu Univ, Grad Sch Med, Dept Neurosurg, Gifu, Japan
[3] Univ Michigan, Dept Neurosurg, 5018 BSRB,109 Zina Pitcher Pl, Ann Arbor, MI 48109 USA
[4] Gifu Univ, Dept Neurosurg, Grad Sch Med, Gifu, Japan