[1] Hokkaido Univ, Fac Sci, Dept Math, Kita Ku, Kita 10 Nishi 8, Sapporo, Hokkaido 0600810, Japan
[2] Chubu Univ, Acad Emerging Sci, 1200 Matsumoto Cho, Kasugai, Aichi 4878501, Japan
[3] Kyoto Univ, Dept Neurol, Grad Sch Med, Sakyo Ku, Kyoto 6068507, Japan
[4] Ehime Univ, Dept Neurosurg, Grad Sch Med, 454 Shitsukawa, Toon, Ehime 7910295, Japan
[5] Kobe Univ, Div Neurol, Grad Sch Med, Chuo Ku, 7-5-1 Kusunoki Cho, Kobe, Hyogo 6500017, Japan
[6] Kyoto Univ, Dept Epilepsy Movement Disorder & Physiol, Sakyo Ku, Kyoto 6068507, Japan