1. Department of Neurosurgery, Anjo Kosei Hospital, Anjo, Aichi, Japan
2. Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
3. Department of Neurosurgery, Chubu Rosai Hospital, Nagoya, Aichi, Japan
4. Department of Neurosurgery & Endovascular Neurosurgery, Osaka Medical College, Takatsuki, Osaka, Japan