1. Department of Neurosurgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
2. Department of Neurosurgery, Ilsan Paik Hospital, College of Medicine, Inje University, Goyang, Republic of Korea
3. Department of Neurosurgery, Inha University College of Medicine and Hospital, Incheon, Republic of Korea
4. Department of Neurosurgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
5. Department of Neurosurgery, Gil Medical Center, Gachon University College of Medicine, Incheon, Republic of Korea
6. Department of Neurosurgery, Ajou University College of Medicine and Hospital, Suwon, Republic of Korea