1. Department of Neurosurgery, St. Vincent’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
2. Department of Neurosurgery, Yeouido St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
3. Department of Neurosurgery, Soonchunhyang University Bucheon Hospital, College of Medicine, Soonchunhyang University, Bucheon, Republic of Korea