1. Department of Neurosurgery; Gangnam Severance Hospital; Yonsei University College of Medicine; Seoul South Korea
2. Severance Institute for Vascular and Metabolic Research; Yonsei University College of Medicine; Seoul South Korea
3. Department of Neurosurgery; Inha University School of Medicine and Hospital; Incheon South Korea
4. Department of Neurosurgery; Ajou University School of Medicine and Hospital; Suwon South Korea
5. Department of Neurosurgery; Seoul St. Mary's Hospital; , College of Medicine, The Catholic University of Korea; Seoul South Korea