1. Department of Neurosurgery, Jeju National University College of Medicine, Jeju, Korea.
2. Department of Neurosurgery, Hallym University College of Medicine, Chuncheon, Korea.
3. Department of Neurology, Konkuk University College of Medicine, Seoul, Korea.
4. Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.
5. Department of Neurosurgery, Bundang Jesaeng Hospital, Bundang, Korea.
6. Department of Neurosurgery, Catholic University College of Medicine, Incheon, Korea.