1. Department of Neurosurgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul 06974, Korea.
2. Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Korea.
3. Department of Neurosurgery, Dongguk University Ilsan Hospital, Dongguk University College of Medicine, Goyang 10326, Korea.
4. Department of Neurosurgery, Kwangju Christian Hospital, Gwangju 61661, Korea.
5. Department of Neurology, International St. Mary's Hospital, Catholic Kwandong University of Korea College of Medicine, Incheon 22711, Korea.
6. Department of Neurosurgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Korea.