1. Department of Neurosurgery, Ajou University School of Medicine, Suwon, Korea (Jae-Ho Kim) (Cho)
2. Department of Anatomy, Yonsei University College of Medicine, Seoul, Korea (Lee)
3. Medical Research Institute, Chungang University College of Medicine, Seoul, Korea (Seung U. Kim)
4. Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, Canada