[1
]
Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College
of Medicine, Severance Hospital, 134 Shinchon-dong Seodaemun-gu, Seoul 120-752, Korea.
[2
]
Department of Neurosurgery, Kangbuk Samsung Hospital, Sungkyunkwan University School
of Medicine, 25-2, Sungkyunkwan-ro, Seoul, Seoul 110-745, Korea.
[3
]
Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College
of Medicine, Severance Hospital, 134 Shinchon-dong Seodaemun-gu, Seoul 120-752, Korea;
Department of Neurosurgery, Brain Korea 21 PLUS Project for Medical Science, College
of Medicine, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, Seoul 120-749,
Korea. Electronic address: ayoon@yuhs.ac.