1. Department of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul 120-752, Republic of Korea
2. Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul 120-752, Republic of Korea
3. Department of Neurosurgery, Yonsei University College of Medicine, Seoul 120-752, Republic of Korea
4. Department of Pediatrics, Severance Children’s Hospital, Yonsei University College of Medicine, Seoul 120-752, Republic of Korea
5. BK21 Plus Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, Republic of Korea