1. Department of Neurology; Samsung Medical Center; Irwon Dong, Kangnam-gu, Seoul 06351 Korea
2. Department of Undeclared Majors; Kyungil University; Hayang-eup, Gyeongsan-si, Gyeongbuk 38428 Korea
3. Department of Anatomy; Korea University College of Medicine; Sungbuk gu, Seoul 02841 Korea
4. Department of Radiology; Korea University College of Medicine; Sungbuk gu, Seoul 02841 Korea