1. Department of Anesthesiology and Pain Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Republic of Korea;
2. Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Republic of Korea;
3. Department of Neurosurgery, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Republic of Korea;
4. Department of Otolaryngology, Kyung Hee University, Seoul, Republic of Korea;
5. Department of Otolaryngology, ENT, Kyung Hee University, Seoul, Republic of Korea