1. Department of Neurosurgery, Ashikaga Red Cross Hospital, Ashikaga City, Japan
2. Department of Pathology, Ashikaga Red Cross Hospital, Ashikaga City, Japan
3. Department of Oral Surgery, Ashikaga Red Cross Hospital, Ashikaga City, Japan
4. Department of Otorhinolaryngology, Ashikaga Red Cross Hospital, Ashikaga City, Japan