An 84-year-old man with cognitive dysfunction was taken to the emergency room because of a change in consciousness. He came in with a Glasgow Coma Scale (GCS) score of E4V4M5. According to his family, this was not his usual state. It was difficult to hear the medical history from him, and there were few specific complaints. Upon physical examination, there were no abnormalities on the body surface and no complaints of pain. Head CT was performed to investigate the cause (Fig. 1 A and B).
