A 49-year-old male had been complaining of general fatigue since July 31, 2007. On August 3, he developed a headache in the forehead bilaterally, and he had a slight fever on the next day. At 3:00 a.m. on August 3, a stabbing pain lasting less than 3 seconds suddenly occurred on the right side of the forehead, cheek, and jaw. He felt pain while he was awake. The pain attacks occurred at least once every two or three minutes, and at most once every 10 seconds; attacks occurred with a frequency from 100 to 200 times per day. During the attacks, he showed dacryorrhea, swelling of the eyelids of the right eye, and rhinorrhea. The patient was not able to keep still because of his severe, stabbing headache. During the daytime of August 6, the pain moved to the right occipital and right upper auricular regions. The symptoms persisted, and he was admitted on August 7. His past history and family history were not contributory. The patient reported a stabbing headache in the right side of the forehead, cheek, and jaw, as well as in the upper auricular and occipital regions. On physical examination, Yasuo Ito Toshimasa Yamamoto Mikiko Ninomiya Yoshikazu Mizoi Kaori Itokawa Naotoshi Tamura Nobuo Araki Kunio Shimazu