Saitama International Headache Center, Saitama Neuropsychiatric Institute, 6-11-1 Honmachi-Higashi, Chuo-ku, Saitama, 338-8577, Japan

Fumihiko Sakai

Department of Neurology, Dokkyo Medical University, 880 Kitakobayashi, Mibu, Shimotsuga, Tochigi, 321-0293, Japan

Koichi Hirata

Department of Internal Medicine, Headache Care Unit, Fujitsu Clinic, 4-1-1 Kamikodanaka, Nakahara-ku, Kawasaki, Kanagawa, 211-8588, Japan

Hisaka Igarashi

Headache Center, Department of Neurology, Tominaga Hospital, 1-4-48 Minatomachi, Naniwa-ku, Osaka-shi, Osaka, 556-0017, Japan

Takao Takeshima

Department of Health Informatics, Graduate School of Medicine and School of Public Health, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan

Takeo Nakayama

Medical Affairs, Otsuka Pharmaceutical Co., Ltd, 3-2-27 Otedori, Chuo-ku, Osaka, 540-0021, Japan

Hiromi Sano

Medical Affairs, Otsuka Pharmaceutical Co., Ltd., Shinagawa Grand Central Tower, 2-16-4, Konan, Minato-ku, Tokyo, 108-8242, Japan

Hiroyuki Kondo & Yoshiyuki Shibasaki

Medical Affairs, Otsuka Pharmaceutical Co., Ltd., 463-10 Kagasuno, Kawauchi-cho, Tokushima, 771-0192, Japan

Nobuyuki Koga