Review of Japanese Herbal Medicine Treatment (Kampo) for Primary Headache by Analyzing Case Studies

This study aimed to review Japanese case reports to assess the therapeutic patterns, efficacy, and underlying rationale behind Kampo herbal medicine in treating primary headaches. The review was conducted on CiNii, J-STAGE, and PubMed databases using keywords such as “headache,” “migraine,” “tension-type headache,” and “Kampo.” Sixteen studies, encompassing 350 cases, including migraine, tension-type headache (TTH), and cluster headache, were analyzed. The most frequently prescribed formula was Kakkonto (葛根湯), primarily for TTH, followed by Kamishoyosan and Yokukansan. Kampo prescriptions were individualized based on pattern diagnosis, incorporating pulse, tongue, and abdominal findings rather than conventional headache classifications. These findings suggest that Kampo medicine offers a safe, personalized approach to headache management. Moreover, pattern differentiation plays a more central role in prescription decisions than headache subtype.