Cluster headache responsive to indomethacin: Case reports and a critical review of the literature

Abstract

Response to indomethacin is an essential feature for the diagnosis of both paroxysmal hemicrania (PH) and hemicrania continua (HC). Cluster headache (CH) is widely considered to be a disease unresponsive to indomethacin. We report four patients with CH who responded to indomethacin. Two patients, who were refractory to the usual therapy for CH, fulfilled the criteria for chronic CH. Conversely, two patients had a history of episodic CH and showed response to both indomethacin and the usual therapy for CH. We also reviewed the literature for the presence of indomethacin response in patients with CH. We noted a large number of cases labeled as CH by the authors which showed a response to indomethacin. Many cases of definite or possible CH were wrongly labeled as PH because of patients' responding to indomethacin. The response to indomethacin in patients with CH may not be as immediate as in other indomethacin-responsive headaches, and many patients may need larger doses.