Episodic paroxysmal hemicrania: 3 new cases and a review of the literature.

Episodic paroxysmal hemicrania (EPH) is a rare, benign disorder characterized by discrete bouts of hemicranial headaches separated by periods of pain-free remissions. EPH is frequently mistaken for episodic cluster headache because they have similar temporal profiles and clinical features. EPH is differentiated from cluster headaches by an increased frequency and a shorter duration of individual attacks. Establishing the diagnosis of EPH is important because of its unique response to treatment with indomethacin and not standard anti-cluster headache medications.