Cluster headache: report of seven cases in three families.

We report here 7 patients with episodic cluster headache belonging to three families. During follow-up, we investigated the occurrence of migraine and other disorders in the patients and their relatives. In two of the three families we recorded the occurrence of migraine and in one of these the presence of chronic daily headache, tension headache, essential tremor and cyclic depression. In the third family we detected the occurrence of systemic arterial hypertension in the father and childhood hyperkinesia in the son. We discuss the possible relations between these diseases, especially between migraine and cluster headache, and suggest a better investigation of cluster headache co-morbidity since such a study may help to further understanding of the physiopathology of the disorder.