Cluster headache: myths and the evidence.

Although cluster headache (CH) has been the focus of a great deal of research, it also has been the focus of a great deal of speculations that have been repeated commonly as fact. The authors conducted a thorough review of the literature and an informal poll of several noted headache experts to investigate the truth behind common myths and hypotheses regarding CH. They then present an overview of some of these more common hypotheses, observations, and myths, and offer a brief review of the existing evidence supporting or negating the theories. These include gender, genetics, suicidality, homicidality, physical appearance, personality, and psychologic features of the patient with CH.