Relationship between cyclic vomiting syndrome and migraine.

The strength of the association between cyclic vomiting syndrome (CVS) and migraine was explored by studying the prevalence of migraine in patients with CVS and their relatives versus geographic normal controls. A questionnaire was sent to patients with CVS or their parents and to individuals of the same gender and age living within 1 mile of the home of patients with CVS. Patients with CVS, their mothers, and their grandmothers had a prevalence of migraine almost twice as frequent as that in controls.