Scientific basis of migraine: speculation on the relationship to cyclic vomiting.

The pathogenesis of migraine is reviewed. Migraine is a brain disorder that is activated by various triggers working on a susceptibility to attacks, in part genetically determined. The frequency of attacks is determined by triggers working on a threshold that determines excitability of brain. The mechanisms of the attack may involve both cortical and brain-stem structures and their dysfunction. It remains to be determined if cortical or brain-stem centers "generate the attack." Because migraine involves severe nausea and vomiting, this review contains speculations on similarities in the mechanisms of migraine and cyclic vomiting.