Menstrual Migraine is Not Pathogenetically Related to Premenstrual Syndrome

Facchinetti and colleagues present epidemiological evidence regarding comorbidity between menstrual migraine and premenstrual syndrome, and suggest that premenstural symptoms should be incorporated in the diagnostic criteria for menstrual migraine (1). The crux of the matter, however, should be the concern regarding the nature or biological significance of the common neuroendocrine link of transient and cyclic failure of endogenous opioid activity in both premenstrual syndrome and menstrual migraine patients. Is this a primary event of pathogenetic importance (which would merit inclusion in the definition) or the concomitant side effect of a carefully orchestrated adaptive mechanism?