Migraine features, associated symptoms and triggers: A principal component analysis in the Women's Health Study

Aims: Migraine has a wide clinical spectrum. Our aim was to group information on migraine characteristics into meaningful components and to identify key components of the migraine phenotype. Methods: We performed two principal component analyses, one among participants in the Women's Health Study enrollment cohort and one in a sub-cohort with additional migraine-specific information. Results: Among the 9427 women with migraine attack-related information at enrollment, the three most important components pertained to central nervous system (CNS) sensitization, attack frequency/pain location and aura/visual phenomena. In the subgroup of 1675 women with more detailed information, food triggers and unspecific symptoms constituted two principal components that explain more of the variance of the migraine phenotype than the three attack-related components. Conclusions: Our results indicate that information on migraine-associated features, symptoms and triggers is highly correlated, allowing the extraction of principal components. Migraine attack-related symptoms are best summarized by symptoms related to CNS sensitization, attack frequency/pain location and aura/visual phenomena. Taking a more general view, unspecific symptoms and food triggers appear to carry stronger importance in characterizing the migraine phenotype. These components are useful for future research on the pathophysiology and genetics of migraine and may have implications for diagnosing and treating patients.