Potential Contribution of Hypertension to Evolution of Chronic Migraine and Related Mechanisms.

AIMS

To investigate the potential contributions of diastolic and systolic blood pressure (BP) and the circadian rhythm of BP to chronic migraine evolution.

METHODS

This cross-sectional study included four groups of patients selected based on migraine frequency (high frequency ≥ 10 days per month and low frequency < 10) and on the presence of hypertension. Among-group and pairwise comparisons were carried out to investigate potential neurophysiologic differences in the cerebral vessel reactivity to a nitroglycerin test, in autonomic balance (tilting test), and BP circadian rhythm.

RESULTS

A more marked decrease in cerebral blood flow velocity was observed in hypertensive high-frequency migraineurs compared to all other groups (P = .037). Moreover, a smaller decrease in vagal tone was recorded in the orthostatic position in hypertensive subjects, whether they were high- (P = .032) or low-frequency migraineurs (P = .014), with a consistently higher vagal to sympathetic tone ratio (P = .033). Finally, in nonhypertensive subjects, a higher but not significant prevalence of systolic nondippers was detected in high-frequency migraineurs (67%) compared to low-frequency subjects (25%; P = .099).

CONCLUSION

These findings suggest that hypertension may contribute to the chronic evolution of headache with mechanisms shared with migraine; ie, vascular tone alteration and autonomic dysregulation.