Chronic migraine: A process of dysmodulation and sensitization.

Chronic migraine is a common chronic daily headache featured by frequent headache attacks with at least 15 headache days per month, which brings great disease burden to both the sufferers and the society. Transformed from episodic migraine, the pathophysiology of chronic migraine is not fully understood, even though several risk factors have been associated with migraine progression. Recent studies have identified both structural and functional alterations in some brain regions of chronic migraine patients indicating that maladaptation of the top-down pain modulation and subsequent sensitization of trigeminal system may be important in the pathogenesis of chronic migraine. Moreover, biochemical analysis has confirmed several molecules related to chronic migraine, which may serve as biomarkers and potential therapeutic targets. Chronic migraine is undertreated because of its poor treatment response and limited therapy options. In this article, we reviewed the latest data to outline the clinical feature, pathophysiological mechanism, and management of chronic migraine, in the expectation to provide direction for future research and finally to take good care of chronic migraine patients.