Mechanisms of migraine as a chronic evolutive condition

DOI: https://doi.org/10.1186/s10194- 019- 1066- 0

Abstract-Summary Understanding the mechanisms of migraine remains challenging as migraine is not a static disorder, and even in its episodic form migraine remains an “evolutive” chronic condition.

Considerable progress has been made in elucidating the pathophysiological mechanisms of migraine, associated genetic factors that may influence susceptibil- ity to the disease, and functional and anatomical changes during the progression of a migraine attack or the transformation of episodic to chronic migraine.

As a disorder, migraine involves recurrent intense head pain and associated

unpleasant symptoms.

Migraine attacks evolve over different phases with specific neural mechanisms

and symptoms being involved during each phase.

Extended: Considerable progress has been made in elucidating the pathophysio- logical mechanisms of migraine, associated genetic factors that may influence sus- ceptibility to the disease and functional and anatomical changes during the progression of a migraine attack, or the transformation of episodic to chronic migraine.

Introduction Beyond functional changes, differences in the structural brain integrity, involving both the white and gray matter, which evolve over time, have been reported by sev- eral studies between migraine patients and controls.

Despite the number of studies on pain pathways involved during the headache phase [174], the molecular changes that actually trigger a migraine attack in the brain remain unknown.

2.2 Biology

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Of interest, an fMRI study of daily brain scans in a migraine patient reported a strong association for both hypothalamic and cortical activity during the premoni- tory phase of an attack [175].

Despite the various evidence of increased blood flow changes in different brain nuclei before or during the onset of the headache phase, what really alters the excit- ability of the ascending trigemino-thalamic pathway in a manner that a migraine headache may develop in susceptible individuals remains to be revealed.

Conclusions These changes may include transformation from episodic to chronic migraine or even a disappearance of some or all migraine symptoms all together.

Genetic and epigenetic susceptibility may be responsible for such changes, although to date, studies failed to shed any light on how such genetic alterations may be responsible for migraine pathophysiology or any evolutive mechanism.

The causality dilemma of whether such changes are responsible for how migraine evolves, or whether migraine mechanisms drive these anatomic changes, remains to be answered.

Even in its episodic form, migraine is an evolutive condition with different

mechanisms involved in the evolutive process of a migraine attack.

The mechanisms that underlie the development of chronic migraine from its epi-

sodic form are not well understood.

The continuous changes in migraine phenotype and pathophysiology during a migraine attack between episodic and chronic migraine and during the patient lifes- pan, make migraine, even in its episodic form, a chronic evolutive disease.

Acknowledgement A machine generated summary based on the work of Andreou, Anna P.; Edvinsson, Lars2019 in The Journal of Headache and Pain.

Hypothalamus loses control in migraine