From transformation to chronification of migraine: pathophysiological and clinical aspects

DOI: https://doi.org/10.1186/s10194- 020- 01111- 8

Abstract-Summary The process that describes the development from episodic migraine into chronic migraine is commonly referred to as migraine transformation or chronification.

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2 Mechanisms

Ample studies have attempted to identify factors associated with migraine trans-

formation from different perspectives.

Background To establish the clinical risk factors for chronification and the structural or func- tional neurological changes that occur in patients who evolve to CM studies should include large migraine cohort studies with long-term follow-up.

The Chronic Migraine Epidemiology and Outcomes (CaMEO) study showed that CM patients more frequently reported sleep apnea or were more likely to be at “high risk” for sleep apnea than EM patients [206].

The first comprehensive study on genetic association in CM and high-frequency migraine, tested 144 SNPs from 48 genes in 1019 patients with CM or high- frequency migraine, without finding significant associations [207].

The hypothalamus shows stronger activation in the CM patient than in EM patients in response to painful trigeminal stimulation but also during a migraine attack [208].

A study that have compared EM and CM patients using resting state technique, points to stronger connectivity in the pain matrix of CM patients that might play a role in migraine chronification [209].

Conclusions CM patients show differences compared to EM patients and controls.

EM patients with clinical factors associated to chronification may be on a higher risk for transformation, so it is important to screen for clinical risk factors as well as educate and treat modifiable factors in order to prevent transformation.

Although studies using different approaches have demonstrated functional and structural differences between CM and EM patients, key structures and networks involved in the chronification phenomena, and the pathophysiology of migraine transformation are not fully understood.

Increased levels of glutamate in the CSF, central sensitization, altered habitua- tion to sensory stimuli, impaired cortical inhibition and furthermore when investi- gating magnetic visually evoked responses, and even predicting the state of chronification based on structural imaging, are all compatible with a hypothesis of central and peripheral altered excitability being pivotal changes happening in CM.

Acknowledgement A machine generated summary based on the work of Torres-Ferrús, M.; Ursitti, F.; Alpuente-Ruiz, A.; Brunello, F.; Chiappino, D.; de Vries, T.; Di Marco, S.; Ferlisi, S.; Guerritore, L.; Gonzalez-Garcia, N.; Gonzalez-Martinez, A.; Khutorov, D.; Kritsilis, M.; Kyrou, A.; Makeeva, T.; Minguez-Olaondo, A.; Pilati, L.; Serrien, A.; Tsurkalenko, O.; Van den Abbeele, D.; van Hoogstraten, W. S.; Lampl, C.; 2020 in The Journal of Headache and Pain

2.2 Biology

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Biological insights from the premonitory symptoms of migraine