Central and peripheral processes in headache

Localized and widespread pressure pain hypersensitivity in patients with episodic or chronic migraine: A systematic review and meta-analysis

OBJECTIVE

This meta-analysis compared pressure pain sensitivity in trigeminal, cervical spine and remote pain-free areas between migraine patients and headache-free controls considering diagnosis (episodic versus chronic) and sex.Databases and data treatment: Electronic databases were searched for cross-sectional or prospective case-control studies comparing pressure pain thresholds between migraine and headache-free controls. Data were extracted by two reviewers. The risk of bias and methodological quality was assessed by Newcastle-Ottawa Quality Assessment Scale. Meta-analyses of trigeminal, extra-trigeminal (cervical spine) and remote pain-free areas were compared. Frequency of migraine and sex were taken into account. Mean differences (MD) and random effects were calculated.

RESULTS

Eighteen studies were included. Patients with migraine showed lower pressure pain thresholds than headache-free controls: trigeminal (MD -71.33 kPa, 95%CI -92.14 to -50.53), cervical spine (MD -68.50 kPa, 95%CI -84.67 to -52.33), and remote pain-free (MD -62.49 kPa, 95%CI -99.52 to -25.45) areas. Differences were consistently significant for episodic migraine in all locations, but only significant in the trigeminal area for chronic migraine (MD -67.36 kOPa, 95%CI -101.31 to -33.42). Overall, women had lower pressure pain thresholds than men. The methodological quality of most studies (66.7%) was good. The results showed a high heterogeneity.

CONCLUSION

This meta-analysis found low to high quality evidence showing lower pressure pain thresholds in trigeminal, extra-trigeminal, and remote pain-free areas in migraine sufferers when compared with headache-free controls. Hypersensitivity to pressure pain locally and widespread was consistently observed in episodic migraine, but locally in chronic migraine as compared to headache-free controls. Women with migraine were more sensitive than men.Registration number: https://doi.org/10.17605/OSF.IO/YJTAK.

A critical review of the neurovascular nature of migraine and the main mechanisms of action of prophylactic antimigraine medications

INTRODUCTION

Migraine involves neurovascular, functional, and anatomical alterations. Migraineurs experience an intense unilateral and pulsatile headache frequently accompanied with vomiting, nausea, photophobia, etc. Although there is no ideal preventive medication, frequency in migraine days may be partially decreased by some prophylactics, including antihypertensives, antidepressants, antiepileptics, and CGRPergic inhibitors. However, the mechanisms of action involved in antimigraine prophylaxis remain elusive.

AREAS COVERED

This review recaps some of the main neurovascular phenomena related to migraine and currently available preventive medications. Moreover, it discusses the major mechanisms of action of the recommended prophylactic medications.

EXPERT OPINION

In the last three years, migraine prophylaxis has evolved from nonspecific to specific antimigraine treatments. Overall, nonspecific treatments  mainly involve neural actions, whereas specific pharmacotherapy (represented by CGRP receptor antagonists and CGRPergic monoclonal antibodies) is predominantly mediated by neurovascular mechanisms that may include, among others: (i) reduction in the cortical spreading depression (CSD)-associated events; (ii) inhibition of pain sensitization; (iii) blockade of neurogenic inflammation; and/or (iv) increase in cranial vascular tone. Accordingly, the novel antimigraine prophylaxis promises to be more effective, devoid of significant adverse effects (unlike nonspecific treatments), and more beneficial for the quality of life of migraineurs.