Headache disorders are among the leading causes of years lived with disability, in both men and women.1 Chronic migraines, in particular, are typically estimated to have a global prevalence of 1.4–2.2%.2 Despite this extended disease burden and high prevalence, diagnosing migraines and other headaches disorders remains challenging. To this effect, the 3rd edition of the International Classification of Headache Disorders (ICHD-3), detailing headache and migraine diagnostic criteria, was recently published.1
Prof. Morris Levin (UCSF Medical Center, USA) contributed to the 2019 AAN Annual Meeting session Hot Topics in Headaches and Related Disorders II: Migraine Pathophysiology, Brain Imaging and Therapeutic Advances with a presentation on diagnosis of chronic migraine.1 According to ICHD-3, “each distinct type, subtype or subform of headache that the patient has must be separately diagnosed and coded”.3 This point exactly addresses one of the challenges of diagnosing migraines described by Prof. Levin – patients may suffer from different types of headaches at different times. Due to the frequent and continuous nature of the headaches suffered by chronic migraine patients, it is impossible to distinguish individual headache episodes.
Chronic migraines are, therefore, defined as headaches occurring for 15 days or more per month for at least three months in patients who fulfil eight or more criteria for migraines with or without aura.3 Prof. Levin added that medication overuse leading to frequent migraine attacks should be classified as both chronic migraine and medication-overuse headache (MOH). Only if causality is proven – for example, headache improvement upon treatment reduction or discontinuation – can MOH be differentiated from chronic migraine. Prof. Levin highlighted the importance of determining how the headaches initially developed and recognising patterns of primary and secondary headaches. He also reviewed key features such as the nature of the pain, associated symptoms, response to treatment and medical history. In conclusion, Prof. Levin emphasised that only when the diagnosis is comprehensive and systematic will the appropriate treatment approach for each individual patient be achieved.
- GBD 2017 Disease and Injury Incidence and Prevalence Collaborators. Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017. Lancet. 2018;392:1789–858.
- JL Natoli et al. Global prevalence of chronic migraine: a systematic review. Cephalalgia. 2010;30:599–609.
- Headache Classification Committee of the International Headache Society (IHS). The International Classification of Headache Disorders, 3rd edition. Cephalalgia. 2018;38:1–211.
- M Levin. Hot Topics in Headaches and Related Disorders II: Migraine Pathophysiology, Brain Imaging and Therapeutic Advances. Presented at AAN Annual Meeting, 4–10 May, 2019.