Migraine is associated with recurrent attacks that can vary in frequency, duration and resulting disability. Correctly diagnosing migraine can take time and, on average, patients with migraine spend longer periods awaiting correct diagnosis, compared to headache sufferers (Naujoks et al., 2016).
There is no test to definitively diagnose migraine and no biomarkers are currently available to assist in the process (International Headache Society, 2013). In some cases, computed tomography (CT) or magnetic resonance image (MRI) scans are used during the diagnostic journey; however, this is only to rule out other causes of headache.
There are three key diagnostic components for migraine:
Table 4: Differentiating migraine from other primary headache diseases (Russell, 2007; Burch et al., 2015; International Headache Society, 2018)
International guidelines are available for migraine diagnosis (Manack et al., 2009; International Headache Society, 2018). In total, the International Classification of Headache Disorders 3 (ICHD-3) lists 14 distinct diagnoses for headache disorders, however severe headache patients may receive multiple sub-diagnoses that fall into one or more of the main diagnostic categories.
Migraine can be further divided into two major subtypes: with- and without aura. Classification of each is based on the ICHD criteria (Katsarava et al., 2012; International Headache Society, 2018).
The 2004 ICHD-2 guidelines provided a definition of, and distinction between, episodic migraine versus chronic migraine, which was further refined within the 2018 ICHD-3 guidelines. Classification of migraines as episodic or chronic depends on attack frequency (Katsarava et al., 2012; International Headache Society, 2018):
It is important for physicians to bear in mind that migraine may worsen over time, with increasing headache frequency (Bigal & Lipton, 2008) and may evolve, transitioning from episodic to chronic – a process termed ‘chronification’ (Manzoni et al., 2013). Conversely, migraine may also transition from chronic to episodic (Bigal & Lipton, 2008).