Diagnosis and Management of Vestibular Migraine

Basilar-type Migraine

The term basilar migraine should be restricted to patients who fulfill the ICHD diagnostic criteria [35] given it is a clinically distinct entity from VM. Less than 10% of VM patients further fulfill the ICHD criteria for basilar migraine [2,18]. More than 60% of basilar-type migraine patients have vertigo and there are many overlapping clinical manifestations with VM. This diagnosis requires at least 2 symptoms from aura in the posterior circulation territory, whereas most patients with VM have vestibular symptoms only [35]. Moreover, in basilar migraine the duration of vertigo should correspond to the length of an aura, that is, between 5 and 60 minutes [35]. Further studies are required to further elucidate and delineate these 2 conditions.

Other Important Diagnostic Considerations

Meniere’s Disease

An important differential diagnosis of VM is the early presentation of Meniere’s disease (MD). Although fluctuating hearing loss, aural fullness and episodic vertigo are important symptoms in the recent updated diagnostic criteria for definite MD [36,37], these symptoms have been reported in patients with migraine [38]. Moreover, minor abnormalities in cVEMPs and arguably in caloric testing can be found in VM patients, as previously mentioned. Predominantly, the distinction can be made considering that a more sustained, albeit occasionally fluctuating, hearing loss would occur in MD, which can progress to severe hearing loss within a few years. However, the diagnosis can be difficult considering that audiometric and vestibular function abnormalities as well as the typical cochlear symptoms are often absent in the early stages of the MD. Nonetheless, preclinical labelling of patients with episodic vertigo without hearing loss as “vestibular MD” is unhelpful as this population may be overrepresented by actual migraineurs. Studies of patients with so-called benign recurrent vertigo or recurrent vestibulopathy are likely to be heterogeneous entities, with perhaps cases later evolving into VM or MD.

Coexisting migraine and MD is often challenging both in terms of diagnosis and management. Many studies have shown an increased prevalence of migraine in MD patients compared to controls [39,40], an asso-ciation suggested by Prosper Ménière himself in 1861 [41]. A study by Radtke et al found that the lifetime prevalence of migraine with and without aura was over 2 times higher in definite MD patients of both sexes compared to age-matched controls (56% versus 25%) [39]. Interestingly, 45% of the patients with MD always experienced at least 1 migrainous symptom (migrainous headache, photophobia, aura symptoms) with their Meniere attacks [39]. This may be at least partly due to the triggering effect of vestibular symptoms on migraineurs [30]. Migraine may even influence the disease course of MD as indicated by a retrospective case control study which found that definite MD patients who have concomitant ICHD criteria for migraine [35] had a significantly earlier onset of MD symptoms (mean age, 37.2 versus 49.3 years) and a much greater susceptibility to simultaneous bilateral, but not sequential, hearing loss as compared to MD patients without migraine (56% versus 4%) [42]. There were no significant differences in the severity of hearing loss between the 2 groups even when controlling for time to evaluation [42]. A family history of episodic vertigo was seen in 39% of MD patients with migraine, which is significantly higher than the 2% seen in MD patients, suggesting a possible genetic basis for this association [42]. The nature of the association between migraine and MD is not well elucidated, however, some authors propose that migraine leads to isolated microvascular ischaemic damage of the inner ear, presumably through small arterial vasospasm [40,42].