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Migraine, sudden sensorineural hearing loss and autoimmune ear disease

We have read with attention the article entitled ‘‘Migraine is a risk factor for sudden sensorineural hearing loss: A nationwide population-based study’’ by Chu et al. (1). The authors have reported a welldesigned retrospective study in two cohorts of migraine and non-migrainous patients matching by age, sex and comorbidities such as diabetes, hypertension, dyslipidemia and atrial fibrillation. Although this matching has avoided a selection bias for vascular risk factors, the authors have not considered systemic autoimmune diseases, and they can be associated with sensorineural hearing loss. We have found a higher prevalence of rheumatoid arthritis, systemic lupus erythematous and ankylosing spondylitis in patients with Meniere’s disease (MD) and migraine than in patients with MD and tension-type headache (2). Interestingly, the authors have excluded MD as a cause of sudden onset sensorineural hearing loss (SSNHL), but they have not considered vestibular migraine (VM). The reported incidence rate of MD seems too high when compared to published rates (227 MD patients of a total of 13,532 migraine patients during the 10-year follow-up). It should also be noted that about 50% of patients with MD meet criteria for migraine (3). It is our opinion that several of the excluded MD patients were probably VM sufferers, and some migraine patients with SSNHL may correspond to VM patients. VM is probably the most common cause of recurrent spontaneous vertigo (4). The relation between migraine and MD is well known. An increased prevalence of migraine in MD patients has been reported in several studies; likewise migraine may predispose to develop MD. Vestibular migraine and MD overlap in presentation and may be misdiagnosed. It has been proposed that both conditions share a common pathophysiology and may even be inherited as a symptom cluster. The diagnostic criteria of VM will be included in the appendix of the next review of the International Headache Classification. This will contribute to elucidating the differential diagnosis. Cochlear symptoms are also present in VM. Although phonophobia is the most common auditory symptom, 50% of VM patients refer tinnitus and 34% report hearing loss (5). Hearing loss is usually episodic in VM, but permanent unilateral hearing loss and SSNHL has also been reported in vestibular migraine. We suggest that autoimmune inner ear disease may explain the differences in SSNHL between both groups. Regardless, these comments do not decrease the merit of the study.