Risks for cochlear disorders, primarily tinnitus, may be significantly higher in patients with a history of migraines, according to results from a population-based study recently published in JAMA Otolaryngology—Head & Neck Surgery.
“It is still unclear whether migraines might increase the risk of other cochlear disorders, including tinnitus and/or sensorineural hearing impairment, even though migraines do not occur concurrently with cochlear disorders. Therefore, the aim of this study was to examine the risk of cochlear disorders for patients with a history of migraines,” wrote these researchers led by Juen-Haur Hwang, MD, PhD, Department of Otolaryngology, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Dalin, Chiayi, Taiwan.
Using data from the 2005 Taiwan Longitudinal Health Insurance Database, they identified 1,056 patients with migraines (mean age: 36.7 years; 672 women) diagnosed between January 1, 1996, and December 31, 2012, and 4,224 controls.
They compared the incidence of cochlear disorders—including tinnitus, sensorineural hearing impairment, and/or sudden deafness—between the two groups and found a significantly higher cumulative incidence of cochlear disorders in patients with migraines compared with controls (12.2% vs 5.5%, respectively), with a crude hazard ratio (HR) of 2.83 for cochlear disorders (95% CI: 2.01-3.99) and an adjusted HR of 2.71 (95% CI: 1.86-3.93).
In the migraineurs, the incidence of cochlear disorders was 81.4 (95% CI: 81.1-81.8) per 1 million person-years, compared with 29.4 per 1 million person-years (95% CI: 29.2-29.7) in the controls.
Upon subgroup analysis, the researchers also found that migraineurs had an adjusted HR of 3.30 (95% CI: 2.17-5.00) for tinnitus, 1.03 (95% CI: 0.17-6.41) for sensorineural hearing impairment, and 1.22 (95% CI: 0.53-2.83) for sudden deafness.
The mechanisms behind this association between cochlear disorders and migraines is as yet unknown. Dr. Hwang and fellow researchers postulate that “Migraine and cochlear disorders might share common pathophysiologic characteristics. Sleep disorders, trigeminovascular theory, neuroinflammation, and/or cortical hypersensitivity have been associated with migraine.”
They continued: “It could be suggested that the findings do not reflect the cochlea at all and may reflect a central process causing tinnitus. This possibility would need to be investigated further in studies using audiometry; however, it clearly outlines a link between migraine and tinnitus that will be influential.”
In an accompanying editorial, Harrison W. Lin, MD, and Hamid R. Djalilian, MD, Division of Neurotology and Skull Base Surgery, Department of Otolaryngology—Head & Neck Surgery, University of California, Irvine, also consider several vascular and circulatory possibilities:
“Although there are many proposed theories on the pathophysiologic characteristics of migraine, vasospasm of the branches of the posterior cerebral circulation, resulting in compromised blood flow to the inner ear and to the brain, has been proposed as a possible mechanism for migraine-related and episodic hearing and balance symptoms. Cortical spreading depression and altered central processing in the auditory and vestibular cortices could subsequently generate imbalance, nausea, and motion intolerance, among other migraine symptoms.”
They stressed importance of the results obtained by Dr. Hwang and colleagues, but added that larger studies are needed.
“The work by Hwang et al provides valuable and convincing population-based evidence that migraine activity can contribute to the generation of auditory symptoms, including sudden and fluctuating sensorineural hearing loss and tinnitus,” they wrote.
“Data from controlled studies investigating the efficacy of prophylactic antimigraine therapy on conditions such as benign aural fullness, episodic dizziness, and cochlear migraine, among others, would likely further our understanding of the underrecognized role of migraine in hearing and balance disorders,” they concluded.