The new numbers behind vestibular migraine

Vestibular migraine (VM) is more common than previously reported, according to a new study recently published in Otology & Neurotology.

“The precise prevalence and demographic characteristics of those with specific vestibular disorders, including [VM], are not well known at the population level,” wrote the authors, led by Eric J. Formeister, MD, Department of Otolaryngology–Head and Neck Surgery, University of California–San Francisco School of Medicine, San Francisco, CA.

Most previous epidemiologic estimates of VM have been based on convenience samples of individuals presenting with symptoms of dizziness or vertigo to neurology and otology clinics and, thus, are not generalizable to the entire population. According to these studies, VM is the second most common etiology of dizziness, following benign paroxysmal positional vertigo, and accounts for 7% to 16% of complaints at dizziness clinics.

In the general population, researchers of a more robust study of German adults determined the 1-year prevalence of VM to be 0.89% and the lifetime prevalence to be 0.98%. 

“The purpose of the present study was to use a case definition for [VM] to then estimate the 1-year prevalence of VM in US adults, and to describe associated demographic and clinical features,” wrote the authors.

The team hypothesized that, based on the high prevalence of both migraine and dizziness, the prevalence of VM would be higher than previously estimated and the risk factors for migraine and VM would be the same, including female sex, younger age, and comorbid psychiatric conditions.

They mined the 2008 National Health Interview Survey, which is an annual cross-sectional interview of US adults, and collected data from 21,781 individuals (51.7% of whom were women; mean age, 46 years) who took an online balance and dizziness survey comprised of 210 items. VM was defined according to consensus criteria published by the Bárány Society and the International Headache Society in 2012.

Respondents characterized as having VM needed to answer the following two questions affirmatively: 1) ‘‘During the past 12 months, have you had a problem with dizziness or balance?’’ and 2) ‘‘Do migraine headaches happen around the same time as your dizziness?”

The investigators also assessed sociodemographic and clinical characteristics to develop a demographic overview of individuals with VM, and to determine whether recognized risk factors for dizziness, migraine, or both were independent risk factors for VM.

The team utilized univariate and multivariate regression to compute odds ratios relating VM and studied demographic and clinical traits.

The investigators discovered that the 1-year prevalence of a dizziness or balance problems was 11.9%. Of these individuals, 23.4% met the criteria for VM, representing an overall prevalence of 2.7%. Most individuals with VM were women (75.8%), and the average age of those with VM was 40.9 years.

Upon multivariate analysis, age < 40 years, female sex, depression, anxiety, and previous head trauma were correlated with increased risk of VM. Smoking, stroke, hypertension, heart disease, diabetes, and hearing loss were not significantly associated with VM. Interestingly, a history of coronary heart disease decreased the risk of VM, possible due to treatment with beta-blockers, which are known to help in the treatment of the vestibular symptoms of VM.

Notably, only 10% of individuals meeting criteria for VM were told by a clinician that their dizziness was caused by migraine. This finding suggests that missed or misdiagnosis of VM is a problem.

The researchers estimated that 23% of individuals with a 1-year prevalence of vestibular symptoms have VM. This estimate is approximately twice the previously estimated prevalence of VM in those pursuing tertiary treatment for vestibular symptoms. On the basis of this finding, only about one-half of individuals with VM are seeking specialty care, which is more likely to yield appropriate diagnosis and treatment.

“[VM] is one of the most prevalent causes of dizziness in the United States, is underdiagnosed, and causes significant impairment of quality of life,” concluded the authors.