RESEARCH PAPER Vestibular vertigo and comorbid cognitive and psychiatric impairment: the 2008 National Health Interview Survey Robin T Bigelow, 1 Yevgeniy R Semenov, 1 Sascha du Lac, 1,2 Howard J Hoffman, 3 Yuri Agrawal 1 1 Department of Otolaryngology–Head & Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA 2 Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA 3 Epidemiology and Statistics Program, Division of Scientific Programs, National Institute on Deafness and Other Communication Disorders (NIDCD), National Institutes of Health (NIH), Bethesda, Maryland, USA Correspondence to Robin T Bigelow, Department of Otolaryngology–Head & Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; rbigelow@jhmi.edu Received 6 January 2015 Revised 19 March 2015 Accepted 19 March 2015 To cite: Bigelow RT, Semenov YR, du Lac S, et al. J Neurol Neurosurg Psychiatry Published Online First: [ please include Day Month Year] doi:10.1136/ jnnp-2015-310319 ABSTRACT Background/aims Patients with vestibular disease have been observed to have concomitant cognitive and psychiatric dysfunction. We evaluated the association between vestibular vertigo, cognitive impairment and psychiatric conditions in a nationally representative sample of US adults. Methods We performed a cross-sectional analysis using the 2008 National Health Interview Survey (NHIS), which included a Balance and Dizziness Supplement, and questions about cognitive function and psychiatric comorbidity. We evaluated the association between vestibular vertigo, cognitive impairment (memory loss, difficulty concentrating, confusion) and psychiatric diagnoses (depression, anxiety and panic disorder). Results We observed an 8.4% 1-year prevalence of vestibular vertigo among US adults. In adjusted analyses, individuals with vestibular vertigo had an eightfold increased odds of ‘serious difficulty concentrating or remembering’ (OR 8.3, 95% CI 4.8 to 14.6) and a fourfold increased odds of activity limitation due to difficulty remembering or confusion (OR 3.9, 95% CI 3.1 to 5.0) relative to the rest of the US adults. Individuals with vestibular vertigo also had a threefold increased odds of depression (OR 3.4, 95% CI 2.9 to 3.9), anxiety (OR 3.2, 95% CI 2.8 to 3.6) and panic disorder (OR 3.4, 95% CI 2.9 to 4.0). Conclusions Our findings indicate that vestibular impairment is associated with increased risk of cognitive and psychiatric comorbidity. The vestibular system is anatomically connected with widespread regions of the cerebral cortex, hippocampus and amygdala. Loss of vestibular inputs may lead to impairment of these cognitive and affective circuits. Further longitudinal research is required to determine if these associations are causal. INTRODUCTION Dizziness is a common symptom that affects 11–30% of the US population. 1–5 A number of impairments can produce the phenotype of dizzi- ness, including presyncope, low vision and vestibu- lar loss. 6 The population-based prevalence, specifically of vestibular vertigo, was previously esti- mated in the adult German population. Vestibular vertigo, defined as rotational vertigo, positional vertigo or recurrent dizziness with nausea and either oscillopsia or imbalance, was found to have a life- time prevalence of 7.4%. 7 Vestibular dysfunction is classically associated with a number of physical adverse outcomes, includ- ing postural instability and falls. A growing body of literature is demonstrating the broad range of cogni- tive impairments associated with vestibular dysfunc- tion, including learning disability, and deficits in memory, executive function and visuospatial ability. 8–16 Published accounts dating back to the first century also link vestibular disease to psychi- atric symptoms, including panic disorder, anxiety and depression. 6 17–23 Moreover, some authors have provocatively hypothesised that vestibular loss may induce a negative affective response, which in turn may lead to cognitive impairment. 24–26 In this study, we analysed data from the 2008 National Health Interview Survey (NHIS) to estimate the prevalence of vestibular vertigo in US adults, and evaluate whether individuals with vestibular vertigo are more likely to have concomitant cognitive comorbidities (specifically memory loss and confu- sion) and psychiatric comorbidities (specifically depression, anxiety, panic disorder and psychological distress) relative to individuals without vestibular vertigo. Moreover, we used structural equation mod- elling to test the hypothesis that psychiatric disease may in part mediate the association between vestibu- lar vertigo and cognitive impairment. METHODS The NHIS is an annual household interview survey conducted by the Census Bureau to track health status among the civilian, non-institutionalised US population. The survey is conducted using stratifica- tion, multistage sampling and a probability cluster sampling technique with over sampling of minorities to improve statistical estimates. With sponsorship from the National Institute on Deafness and Other Communication Disorders, National Institutes of Health, the 2008 NHIS was the first nationally rep- resentative survey to include a broad range of ques- tions on balance and dizziness problems in the US adult population. The respondents were asked if, in the previous 12 months, they experienced any one of a number of dizziness or balance problems. Respondents with one or more balance problems were asked more detailed questions to assess the type and severity of their symptoms. Additionally, respondents were asked detailed questions about general health status, comorbidities and mental health. A total of 21 781 individuals aged 18 or older were interviewed in 2008, of whom 20 950 Bigelow RT, et al. J Neurol Neurosurg Psychiatry 2015;0:1–6. doi:10.1136/jnnp-2015-310319 1 Neuropsychiatry JNNP Online First, published on April 17, 2015 as 10.1136/jnnp-2015-310319 Copyright Article author (or their employer) 2015. Produced by BMJ Publishing Group Ltd under licence. group.bmj.com on April 18, 2015 - Published by http://jnnp.bmj.com/ Downloaded from