Recent studies suggest an association between vestibular and cognitive function. The goal of the study was to investigate whether vestibular function was impaired in individuals with mild cognitive impairment (MCI) and Alzheimer's disease (AD) compared with cognitively normal individuals.
Outpatient memory clinic and longitudinal observational study unit.
Older individuals ≥55 years with MCI or AD. Age, sex, and education-matched normal controls were drawn from the Baltimore Longitudinal Study of Aging (BLSA).
Saccular and utricular function was assessed with cervical and ocular vestibular-evoked myogenic potentials (c- and oVEMPs) respectively, and horizontal semicircular canal function was assessed with video head impulse testing.
Presence or absence of VEMP responses, VEMP amplitude, and vestibular ocular reflex (VOR) gain were measured.
Forty-seven individuals with cognitive impairment (MCI N = 15 and AD N = 32) underwent testing and were matched with 94 controls. In adjusted analyses, bilaterally absent cVEMPs were associated with an over three-fold odds of AD (OR 3.42, 95% CI 1.33–8.91, p = 0.011). One microvolt increases in both cVEMP and oVEMP amplitudes were associated with decreased odds of AD (OR 0.28, 95% CI 0.09–0.93, p = 0.038 and OR 0.92, 95% CI 0.85–0.99, p = 0.036, respectively). There was no significant difference in VOR gain between the groups.
These findings confirm and extend emerging evidence of an association between vestibular dysfunction and cognitive impairment. Further investigation is needed to determine the causal direction for the link between peripheral vestibular loss and cognitive impairment.
*Department of Otolaryngology–Head and Neck Surgery
†Department of Medicine
‡Department of Psychiatry and Behavioral Sciences
§Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
||Longitudinal Studies Section, Translational Gerontology Branch, National Institute of Aging, National Institutes of Health, Baltimore, Maryland
Address correspondence and reprint requests to Aisha Harun, M.D., 601 N. Caroline St Suite 6210, Department of Otolaryngology–Head and Neck Surgery, Baltimore, MD 21287; E-mail: email@example.com
AH was funded by a NIH T32 Award (5T32DC000027–25) and an AAO-HNSF Core Grant (349386). RB was funded by a T32 Award (NIH/NIDCD 5T32DC000030–1). YA was funded by a NIH K23 Award (5K23DC013056–02). EO was funded by a NIA/NIH K23 Award (1K23AG043504–01), the Roberts Gift Fund, and the Ossoff Family Fund. The Alzheimer's disease Research Council is supported by an NIA award (3P50AG005146–32S1). The Baltimore Longitudinal Study of Aging is supported by an NIA award (1ZIAAG000015–57).
The authors disclose no conflicts of interest.