Elucidating links between vestibular function, cognition, and sensorimotor behavior

Every year, nearly 25-50% of older adults fall. However, fall prevention efforts are not uniformly effective and factors contributing to fall risk are not completely understood. The vestibular system, part of the inner ear, is a known contributor to fall risk and recent evidence suggests that cognition may interact with vestibular function to influence falls. Patients with Alzheimer’s disease (AD) fall 2-3 times more than cognitively healthy adults and those with vestibular dysfunction exhibit changes in cognition. However, these relationships have not been fully elucidated. As the vestibular system is diverse, identifying which functional pathways (i.e., reflexive, perceptual, visual-vestibular integration) are related to both cognition and imbalance is vital for development of targeted interventions to reduce falls. The specific aims examine the extent to which vestibular function is associated with sensorimotor behaviors (balance and falls) in AD (Aim 1a) and the extent to which cognition is associated with sensorimotor behaviors in adults with vestibular loss (Aim 1b). Explicit comparisons between those with AD and vestibular loss will also be made (Aim 1c) in order to determine potential similarities and inform ongoing fall prevention interventions in these patient populations. Existing measures will be combined with novel laboratory techniques in order to directly inform clinical practice and elucidate fundamental mechanisms underlying fall risk. The K01 award period will enable the PI to build upon her existing clinical and research expertise in vestibular science and provide structured training in the following areas: a) aging, b) cognition and cognitive impairment, c) advanced techniques for assessment of balance and gait, and d) advanced techniques for measuring eye movements. Research and training experiences during this award period will help the PI become an independent researcher in vestibular physiology. The proposed work will take place at Ohio State University under the mentorship of Dr. Dan Merfeld and Dr. Yuri Agrawal in conjunction with subject area specific mentorship from leaders in their respective fields. The proposed training activities and research plan are consistent with the NIDCD’s strategic plan for research in balance, specifically addressing current understanding of self-motion perception in health and disease and factors contributing to imbalance and falls in older adults. The proposed training will be the foundation for future R01 applications using advanced vestibular assessment techniques to examine changes in sensory function related to diverse pathologies and relationships to postural control.