Skip to Main Content
 

Global Search Box

 
 
 

ETD Abstract Container

Abstract Header

Uncovering Vestibular Contributions to Age-Related Imbalance

Wagner, Andrew Raymond
http://orcid.org/0000-0002-1833-766X
http://rave.ohiolink.edu/etdc/view?acc_num=osu1672875969330073

Abstract Details

2023, Doctor of Philosophy, Ohio State University, Health and Rehabilitation Sciences.
Falls are the leading cause of accidental injury and death among older adults, imbalance is a primary risk factor for falls, and vestibular impairment contributes to imbalance. However, despite decades of research linking vestibular lesions to imbalance, and a known age-related decline in vestibular function, the influences of specific age-related declines in vestibular sensation (i.e., semicircular canal vs. otolith vs. combined canal-otolith) on postural control are largely unknown. This project was designed to address this gap in the literature by using vestibular perceptual thresholds, an assay of vestibular noise, to determine how age-related changes to the signals originating from each vestibular end organ — semicircular canals, otolith organs, and their combined integration in the central nervous system — influence subclinical postural instability. In a sample of 52 healthy adults, ranging in age between 21 and 84 years (53.21±19.7 years), we determined the associations between these various source of vestibular noise and multiple domains of postural control — quiet stance balance under the manipulation of sensory cues (Chapter 3), reactive postural control during continuous pseudorandom platform tilts (Chapter 4), and anticipatory postural control during a battery of ambulatory balance tasks (Chapter 5). Our central hypothesis was that noise associated with the dynamic integration of canal and otolith inputs (assayed using 0.5 Hz roll tilt thresholds), would show the strongest associations with postural control secondary to the resulting imprecision in the dynamic estimation of head orientation relative to gravity. Our data partially supported this hypothesis, as we showed significant age-adjusted associations between roll tilt vestibular thresholds and (1) the variability in quiet stance postural sway when standing with the eyes closed and in the presence of unreliable proprioceptive cues (Chapter 3), (2) the variability in the postural response to continuous pseudorandom tilts of the support surface (Chapter 4), and (3) ambulatory balance as indicated by scores on the Functional Gait Assessment (Chapter 5). In addition to our main findings, the comprehensive nature of our vestibular threshold and postural control test batteries allowed us to identify novel contributions of the vertical canals (i.e.., RALP tilt thresholds) and of the saccules (i.e., Z-Translation thresholds). Specifically, we showed (1) that increased noise in the angular velocity signal originating from the vertical canals was associated with greater sway velocity in perturbed stance (Chapter 4) and (2) that Z-translation thresholds, an assay of noise in the saccule derived vertical acceleration signal, were associated with altered trunk kinematics during challenged gait (e.g., eyes closed walking, tandem gait) (Chapter 5). Collectively, these data show that adults with increased vestibular noise, on average, display greater postural instability within a variety of contexts. In addition, we showed that specific vestibular modalities (i.e., tilt vs. translation perception) were associated with distinct findings on postural control assessments. Therefore, although age-related changes to balance are multifaceted, these data suggest that age-related changes to vestibular sensation (i.e., increases in vestibular noise) represent at least one of the principal factors contributing to subclinical postural instability among otherwise healthy older adults.
Daniel Merfeld (Advisor)
260 p.
Neurosciences; Rehabilitation
vestibular; balance; perception; vestibular thresholds

Recommended Citations

Citations

  • Wagner, A. R. (2023). Uncovering Vestibular Contributions to Age-Related Imbalance [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1672875969330073

    APA Style (7th edition)

  • Wagner, Andrew. Uncovering Vestibular Contributions to Age-Related Imbalance. 2023. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1672875969330073.

    MLA Style (8th edition)

  • Wagner, Andrew. "Uncovering Vestibular Contributions to Age-Related Imbalance." Doctoral dissertation, Ohio State University, 2023. http://rave.ohiolink.edu/etdc/view?acc_num=osu1672875969330073

    Chicago Manual of Style (17th edition)

osu1672875969330073
34
© 2023, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.