Author ORCID Identifier

https://orcid.org/0000-0002-8051-1243

Defense Date

2026

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Health Related Sciences

First Advisor

Peter Pidcoe

Second Advisor

Teresa Kimberley

Third Advisor

Brooke Dexheimer

Fourth Advisor

Jiale Hu

Abstract

Persistent postural-perceptual dizziness (PPPD) is a common, disabling, chronic vestibular disorder whereby individuals experience symptoms of non-vertiginous dizziness, unsteadiness, and sway or rocking that are present most hours of the day, most days of the week. Individuals with PPPD have been noted to have an increased burden of dizziness and reduced quality of life compared to other dizziness diagnoses. The cause of PPPD is not well understood which can lead to years of diagnostic testing, failed therapies, and poor symptom management. It is important to understand PPPD pathophysiology so that optimal treatment interventions can be developed for this disorder to improve quality of life. Transcranial magnetic stimulation (TMS) is a tool that may be helpful to elucidate the underlying neurophysiological changes in individuals with PPPD. The purpose of this dissertation is to test for neurophysiological differences between individuals with PPPD and those without a dizziness disorder as measured by single pulse TMS during three different visual conditions, as well as to explore the relationship between TMS measures and levels of self-reported functional limitations in individuals with PPPD. This study used a cross-sectional, quasi-experimental, repeated measures design and was guided by Sensory Weighting Theory. Results showed that corticospinal excitability, as measured by motor evoked potential (MEP) peak to peak amplitude, demonstrated the same pattern of change across both individuals with PPPD and healthy controls with a gradual increase in MEP amplitude noted as testing progressed from an eyes open to an eyes closed to a visually stimulating condition. Statistically significant differences were found between all visual conditions but there were no between group differences. Intracortical inhibition, as measured by cortical silent period duration (cSP), demonstrated no statistically significant differences between groups or across visual conditions.

Findings from this study contribute to understanding of the neurophysiological changes that occur related to different visual input during standing postural control. These findings provide much needed information about the underlying pathophysiology of individuals with PPPD and may help in the future development of effective and personalized physical therapy interventions tailored to meet different visual environments.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

7-6-2026

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