2026 Theses Doctoral

Salivary Dysfunction and Airway Protection in Parkinson’s Disease

Villarreal Cavazos, Katya

Saliva production and airway protection (cough and swallowing) are impaired in people with Parkinson’s Disease (PD), placing individuals at higher risk for aspiration pneumonia – a leading cause of death in this population. However, these functions are often studied in isolation, and as a result, the relationship between salivary dysfunction, and airway protection deficits remains poorly understood in this population. Saliva production, cough and swallowing are closely linked physiological processes. Beyond its critical role in the oral cavity, saliva is found in the pharynx and larynx, and plays an important role in providing adequate mucosal fluidification – critical for laryngeal sensitivity and protecting the airway from respiratory agents. Impairments in either saliva production, management, composition, or in airway protection (swallowing or cough) significantly increase an individuals’ risk of respiratory compromise, morbidity, and mortality. Despite this, our understanding of salivary changes in this population remains poorly understood. Additionally, to our knowledge, the relationship between salivary changes and airway protection deficits in individuals with PD remains unexplored.

Thus, to address this important scientific gap, this dissertation includes two research studies aimed at understanding the association between saliva measures, patient characteristics and airway protection deficits in individuals with PD. Chapter 1 will provide an overview of the existing literature on saliva quantity, management, and composition, as well as airway protection deficits in this population. It will expand on the anatomical and physiological overlap between saliva, swallowing and cough. Chapter 2 will examine the association between saliva management and saliva quantity in a single cohort of individuals with PD. Chapter 2 will also investigate the association between salivary changes and patient specific characteristics that might influence salivary changes. Chapter 3 will then explore the relationship between saliva quantity, composition, and measures of airway protection in a single cohort of individuals with PD and co-occurring airway protection deficits. This dissertation will conclude with Chapter 4 where the findings from chapter 2 and 3 will be synthesized, and future research directions will be addressed.