Swallowing Trajectories and DysPHagia Predictors in AlzheimER’s DisEase (SPHERE)

PROJECT SUMMARY Dysphagia frequently develops in persons with AD/ADRD and leads to serious health consequences, including increased caregiver burden, malnutrition, pneumonia, decreased quality of life, and mortality. Targeted, efficacious rehabilitative interventions for dysphagia have been developed in other neurodegenerative populations, but there are currently no effective treatments for dysphagia in AD/ADRD that have lasting effects on swallowing physiology. Prior to developing interventions to prevent dysphagia-related adverse sequelae in patients with AD/ADRD, in-depth understanding of factors contributing to dysphagia risk and trajectories of swallowing change across disease progression is urgently needed, especially in early stages when interventions can be most effective and impactful. Small, cross-sectional studies in AD/ADRD have suggested changes in swallowing beginning early in disease progression. However, these prior studies examining dysphagia in AD/ADRD lack the comprehensive and longitudinal characterization of swallowing function across the dementia continuum necessary to improve clinical management. Additionally, while novel, multi-modality swallowing assessments have enabled detection of subclinical swallowing impairments in other neurogenerative populations, the nature of subclinical changes in AD/ADRD remains unknown. To address these critical knowledge gaps, we propose a prospective cohort study of persons with AD/ADRD stratified by disease stage (very mild to moderate) and their care partners. Participants will undergo comprehensive dementia characterization, including neuropsychological testing and plasma-based biomarkers, as well as multi-modal swallowing assessments at baseline and every six months. We will also collect a variety of clinical factors (e.g., demographics, comorbidities) and measures of oral function (e.g., saliva production, oral health, lingual pressures), respiratory pressures, sarcopenia, and nutritional status at baseline. The overarching goal of this research is to inform development of intervention strategies for persons with AD/ADRD through enhanced clinical and epidemiologic understandings of the onset, nature, and progression of swallowing deficits. Our multidisciplinary team of experts will achieve this objective via the following specific aims: 1. Define swallowing changes from very mild to moderate AD/ADRD to: 1a) characterize subclinical dysphagia features; and 1b) identify clinical factors and swallowing measures that contribute to symptom reporting; 2. Identify risk factors for swallowing dysfunction from very mild to moderate AD/ADRD; and 3. Determine trajectories of change in swallowing function in persons with AD/ADRD and association with risk factors. The proposed work represents the first longitudinal, comprehensive study of swallowing function in a well-characterized cohort of persons with AD/ADRD. Improved understanding of swallowing function across disease progression will inform development of targeted interventions to address identification, prevention, and rehabilitation of dysphagia in AD/ADRD.