Evaluation of Swallowing Function according to the Stage of Alzheimer's Disease

Background: Alzheimer's disease (AD) is a progressive neurodegenerative disease, and swallowing difficulties may occur as the disease progresses. Dysphagia has many consequences, such as aspiration and pneumonia. In particular, in the advanced stage, approximately 70% of the causes of death in AD involve aspiration pneumonia. Therefore, it is vital to assess the presence or absence of dysphagia in AD.

Objective: This study aims to describe swallowing difficulty across the stages of AD.

Methods: Thirty-five AD patients were evaluated. The Mini-Mental State Examination was conducted. A bedside water swallow test (BWST) and the Eating Assessment Tool (EAT-10) were administered. Finally, fiberoptic endoscopic evaluation of swallowing was used to evaluate residual, aspiration and penetration conditions.

Results: EAT-10 scores, BWST results, and penetration-aspiration status were statistically significantly different according to AD stage (p < 0.05). Among all patients, 74.3% had residue, 25.7% had penetration, and 2.9% had aspiration.

Conclusions: This study has demonstrated that swallowing dysfunction begins at a mild stage and progressively worsens toward the advanced stage in patients with AD. At all stages of AD, residue was observed, and this poses a risk for the development of penetration-aspiration. Therefore, it is necessary to evaluate the early dysphagia of individuals.