Work

Vocal Fold Atrophy in an Alzheimer's Disease Rat Model

Year: 2026

Type: article

Abstract: OBJECTIVES: Advanced Alzheimer's disease (AD) is associated with impaired voice, oropharyngeal dysphagia, and aspiration pneumonia. Vocal fold atrophy is hypothesized to contribute to these changes. While vocal fold atrophy is observed in AD, advanced age is co-prevalent and a confounding variable. The apolipoprotein E4 knock-in (ApoE4-KI) rat model is commonly used to study cognitive and motor changes in AD. This study aims to compare vocal fold atrophy in adult AD rats vs. age-matched controls. METHODS: Vocal folds were visualized endoscopically in 4-month ApoE4-KI rats (n = 12) and age-matched controls (n = 8) following anesthesia. The thyroarytenoid (TA) muscle was collected for histology. Vocal fold bowing index (BI) was calculated from endoscopic still images by two blinded reviewers using digital software. Digital myofiber analysis was used to calculate TA myofiber average cross-sectional area (CSA) and minimum Feret diameter (MFD). RESULTS: ), 586.3 ± 76.9 vs. 435.8 ± 49.4, difference 150.5 with 95% CI 91.2-209.9, p < 0.01; MFD (μm), 23.0 ± 1.1 vs. 19.8 ± 1.3, difference 3.2 with 95% CI 2.0-4.4, p < 0.01). CONCLUSION: Non-aged AD rats had significantly higher BI and TA myofiber size than controls. BI was strongly correlated with histologic metrics. These findings suggest that AD may lead to greater vocal fold atrophy in non-aged animals. Additional studies are needed to determine the mechanism(s) for vocal fold atrophy in this model. LEVEL OF EVIDENCE: N/A.

Source: The Laryngoscope

DOI: 10.1002/lary.70433