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Vocal Fold Atrophy in an Alzheimer's Disease Rat Model
Stephen Leong1, Carson S Miller1,2, Guzal Shukur1,2
1Department of Otolaryngology - Head & Neck Surgery, University of Washington School of Medicine, Seattle, WA, USA.
The Laryngoscope
|February 22, 2026
Summary
Alzheimer's disease (AD) in rats shows increased vocal fold bowing and thyroarytenoid (TA) muscle size, suggesting AD may cause vocal fold atrophy even in younger animals. Further research is needed.
Area of Science:
- Neuroscience
- Otolaryngology
- Pathology
Background:
- Advanced Alzheimer's disease (AD) is linked to voice impairment, dysphagia, and aspiration pneumonia.
- Vocal fold atrophy is a suspected contributor to these AD-related symptoms.
- Age is a confounding factor in studying vocal fold changes in AD.
Purpose of the Study:
- To investigate vocal fold atrophy in adult apolipoprotein E4 knock-in (ApoE4-KI) rats, a model for AD.
- To compare vocal fold characteristics in adult AD rats versus age-matched controls.
Main Methods:
- Endoscopic visualization of vocal folds in 4-month-old ApoE4-KI rats and controls.
- Histological analysis of the thyroarytenoid (TA) muscle.
- Calculation of vocal fold bowing index (BI) and TA myofiber cross-sectional area (CSA) and minimum Feret diameter (MFD).
Main Results:
- AD rats exhibited a significantly higher vocal fold bowing index (BI) compared to controls.
- TA myofiber average CSA and MFD were significantly larger in AD rats than in controls.
- A strong correlation was observed between BI and histological metrics.
Conclusions:
- Adult AD rats demonstrate significant vocal fold atrophy and increased TA muscle size compared to controls.
- These findings suggest AD pathology may induce vocal fold atrophy independent of advanced age.
- Further studies are required to elucidate the mechanisms underlying vocal fold atrophy in the AD model.
