Dysphagia in Huntington's Disease: An Evaluation of Swallowing Disturbance across the HD-ISS Staging Spectrum.

The onset and pattern of progression of swallowing impairment in HD remain poorly understood. The Swallowing Disturbance Questionnaire (SDQ) has proven useful in assessing dysphagia across various neurological conditions, but its use in HD remains largely unexplored. To evaluate swallowing difficulties in HD using the SDQ and Huntington's Disease Integrated Staging System. The SDQ was administered to 87 gene positive subjects stratified into HD-ISS Stages 0/1 (n = 27), 2 (n = 21), and 3 (n = 39). Kruskal-Wallis was used to compare performance among cohorts and partial eta-squared (η2) was used to calculate effect sizes. Spearman's rho (r) was used to calculate correlations. Total swallowing disturbance score significantly differed across HD-ISS stages (ηp2 = 0.20, p < 0.001), with similar trends and strong effect sizes for both oral (ηp2 = 0.15, p < 0.001) and pharyngeal (ηp2 = 0.12, p < 0.001) phases. Within cohorts, total swallowing disturbance score was significantly different between Stages 0/1 and 2 (p = 0.007), Stage 2 and 3 (p = 0.02) and between Stages 0/1 and 3 (p < 0.001). Using quartile-based severity cut-points (Mild: 0-6, Moderate: 7-14, Severe: >14), 92.6% Stage 0/1 related mild swallowing problems, 7.4% of Stage 0/1 reporting moderate difficulties. In Stage 2, 28.5% described moderate and over 25% reported severe issues. Among Stage 3 subjects, one-third reported moderate and almost half experienced severe swallowing difficulties. Swallowing disturbances emerge early and progressively worsen across the HD-ISS staging spectrum, with both oral and pharyngeal phases affected. These findings suggest that early assessment of swallowing function is warranted in HD clinical care.