Onset and evolution of dysphagia in Huntington’s Disease

Background Huntington's disease (HD) is a neurodegenerative disorder characterized by motor disturbances, cognitive decline and behaviour changes. Dysphagia is a well-recognized feature in advanced HD stage that leads to malnutrition and aspiration pneumonia, the latter representing the first causes of death in HD. However, no data are available about the onset of dysphagia during the disease course and the correlation between dysphagia severity and disease progression. Aim The aim of the study was to characterize dysphagia in patients with HD from early to advanced stages of the disease. Methods Dysphagia was investigated in 43 patients with HD by fiberoptic endoscopic examination of swallowing (FEES). FEES recordings were de-identified and assessed by a blinded judge. Dysphagia Outcome and Severity Scale (DOSS), Penetration-Aspiration Scale (PAS), and Yale Pharyngeal Residue Severity Rating Scale (YALE) were used to rate dysphagia severity, swallowing safety, and swallowing efficacy, respectively. For disease severity, all patients were assessed with the Unified Huntington's Disease Rating Scale (UHDRS) and were classified as early-stage, moderate-stage or advanced stage HD based on Shoulson-Fahn stages. Results FEES was well tolerated in all the subjects. Data showed that 30% of early-stage patients with HD already exhibit dysphagia (DOSS ≤5). Prevalence of dysphagia noticeably increased to 90% in the moderate stage of the disease, while reached 100% in the advanced stage. PAS scores progressively worsened with the disease stage. On the contrary, YALE scores remained stable in the various stages of disease and showed a greater amount of residue in the valleculae compared to pyriform sinus. A Total Motor Score of the UHDRS >37 correctly identified patients with dysphagia with 82% sensitivity and 73% specificity. Conclusion This study provides a better understanding of dysphagia onset and development in HD and may guide the definition of clinical care standard for dysphagia recognition and management, aimed at reducing nutritional and pulmonary complications.