Am J Speech Lang Pathol. 2026 Jun 24:1-15. doi: 10.1044/2026_AJSLP-25-00087. Online ahead of print.
ABSTRACT
PURPOSE: Dysarthria, drooling, and swallowing disorders are common motor problems in people with Parkinson’s disease (PwP), leading to significant physical, emotional, and functional impairments that compromise quality of life. However, evidence on the progression of these disorders and their relationship with other features of Parkinson’s disease (PD) remains scarce. This study aimed to investigate the progression of dysarthria, drooling, and swallowing disorders in PwP and identify predictors of progression.
METHOD: A 1-year prospective cohort study was conducted with 73 PwP. Dysarthria was assessed using the Frenchay Dysarthria Assessment-Second Edition (FDA-2), drooling with Item 2.2 (Saliva and drooling) of the Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS), and swallowing with the Swallowing Clinical Assessment Score in Parkinson’s Disease (SCAS-PD). The FDA-2 and SCAS-PD rely on clinician assessment, whereas MDS-UPDRS Item 2.2 (Saliva and drooling) assesses patient-reported problems with saliva control. The Wilcoxon signed-ranks test for paired samples was used to compare baseline and 1-year follow-up scores, and linear regression was used to identify predictors of progression.
RESULTS: Dysarthria worsened significantly (p < .001) after 1 year and was predicted by poorer cognitive (β = -.02; SE = 0.01; p = .02) and motor performance (β = .48; SE = 0.21; p = .03). Drooling and swallowing showed a trend toward deterioration, although these changes were not statistically significant (p > .05).
CONCLUSIONS: After 1 year, dysarthria worsened significantly, while drooling and swallowing showed a tendency to decline, but did not reach statistical significance. Assessments based on clinician and patient reports may have limited sensitivity to subtle changes. Dysarthria progression reflected overall PD severity, with poorer cognitive and motor performance emerging as key predictors. These findings highlight the importance of routine clinical monitoring of these domains and support future studies using instrumental assessments (e.g., acoustic analysis and videofluoroscopic swallow studies) to better capture progression in dysarthria, drooling, and swallowing disorders.
SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.32764596.
PMID:42340753 | DOI:10.1044/2026_AJSLP-25-00087